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Digitized  by  tine  Internet  Archive 

in  2010  witii  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/americantextbook1911kirk 


LIST  OF   rOXTRIBUTORS. 


ANGLE,   EDWARD   H.,   M.D.,  D.D.S. ; 

CAPON,  W.  A.,   D.D.S.  ; 

CASE,  CALVIN   S.,   M.D.,   D.D.S.; 

CRENSHAW,  WILLIAM,   D.D.S.; 

CRYER,  M.   H.,  M.D.,  D.D.S.; 

DARBY,   EDWIN  T.,   M.D.,   D.D.S.  ; 

GODDARD.  C.   L.,  D.D.S.  ; 

GUILFORD,  S.   H.,  A.M.,   D.D.S.,   Ph.D.; 

INGLIS,  OTTO   E.,   M.D.,   D.D.S.; 

JACK,  LOUIS,   D.D.S.; 

KIRK,   EDWARD  C,   D.D.S.,   Sc.D.  ; 

NOYES,  FREDERICK   B.,   B.A.,  D.D.S.; 

OTTOFY,   LOUIS,   D.D.S.; 

PRINZ,   HERMANN,  M.D.,  D.D.S.; 

THOMPSON,  ALTON   HOWARD,   D.D.S. 

TRUMAN.  JAMES,   D.D.S.,   LL.D.  ; 

WARD,   MARCUS  L.,  D.D.Sc.  ; 

WEEKS,  THOMAS  E.,   D.D.S. 


THE 


AMERICAN  TEXT-BOOK 


OPERATIVE  DENTISTRY. 


m  CONTRIBUTIONS  BY  EMINENT  AUTHORITIES. 


EDITED   BY 

EDWARD  C.  KIRK,  D.D.S.,  Sc.D., 

Professor  of   Dental,   Pathology,   Therapeutics,  and   Materia  Medica,  and  Dean   of   the 

Dental  Department  of  the  University  of  Pennsylvania,  Philadelphia;  Editor  of 

"  The   Dental   Cosmos;"   Officier  de  l'AcadiSmie   de  France. 


FOURTH  EDITION,   REVISED  AND  ENLARGED. 


ILLUSTRATED   WITH    1015    ENGRAVINGS. 


LEA  &  FEBIGER, 

PHILADELPHIA   AND    NEW   YORK. 

1911 


T  K  ^'0  i 

\<  (.  3 
1S\I 


Entered  according  to  Act  of  Congress  in  the  year  1911,  by 

LEA   &   FEBIGER, 

in  the  Office  of  the  Librarian  of  Congress  at  Washington.     All  rights  reser\^ed. 


WITH   THE   CONSENT  OF  THE  CONTRIBUTORS 


THIS  BOOK  IS  DEDICATED  TO 


JAMES   TRLTjMAISr,    D.  D.  S.,    L.L.  D., 

THE    CHARACTERISTIC   OF  WHOSE    LONG    PROFESSIONAL    CAREER    HAS 

BEEN  THE  INCULCATION  OF  THE  PRINCIPLES  UPON 

WHICH   THE  WORK  IS   BASED. 


PREFACE 


The  demand  for  a  new  edition  of  the  American  Text-book  of  Operative 
Dentistry  has  necessitated  much  more  than  a  mere  revision  of  the 
previous  text.  The  work  has  been  largely  ^e^^Titten,  and  the  fourth 
edition  is  therefore  practically  a  new  book.  Such  a  radical  change 
has  been  rendered  necessary  by  the  rapid  evolution  which  has  taken 
place  throughout  the  entire  domain  of  the  science  and  art  of  dentistry 
since  the  publication  of  the  previous  edition.  The  accumulation  of 
new  data,  the  investigation  of  the  deeper  problems  of  dental  science, 
and  the  modification  exerted  by  these  factors  upon  the  practice  of 
dentistry  have  wrought  changes  that  in  certain  departments  are  little 
less  than  revolutionary.  So  rapid  and  far-reaching  in  their  effects  are 
many  of  the  changes  which  have  taken  place  that  the  whole  subject  of 
operative  dentistry  has  been  and  still  is  in  a  state  of  flux. 

The  mirroring  of  the  progressive  movement  in  operative  dentistry 
will  be  evident  in  the  plan  as  well  as  in  the  text  of  this  work.  The 
subject  of  cavity  preparation  is  treated  as  a  technic  procedure,  first, 
because  it  can  be  most  intelligently  comprehended  as  such,  and 
further,  because  the  work  is  primarily  intended  for  the  instruction  of 
the  undergraduate  student.  It  is  fully  recognized  that  the  scientific 
basis  of  such  subjects  as  pyorrhea  alveolaris,  tooth  discoloration,  tooth 
extraction,  root-canal  treatment,  orthodontia,  etc.,  is  much  more  fully 
elaborated  in  the  present  work  than  would  be  justifiable  in  a  treatise 
or  text-book  devoted  exclusively  to  operative  dentistry  as  an  art;  but 
as  there  still  appears  to  be  a  demand  upon  the  part  of  students  for  a 
volume  furnishing  a  comprehensive  view  of  the  fundamental  principles 
upon  which  alone  an  intelligent  and  rational  practice  may  be  based, 
the  treatment  of  the  subject  of  operative  dentistry  in  the  present  work 
has  been  extended  to  include  those  principles. 

Certain  differences  of  opinion  will  be  occasionally  manifest  in  the 
work  in  the  treatment  of  allied  subjects  by  difterent  authors.  ^\liile 
such  differences  are,  of  course,  not  desirable  in  a  work  intended  for  the 
use  of  untrained  students,  and  while  no  conflict  of  opinion  will  be 
noticed  with  respect  to  established  scientific  principles,  it  is  manifestly 
impossible  to  secure  unanimity  upon  subjects  which  have  not  as  yet 

(vii)     . 


viii  PREFACE 

reached  a  stage  of  development  entitling  them  to  classification  among 
the  exact  sciences.  For  example,  the  imsettled  (luestion  whether  under 
any  circumstances  extraction  is  a  justifiable  operation  in  connection 
with  the  correction  of  malocclusion,  has  led  to  dift'erences  of  opinion 
that  are  not  at  present  reconcilable,  and  cannot  be  until  a  larger  body 
of  evidence  based  upon  observation  and  experience  has  been  submitted 
at  the  bar  of  professional  judgment. 

The  Editor  takes  this  occasion  to  express  his  deep  sense  of  appre- 
ciation of  the  uniform  courtesy  and  spirit  of  helpfulness  which  have 
characterized  the  attitude  of  all  of  his  collaborators  in  this  work,  for 
their  patience  under  his  suggestions,  and  their  willingness  to  sacrifice 
personal  interests  to  the  thoroughness  and  accuracy  of  the  work  as  a 
whole.  To  the  publishers  his  thanks  are  due  for  their  unhesitating 
cooperation  in  every  effort  which  tended  to  the  completeness  of  the 
work  in  all  its  phases,  and  he  is  likewise  und(>r  obligation  to  his 
colleague,  Dr.   Riethmiiller,  for  the  preparation  of  the  accurate  and 

copious  index. 

The  Editor  assumes  personal  responsibility  for  the  nomenclature  used 
throughout,  and  in  submitting  the  \olume  to  the  critical  consideration 
of  his  fellow-teachers  and  his  larger  circle  of  fellow-students  he  can 
hope  for  it  no  more  generous  treatment,  nor,  indeed,  could  he  expect 
more,  than  has  been  so  freely  accorded  to  its  predecessors. 

E.  C.  K. 

University  of  Pennsylvania,  1911. 


LIST  OF  CONTRIBUTORS 


EDWARD  H.  ANGLE,  M.D.,  D.D.S., 

Presuiont  of  the  Angle  School  of  Orthodoiif  ia,  Now  Tvoiidon,  Conn. 

W.  A.  CAPON,  D.D.S., 

Lecturer  on  Dental  Ceramics  in  the  University  of  Pennsylvania,  Phila(le!j)liia. 

CALVIN  S.  CASE,  M.D.,  D.D.S., 

Professor  of  Orthodontia,  Chicago  College  of  Dental  Surgery,  Chicago,  111. 

WILLIAM  CRENSHAW,  D.D.S., 

Dean  and  Professor  of  Operative  Dentistry  and  Dental  Pathology,  Atlanta 
Dental  College,  Atlanta. 

M.  H.  CRYER,  M.D.,  D.D.S., 

Professor  of  Oral  Surgery  in  the  Dental  Department  of  the  University  of 
Pennsylvania,  Philadelphia. 

EDWIN  T.  DARBY,  M.D.,  D.D.S., 

Professor  of  Operative  Dentistry  and  Dental  Histology  in  the  University  of 
Pennsylvania,  Philadelphia. 

C.  L.  GODDARD,  D.D.S., 

Late  Professor  of  Orthodontia,  University  of  California,  College  of  Dentistry, 
San  Francisco,  Cal. 

S.  H.  GUILFORD,  A.M.,  D.D.S.,  Ph.D., 

Professor  of  Operative  and  Prosthetic  Dentistry  and  Dean  of  the  Philadel- 
phia Dental  College,  Philadelphia. 

OTTO  E.  INGLIS,  M.D.,  D.D.S., 

Professor  of  Dental  Pathology  and  Therapeutics  in  the  Philadelphia  Dental 
College,  Philadelphia. 

LOUIS  JACK,  D.D.S., 

Pliiladelphia. 

EDWARD  C.  KIRK,  D.D.S.,  Sc.D., 

Professor  of  Dental  Pathology,  Therapeutics,  and  Materia  Medica,  and  Dean 
of  the  Department  of  Dentistry  in  the  University  of  Pennsylvania,  Phila- 
delphia; Officier  de  I'Academie  de  France. 

FREDERICK  B.  NOYES,  B.A.,  D.D.S., 

Professor  of  Dental  Histology  in  the  Northwestern  LTniversity  Dental  School, 
Chicago,  III. 

LOUIS  OTTOFY,  D.D.S., 

Professor  of  Clinical  Therapeutics,  Chicago  College  of  Dental  Surgery, 
Chicago;  Attending  Dental  Surgeon,  St.  Luke's  Hospital,  Manila,  P.  I. 

(ix) 


X  /-/.ST  OF  COXTRIIiUTORS 

HERMANN  PRINZ,  M.D.,  D.D.S., 

Professor  of  Materia  Medica,  Therapeuties,  ami  I'alliolo^^y  in  (lie  \\  asliirinton 
University  Dental  School,  St.  Louis,  Mo. 

ALTON  HOWARD  THOMPSON,  D.D.S., 

Professor  of  Dental  Anatomy,  Kansas  ( 'ity  1  )eiital  ( "olIcKe,  Kansas  C'it^',  Mo. 

JAMES  TRUMAN,  D.D.S.,  LL.D., 

Emeritus  Professor  of  Dental  Pathology,  Therapeutics,  and  Materia  Medica 
in  the  University  of  Pennsylvania,  Philadelphia. 

MARCUS  L.  WARD,  D.D.Sc, 

Profe.ssor  of  Dental  Physics  and  Chemist r^-  in  the  University  of  Michigan, 
Ann  Arbor,  Mich. 

THOMAS  E.  WEEKS,  D.D.S., 

Professor  of  Dental  Anatomj-,  Operative  Technique,  and  Clinical  Dentistrj' 
in  the  Philadelphia  Dental  College,  Philadelphia;  Author  of  Weeks' 
Technique. 


CONTENTS 


CHAPTER  I 

HUIMAN  ODONTOGRAPHY •       17 

By  Alton  Howard  Thompson,  D.D.S. 

CHAPTER  n 

DENTAL  HISTOLOGY  ^YITH  REFERENCE  TO  OPERATIVE  DEN- 
TISTRY     56 

By  Frederick  B.  Noyes,  B.A.,  D.D.S. 

CHAPTER  HI 

ANTISEPSIS  IN  DENTISTRY 118 

By  James  Truman,  D.D.S. ,  LL.D. 

CHAPTER  IV 

EXAMINATION  OF  THE  TEETH  AND  ORAL  CAVITY  PRELIMINARY 
TO  OPERATION— REMOVAL  OF  DEPOSITS— APPLIANCES  AND 
METHODS— RECORDING  RESULTS 135 

By  S.  H.  Guilford,  A.M.,  D.D.S.,  Ph.D. 

CHAPTER  V 

CREATING  INTERDENTAL  SPACES  PREPAJIATORY  TO  FILLING 

—  GRADUAL     SEPARATION  —  IMMEDIATE     OR     FORCIBLE 
SEPARATION 140 

By  S.  H.  Guilford,  A.M.,  D.D.S.,  Ph.D. 

CHAPTER  VI 

MODIFICATION  OF  DENTINAL  SENSITIVITY  BY  DEHYDRATION 

—  TOPICAL    MEDICATION  —  ELECTRICAL    OSMOSIS  —  GEN- 
ERAL ANESTHESIA 145 

By  S.  H.  Guilford,  A.M.,  D.D.S.,  Ph.D. 

(xi) 


xii  CONTENTS 

CHAPTER  \\\ 

TECHNIQUE  OF  CA^  rrv   PREPARATION lo.l 

By  Thomas  E.  Weeks,  D.D.S. 

CHAPTER  \\U 

EXCLUSION  OF  MOISTURE— EJECTION  OF  THE  SALIVA— APPLI- 
CATION OF  THE  DAM  IN  SIMPLE  CASES,  AND  IN  SPECIAL 
CASES  PRESENTING  DIFFICULT  COMPLICATIONS— NAPKINS 
AND  OTHER  METHODS  FOR  SECURING  DRYNESS     ....     191 

By  Louis  Jack,  D.D.S. 

CHAPTER  IX 

THE  OPERATION  OF  FILLING  CAVITIES  WITH  METALLIC  FOILS 

AND    THEIR   SEVERAL    MODIFICATIONS 201 

By  Edwin  T.  Darby,  D.D.S.,  M.D. 

CHAPTER  X 

USE  OF  THE  MA^IllTX  IN  FILLING  OPERATIONS 23') 

By  William  Crenshaw,  D.D.S. 

CHAPTER  XI 

PLASTICS 202 

By  Marcus  L.  Ward,  D.D.Sc. 

CHAPTER  XII 

COMBINATION  FILLINGS 324 

By  Marcus  L.  Ward,  D.D.Sc. 

CHAPTER  XIII 

RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 333 

By  W.  a.  Capon,  D.D.S. 

CHAPTER  XIV 

THE  TREATMENT  AND  FILLING  OF  ROOT  CANALS     ....     391 

By  Otto  E.  Incjlis,  D.D.S. 


CONTENTS  xiii 

CIIAITKR  XV 

PYOKIMII'IA  AI.VMOI.AIIIS 464 

By  Edwaki)  C  Kirk,  D.D.S.,  Sc.l). 

CHAPTER  XVI 

DISCOLORED  TEETH  AND  THEIR  TREATMENT 519 

By  Edward  C.  Kirk,  D.D.8.,  Sc.D. 

CHAPTER  XVH 

EXTRACTION  OF  TEETH 545 

By  M.  H.  Cryer,  M.D.,  D.D.S. 

CHAPTER  XVHI 

LOCAL  ANESTHESIA 623 

By  Hermann  Prinz,  M.D.,  D.D.S. 

CHAPTER  XIX 

PLANTATION  OF  TEETH 546 

By  Louis  Ottofy,  D.D.S. 

CHAPTER  XX 

MANAGEMENT  OF  DECIDUOUS  TEETH 664 

By  Clark  Goddard,  A.M.,  D.D.S. 

CHAPTER  XXI 

ORTHODONTIA 683 

By  Edward  H.  Angle,  M.D.,  D.D.S. 

CHAPTER  XXII 

DENTO-FACIAL  ORTHOPEDIA 873 

By  Calvin  S.  Case,  D.D.S.,  M.D. 

CHAPTER  XXIII 

ORAL  PROPHYLAXIS 910 

By  S.  H.  Guilford,  A.M.,  D.D.S.,  Ph.D. 


I N  T  K  ()  D  U  C  T  (3  R  Y. 


A  STUDY  of  the  advances  which  have  of  recent  years  taken  place  in 
the  field  of  Operative  Dentistry  will  reveal,  besides  the  important  addi- 
tions to  our  knowledge  in  the  shape  of  novel  methods  and  improved 
technique,  a  vastly  more  important  advance  manifested  in  a  better  and 
more  general  understanding  of  scientific  principles,  and  the  application 
of  dental  science  to  dental  art,  resulting  in  a  more  rational  practice. 
Especially  is  this  true  in  regard  to  the  etiology  of  dental  and  oral 
pathological  conditions,  and  the  rationale  of  the  modes  of  treatment 
indicated  for  the  morbid  states  constantly  confronting  the  dental 
practitioner. 

The  modifications  in  surgical  methods  and  the  greatly  improved 
results  "which  are  the  outgrowth  of  modern  scientific  studies  in  bacterial 
pathology,  while  they  have  made  a  considerable  impress  upon  dental 
operative  methods,  have  not,  however,  received  that  universal  practical 
acceptance  among  dental  operators  which  their  immense  importance 
demands.  There  is  no  field  of  special  surgery  in  which  the  import- 
ance of  exact  knowledge  wdth  respect  to  aseptic  and  antiseptic  treat- 
ment is  more  marked  than  in  the  practice  of  dentistry.  The  dental 
operator  is  continually  confronted  with  septic  conditions,  so  that  pre- 
cise knowledge  of  their  origin,  causes,  i^henomena,  and  treatment  are 
essentials  to  the  legitimate  practice  of  the  profession. 

The  performance  of  any  operation,  and  especially  those  which  are 
classified  as  capital,  with  unclean  hands  or  infected  instruments  would 
in  the  present  stage  of  surgical  art  be  regarded  as  criminal  malpractice. 
It  should  be  so  considered  in  dentistry.  The  loss  of  a  patient's  life  as 
the  result  of  surgical  septic  infection  is  no  longer  permissible.  Lack 
of  antiseptic  precautions,  in  certain  dental  operations  may  directly  lead 
to  and  as  a  matter  of  fact  has  been  the  cause  of  fiital  results.  It  has 
been  shown  conclusively  ^  that  a  large  variety  of  pathogenic  micro- 
organisms are  almost  constant  inhabitants  of  the  oral  cavity.  In  addi- 
tion to  the  numerous  forms  which  bring  about  an  acid  reaction,  there 
are  many  specific  organisms  which  produce  in  inoculated  animals 
pyemia  and  septicemia  in  their  several  clinical  classes.  But  while  the 
dental  practitioner  is  not  often  called  upon  to  face  the  issues   of  life 

^  W.  D.  Miller,  Dental  Cosmos,  November,  1891. 

15 


16  lyTRODCCTOliV. 

and  (lentil  in  tlic  course  of  his  woi-k,  his  re<j)oii>il)ilities  as  related  to 
the  issues  with  which  he  docs  deal  demand  ol"  him  the  same  care  and 
thoroughness  in  order  to  attain  tiie  character  of  result  which  the  pos- 
sibilities of  modern  dentistry  require  of  him.  In  the  following  pages 
the  importance  of  asepsis  and  antisepsis  in  dental  operations  is  con- 
stantly impressed  upon  the  mind  of  the  student. 

By  the  term  nsqms  is  specifically  meant  the  condition  under  which 
are  excluded  those  influences  or  causes  which  induce  infection  by  patho- 
genic micro-organisms ;  when  a  tissue  or  surface  has  been  rendered 
germ-free  it  is  said  to  be  in  an  aseptic  condition.  By  (inti.srp.sis  is 
meant  the  means  by  which  the  septic  state  is  comljated  or  the  aseptic 
state  is  attained. 

Under  the  aseptic  condition  repair  of  tissues  takes  place  normally 
without  interference,  wounds  and  injuries  heal  with  a  minimum  of  dis- 
turbance, and  the  inflammatory  concomitant  is  of  the  simple  traumatic 
type,  without  suppuration  or  tendency  to  diffusion. 

The  aseptic  state,  in  many  operations  in  the  mouth,  is  not  readily 
attainable  and  cannot  be  maintained  for  anv  lentjth  of  time  ;  but  in  all 
operations  which  involve  the  pulp  and  pulp  chamber,  as  well  as  the 
periapical  region  through  the  pulp  canals  of  teeth,  strict  aseptic  con- 
ditions, as  regards  external  infection,  are  perfectly  attainable  through 
exclusion  of  the  oral  secretions  by  means  of  rubber  dam,  the  use  of 
suitable  disinfectants,  and  sterilized  instruments.  It  is  the  class  of 
operations  here  alluded  to  which  are  most  prolific  of  disturbance  from 
infective  inflammations  caused  by  ignorant  or  careless  manipulation. 

The  time  is  at  hand,  if  indeed  it  has  not  already  arrived,  when  puru- 
lent inflammations  fi)llowing  dental  treatment  will  be  regarded  with 
the  same  condemnation  by  the  dentist  as  by  the  general  surgeon.  The 
operative  section  of  this  work  is  written  in  full  recognition  of  the  prin- 
ciples here  indicated. 


OPERATIVE  DENTISTRY 


CHAPTER    I 
HUMAN  ODONTOGR.IPHY 

By  ALTON  HOWARD  THOMPSON,  D.D.S. 

The  teeth  are  located  at  the  portal  of  the  alimentary  system  of  the 
animal  organism.  They  help  to  differentiate  in  the  choice  of  the  elements 
of  nutrition  and  reduce  these  elements  to  digestible  condition.  The  dental 
armament  is,  therefore,  the  first  and  chief  factor  in  the  mechanism  of 
alimentation.  The  teeth  are,  morphologically,  transformed  tissues 
belonging  to  the  tegmnentary  system  of  animals,  and  are  hard,  calcareous 
bodies,  situated  in  the  oral  cavity  at  the  anterior  orifice  of  the  alimentary 
canal.  In  the  lower  vertel)rates  they  may  be  scattered  over  all  of  the 
bones  and  cartilages  surrounding  the  mouth,  l)ut  in  the  mammals,  as  in 
man,  they  are  confined  to  the  upper  and  lower  jaws  only.  Tlie  name 
teeth,  is  therefore,  in  the  latter,  especially  applied  to  those  structures 
located  in  the  oral  cavity  which  contain  a  calcified  tissue  known  as 
dentine. 

Tlie  mai)i  function  of  the  teeth  is  the  prehension  and  mechanical  sub- 
division and  reduction  of  substances  employed  for  food,  preparatory 
to  digestion.  The  main  divisions  of  this  function  are:  (1)  Prehension, 
or  the  seizing  of  food  sulistances ;  (2)  division,  or  cutting  into  pieces;  (3) 
mastication,  or  comminution  into  small  particles,  and  (4)  insalivation,  or 
the  mixing  of  food  with  the  oral  secretions.  For  the  performance  of  these 
various  functions,  diflFerent  forms  of  teeth  are  developed  in  different 
animals  in  great  variety.  For  the  office  of  prehension,  long  trenchant 
canines  are  developed  in  lower  mammals,  but  in  man  these  teeth  are 
reduced  to  the  level  of  the  other  teeth.  Division  and  cutting  are  per- 
formed by  the  incisors,  which  are  well  developed  in  man.  Crushing  and 
mastication  are  performed  by  the  premolars  and  molars,  which  in  man 
are  much  reduced  and  modified,  owing  to  his  omnivorous  diet.  The 
denture  of  man  is  midway  between  the  extreme  form  of  the  carnivora,  on 
the  one  hand,  and  herbivora,  on  the  other.  Food  selection  has  reduced 
the  denture  of  man  to  a  simple  type,  which  is  quite  primitive,  showing 
evidences  of  reversion.  The  functions  of  the  teeth  in  man  being  less 
2  (17) 


18  IIUMAX  ODOSTOGRAPIIY 

specialized  (liaii  in  lower,  hifjhly  speeiali/ed  animals,  his  (jentiire 
is  eorrespoiulin^ly  reduced,  function  Ix'inii  iiere,  as  ever,  the  cause  and 
sustainer  of  structure. 

The  primitive  tooth  form  is  that  of  the  simj>le  cone.  This  is  still  found 
in  the  teeth  of  fisiies,  reptiles,  and  some  lower  mannnals.  The  more 
complicated  teeth  of  the  hii^her  mammals  have  been  formed  hy  the 
modification  of  the  single  cone.  Thus  the  incisors  and  canines  are  com- 
posed of  single  cones,  the  bicuspids  of  two  cones  fused  together,  and  the 
molars  are  formed  of  three  or  more  cones  arranged  to  form  triangular 
or  (juadrangular  crowns.  In  the  genesis  of  tooth  forms,  theiefore,  the 
complex  teeth,  as  the  bicuspids  and  molars,  are  formed  by  the  repetition 
and  addition  of  cones  and  their  accompanying  cusps,  both  laterally  and 
longitudinally  of  the  jaw.  The  transition  from  single  to  complex  teeth 
is  accomplished  by  the  repetition  of  the  single  cone  in  various  directions. 
Thus  a  bicuspid  is  formed  1)V  the  evolution  of  a  cingule  upon  the  lingual 
side  of  the  buccal  cone,  which  gradually  develops  into  a  lingual  cone  with 
cusp  and  root,  as  illustrated  in  the  double  cone  shape  of  the  upper  first 
bicuspid  of  man.  The  upper  molar  crown  is  developed  as  follows:  The 
primitive  simple  cone,  the  primordial  element,  is  called  the  protocone. 
The  first  cone  (Fig.  1,  A)  and  the  first  step  in  molar  formation  is  the 
growth  of  cusps  upon  the  mesial  and  distal  aspects  of  the  protocone  (Fig. 
1,  B).  The  mesial  cusp  is  called  the  paracolic  and  the  distal  the  mciacone. 
This  gives  three  cusps  in  a  mesio-distal  line,  forming  a  three-coned 
crowai  called  the  triconodont  type.  This  is  the  type  of  the  early  forms 
of  the  mammalian  molar  teeth,  and  is  still  preserved  in  some  of  the  car- 
nivora,  seals,  lemures,  etc.  The  next  stage  is  the  shifting  of  the  cones  so 
as  to  alter  their  relative  positions  to  form  a  triangle  (Fig.  1,  C).  In  the 
upper  jaw  the  protocone  moves  to  the  lingual  side  and  becomes  the  mesio- 
lingual  cusp,  leaving  the  paracone  as  the  mesio-buccal  cusp  and  the 
metacone  as  the  disto-buccal  cusp,  which  come  together  on  the  buccal 
side,  thus  forming  the  trigon  of  the  upper  molar.  This  is  the  trituber- 
cular  crown  of  early  geological  times  from  which  all  other  molar  types 
were  developed,  and  is  still  preserved  in  the  opossum,  some  insectivora, 
and  some  other  modern  mammals.  In  the  lower  molars  the  primitive 
cone  is  called  the  protoconid,  but  it  moves  to  the  buccal  side  and  becomes 
the  mesio-buccal  cusp.  The  paraconid  has  l)een  aborted  in  man,  so  that 
the  metaconid  becomes  the  mesio-lingual  cusp,  which  forms  the  trigonid 
of  the  lower  molar  crown.  Thus  the  triangles  of  the  upper  and  lower 
molars  alternate — the  apex  of  the  upper  molar  being  directed  lingually 
and  the  lower  bucally,  so  that  they  pass  each  other  with  a  shear-like 
motion.  The  next  stage  in  the  evolution  of  the  molar  crowns  is  the  addi- 
tion to  the  trigon  of  the  upper  molar  on  its  disto-lingual  face,  of  a  heel, 
or  talon  (Fig.  1,  Z)),  which  supports  the  fourth  cusp,  the  hypocoiie,  which 
strikes  into  the  centre  of  the  trigonid  of  the  lower  molar,  like  a  pestle  into 
a  mortar.    Then  there  is  added  to  the  trigonid  of  the  lower  molar  on  its 


77/ A'   1)I-:NT.\L   Mi'C/l 


19 


distal  side,  a  licel,  or  taioiiid,  which  suj){)()rts  two  or  three  cusps  the 
buccal,  which  is  called  the  hypocunld;  the  disto-huccal,  the  liypoconu- 
lid;  aud  the  disto-lingual,  the  cntucuidd.  Sometimes  there  is  developed 
on  the  liiiji^ual  face  of  the  upper  molar  a  fifth  cusp  which  is  called  the 
hypoconule.  This  is  the  counterpart  of  the  fifth  cusp  of  the  lower  molar, 
the  hypoconulid.  This  is  the  phylogenetic  history  of  the  molars  in  man, 
which  are  quite  primitive  in  type,  but  their  evolution  can  be  readily 
traced  in  beautiful  completeness. 


A 


Fig.   1 
•  •  •  • 

o     o     o     o 


-#  •- 


VqVqV 


The  phylogenetic  history  of  the  molar  cusps:  A,  the  single  cone,  the  reptilian  stage;  B.  lower 
mammals,  the  triconodont  crown;  C,  the  tritubercular  molar,  the  trigonodont  crown;  D,  the  quadri- 
tubercular  molar  crown. 

The  Dental  Arch. — The  teeth  of  man  are  arranged  around  the  margins 
of  the  upper  and  lower  jaws  in  close  contact,  and  have  no  interspaces 
between  them.  The  basal  arch  is  a  graceful  parabolic  curve,  with  some 
variations  which  lead  from  the  round  arch  to  the  incomplete  parallel- 
ogram or  even  to  a  well-defined  V-shape.  These  variations  may  be 
classified  as  follows: 

First:  The  Square  Arch  (Fig.  2,  a).  This  is  found  usually  in  persons 
of  strong  osseous  organization,  of  Scotch  or  Irish  descent — i.  e.,  of  Gaelic 
extraction — and  is  probably  derived  in  the  first  instance  from  a  doli- 
chocephalic people.  The  squareness  is  more  or  less  dependent  upon  the 
prominence  of  the  large  canines,  which  stand  out  very  markedly  at  the 


20  HUMAN  ODONTOdHAl'llY 

anjrles  of  (ho  scjiuire.  'i'lie  incisors  prt'snit  a  Hat  front  and  j)r()j{'ct  sli(^rli(lv, 
witii  little  or  no  curve  of  the  incisive  line.  The  bicuspids  and  molars 
fall  backward  from  the  canines  with  no  perceptible  curve.  The  two 
sides  are  quite  parallel,  but  sometimes  there  may  be  a  shVht  diver<rence 
toward  the  cheek  at  the  rear.  This  is  the  low  form  of  arch  wliicli  appears 
in  the  apes  and  some  low  races. 

Second:  The  Rounded  Square  (Fi<r-  2,  b).  This  is  the  medium  arch, 
and  is  the  form  usually  met  with  in  ordinary,  well-developed,  robust 
Americans.  The  canines  seem  to  be  only  sufficiently  prominent  to  give 
character  to  the  arch  without  a  resemblance  to  the  arches  of  the  lower 
animals.  The  incisors  are  vertical  and  the  line  curves  slightly  from 
one  canine  to  the  other.  The  bicuspid-and-molar  line  curves  slightly 
outward  from  the  canine  and  converges  at  the  rear. 

Fig.  2 


Square.  Rounded  Square.  Rounded.  Rounded   V. 

The  main  types  of  the  dental  arch. 

Third:  The  Rounded  Arch  (Fig.  2,  c).  This  is  the  circular  or  "horse- 
shoe" arch.  It  is  nearly  semicircular,  the  ends  curving  inward  at  the 
rear,  the  outlines  of  the  arch  tracing  a  decided  horseshoe  shape.  The 
canines  are  reduced  to  the  level  of  the  arch,  so  that  there  is  no  prominence 
of  these  teeth.  The  bicuspids  and  molars  follow  the  line  of  the  curve. 
This  arch  is  (juite  characteristic  in  some  races,  as  the  brachycephalic 
South  Germans. 

Fourth:  The  Rounded  V  (Fig.  2,  d).  In  this  form  the  round  arch  is 
constricted  in  front  or  narrowed  so  that  the  incisors  mark  a  small  curve 
whose  apex  is  the  centre.  It  is  the  arch  of  beauty,  and  is  that  most 
admired  in  women  of  the  Latin  races. 

These  are  but  the  basal  forms  of  the  dental  arch.  Ordinarily,  modi- 
fications of  these  types  occur  in  all  degrees;  it  is  the  variations,  the  com- 
posites, which  are  most  met  with. 

The  Occlusion  of  the  Teeth. — The  upper  teeth  describe  the  segment 
of  a  circle  larger  than  that  of  the  lower  teeth;  so  that  the  edges  of 
the  anterior  teeth  al)ove  close  over  those  below,  and  the  buccal  cusps 
of  the  grinding  teeth  above  close  outside  of  the  buccal  cusps  of  the  lower 
teeth  (F^ig.  3).  By  this  arrangement  the  buccal  cusps  of  the  lower 
grinders  are  received  into  the  depressions  or  sulci  between  the  buccal 
and  lingual  rows  of  the  cusj)s  and  tubercles  of  the  superior  molars  and 


Till']  OCCLUSION  OF  THE  TKETII 


21 


bicuspids,  and  the  lingual  cusps  of  llic  upper  grinders  are  received  into 
the  sulci  of  the  lower  grinders.  By  this  arrangement  the  whole  of  the 
niorsal  surfaces  of  these  teeth  are  brought  into  contact  in  the  several 
niovemeuts  of  mastication,  thereby  rendering  Uie  performance  of  tliis 
function  more  effective. 

Then,  again,  tiie  upper  incisors  usually  close  over  the  lower  for  one- 
third  of  their  length.  This  allows  of  the  shearing  action  by  which  the 
incisive  function  is  performed  as  the  edges  of  these  teeth  are  drawn  past 
each  other. 

The  line  of  the  horizon  of  occlusion  (Fig.  4,  A  to  B)  presents  a  decided 
curve  from  front  to  rear,  of  greater  or  less  degree  in  different  forms 
of  die  arch.  Thus  it  is  high  at  the  incisors,  curving  downward  at  the 
bicuspids,  reaching  its  lowest  point  at  the  first  molar;  it  curves  upward 


Fig.  3 


Fig.  4 


Incisors.     Bicuspids.         Molars. 

The  relative  position  of  the  upper  and 
lower  teeth  in  occlusion. 


The  horizon  of  the  line  of  ooflusion  and  plane  of 
occlusion. 


rapidly  at  the  second  molar,  and  is  highest  again  at  the  third.  In 
the  round  arch  the  plane  is  more  flattened  and  exhibits  the  extreme 
downward  curve  in  the  square  arch.  Between  these  extremes  there 
is,  of  course,  every  variety  of  modification.  The  form  of  the  plane  of 
occlusion  is  shown  in  Fig.  4,  C. 

The  tendency  of  the  bolus  of  food  is  toward  the  lowest  part  of  the 
curve  at  the  region  of  the  lower  first  molar,  so  that  the  extraction  of 
this  tooth  always  affects  the  performance  of  mastication. 

In  the  apposition  of  the  teeth  of  the  opposite  jaws  the  mechanical 
arrangement  is  such  that  the  dynamics  of  mastication  is  subserved 
and  the  greatest  effectiveness  secured  (Fig.  5).  Thus  the  morsal  sur- 
face of  the  upper  central  incisor  is  opposed  to  all  of  that  of  the  central 
incisor  below  and  to  the  mesial  half  of  the  lateral;  the  upper  lateral 


22 


HUMAN  ODONTOGRAPHY 


opposes  the  distal  lialf  of  the  hiteral  l)elow  and  tlie  mesial  face  of  the 
canine;  the  upper  canine,  the  distal  half  of  the  face  of  the  lower  canine 
and  the  mesial  half  of  the  first  bicuspid;  the  upper  first  bicuspid  opposes 
the  distal  half  of  the  lower  first  bicuspid  and  the  mesial  half  of  the  sec(Mid; 
the  upj)er  second  bicuspid  opposes  the  distal  half  of  the  lower  second 
bicuspid  and  part  of  the  lower  first  molar;  the  upper  first  molar  opposes 
the  distal  part  of  the  lower  first  molar  and  the  mesial  half  of  the  second; 
the  upj)er  second  molar  opposes  the  distal  half  of  the  lower  second  and 
part  of  the  third;  and  the  upper  third  covers  the  remainder  of  the  lower 
third  molar. 


Fig.  5 


The  apposition  of  the  upper  and  lower  teeth. 

By  this  method  of  apposition  the  teeth  are  so  arranged  that  two  teeth 
receive  die  impact  of  half  of  two  of  the  opposite  jaw,  thus  distributing 
the  force  of  occlusion  and  insuring  the  safety  and  strength  of  the  teeth. 
This  "break-joint"  arrangement  permits  each  tooth  to  bear  two  oppos- 
ing ones,  and  also  helps  to  preserve  the  alignment.  Then  again  if  one 
tooth  be  lost  the  opposing  teeth  still  rest  against  two  teeth,  one  at  each 
side  of  the  space.  The  normal  condition  of  the  articulation  is  rarely 
preserved,  however,  as  nuitilation  usually  disturl)S  it;  the  teeth  move  on 
account  of  the  force  of  occlusion,  and  effective  mastication  is  more  or 
less  destroyed. 

Number  and  Classes  of  the  Teeth. — Man  has  thirty-two  teeth,  divided 
into  four  classes,  viz.:  (1)  Incisors;  (2)  canines,  or  cuspids;  (3)  pre- 
molars,  or  bicuspids;  and  (4)  molars  (Fig.  6).  This  is  expressed  by  the 
dental  formula  as  follows: 


9 0 


2  —  2 


1  —  1 


',  ,,!.  2 


2 2 


2  3 

VI.    — 


3 


=  32. 


THE  INCISORS 


23 


1.  The  incisors  are  eight  in  niinil)er,  four  aViove  and  four  below — 
two  on  each  side  of  the  median  hne.  The  two  next  to  the  median  Hne 
are  called  the  central  inciaors,  the  ones  next  to  them  distally  the  lateral 
iiicisors. 

2.  The  canines,  or  cuspids,  are  four  in  number,  two  above  and  two 
below — one  on  each  sitle  innnediately  approximating  the  lateral  incisor 
on  the  distal  side. 

3.  The  premolars,  or  bicuspids,  are  eight  in  number,  four  above  and 
four  below — two  on  each  side  approximating  the  cuspids  on  the  distal 
side.  The  first  of  these  next  the  cuspid  is  called  the  first  bicuspid,  the  one 
next  to  it  on  the  distal  side  the  second  bicuspid.  The  same  designation 
applies  to  both  upper  and  lower  bicuspids. 


Fig.  6 


Incisors.     Canines  or  Premolars  or  Molars, 

cuspids.      Bicuspids. 
The  classes  of  the  teeth,  comprising  the  left  half  of  a  full  denture. 

4.  The  molars  are  tw^elve  in  number,  three  on  each  side  of  each  jaw, 
approximating  the  second  bicuspid  on  the  distal  side.  The  molar  next  to 
the  second  bicuspid,  both  above  and  below^.  is  called  the  first  molar;  the 
next  one  distally  is  called  the  second  molar;  the  next  one  distally,  and  the 
last  tooth  in  the  jaw,  is  called  the  third  molar,  or  "wasdom  tooth"  (detis 
sapientias) . 

Functionally,  the  incisors  are  formed  for  cutting,  as  their  name  im- 
plies; the  cuspids  for  prehension  and  tearing  (for  w^hich  purpose  this 
tooth  in  lower  animal  forms  is  often  excessively  developed).  It  also 
serves  in  guiding  the  bite.  The  bicuspids  are  the  crushing  teeth,  and 
the  molars  are  formed  for  grinding,  triturating,  and  insalivating  the  food. 

The  Incisors. — ^The  function  of  cutting  and  dividing  food  is  per- 
formed by  various  organs  throughout  the  animal  kingdom,  and  even 


24  HUM  AX  uDoxrudiiAPiiy 

cutting  teeth  are  founrl  verv  low  down  in  the  .scale  of  life.  The  cephalo- 
pods  have  cutting-  teetii  on  the  odontophore;  the  insects,  some  worms,  as 
the  leech  and  other  low  forms,  cut  by  means  of  sharp  or  saw-edged  man- 
dibles; in  the  sea  urchins  true  incisor  teeth  are  found  which  simulate  the 
incisors  of  rodents.  The  fishes  and  reptiles  have  no  true  incisors.  How- 
ever, in  the  fish  sargus,  incisor-like  teeth  are  found,  and  the  turtles  have 
the  jaws  sheathed  in  a  horny  covering  with  sharp  edges.  Some  aberrant 
fossil  reptiles  have  cutting  teeth  also,  but  these  are  exceptions  to  the  rule. 
The  lowest  mammals  are  deficient  in  cutting  teeth,  but  have  simple 
conical  teeth  in  all  positions  in  the  mouth,  like  the  reptiles.  The  her- 
bivora  have  highly  developed  incisors  in  all  species.  In  the  carnivora  the 
incisors  are  much  reduced,  as  their  function  is  usurped  by  the  premolars, 
which  have  long  blades  for  cutting  flesh.  In  the  quadrumana  the  human 
type  of  incisor  appears  and  develops  progressively  from  the  lemurs  to 
the  higher  apes,  in  whom  the  human  type  is  well  developed. 

The  Upper  Central  Incisor. — This  is  the  first  tooth  in  the  dental  series 
in  man.  It  is  situated  in  the  front  of  the  mouth,  next  to  the  centre  of  the 
arch,  which  is  the  mesial  border  of  the  intermaxillary  bone.  In  adult 
man  these  bones  fuse  with  the  anterior  borders  of  the  right  and  left 
superior  maxillary  bones.  Their  junction  with  each  other  marks  the 
centre  of  the  dental  arch. 

The  general  form  is  that  of  a  truncated  cone  with  its  top  flattened  out 
to  form  the  cutting  edge. 

The  form  of  the  crown  is  spade-like,  or  a  compressed-wedge  shape, 
the  edge  being  quite  thin  and  the  thickness  increasing  rapidly  to  the 
base.  It  is  slightly  bent  toward  the  lingual  side,  or  much  curled  over  in 
some  cases. 

The  labial  face  is  imperfectly  scjuare  or  oblong,  the  cervical  margin 
being  rounded  (P'ig.  10,  a).  It  is  convex  from  side  to  side,  but  only 
slightly  so  from  cervix  to  edge.  Two  shallow  depressions  or  furrows 
extend  the  length  of  the  face  perpendicularly  (b),  dividing  it  into  thirds, 
called  lobes — the  mesial,  (c),  median  {d),  and  distal  lobes  (e).  These 
furrows  and  lobes  are  quite  conspicuous  when  the  tooth  is  erupted,  but 
are  abraded  by  age  and  the  wear  of  use  and  dentifrices,  until  the  face 
becomes  smooth.  The  mesial  margin  is  a  little  longer  than  the  distal,  so 
that  the  cutting  edges  slope  upward  toward  the  distal  side  (/). 

The  lingual  face  is  smaller  than  the  labial,  being  on  the  inner  and 
smaller  curve  of  the  crown,  and  is  narrower  from  side  to  side  (Fig.  7). 
It  is  triangular  in  outline,  being  wide  at  the  edge  and  narrow  and  rounded 
at  the  base  or  cervix.  The  marginal  ridges  (a)  are  high  and  conspicuous, 
and  extend  from  the  basal  ridge  to  the  edge  on  the  mesial  and  distal  mar- 
gins of  this  surface.  The  basal  ridge  (b)  is  a  strong  elevation  continuous 
with  the  marginal  ridges  at  the  base  of  the  crown.  It  is  sometimes 
developed  into  a  raised  cusp,  the  ridge  at  the  base  of  which  forms  a  cingu- 
lum.    A  ridge  or  lobe  (c)  extends  from  the  basal  ridge  to  the  centre  of  the 


THE  UPPER  CENTRAL  INCISOR 


25 


edge,  uniting  with  the  median  lobe  from  the  lahial  face  to  form  the 
median  tubercle.  A  depression  or  fossa  [d)  is  found  on  each  side  of  the 
me(h'an  lobe  between  it  and  the  marginal  ridges,  or,  when  the  lobe  is  low 
or  entn-ely  absent,  these  fossa'  may  be  continuous.  A  fuidl,  or  Jls-sure,  at 
its  junction  with  the  basal  ridge  frequently  forms  the  seat  of  caries. 

The  mc.sud  face  (Fig.  8)  is  a  rather  long  triangle  in  shape,  with  a 
concaved  base  at  the  cervix  of  the  tooth  (r/)  and  a  long  point  toward  the 
edge.  It  is  nearly  straight  in  a  longitudinal  direction,  but  rounded  and 
convex  transversely.  It  is  longer  than  the  distal  face,  the  edge  descend- 
ing in  that  direction.  The  ena^nel  line  dips  downward  into  this  face,  and 
there  is  a  depression  above  it  {h)  which  sometimes  extends  upward  on  the 
root.    The  point  of  contact  with  the  opposing  tooth  is  near  the  cutting 


edge. 


Fig.  8 


c 
Diagram  of  the  lingual  face  of  the  upper 
central  incisor. 


Mesial.        Distal.  9 

The  mesial  and  distal  faces  and  edge  of  the 
upper  central  incisor. 


The  distal  face  is  also  triangular  in  outline  (Fig.  8),  but  it  is  more 
curved  in  the  longitudinal  axis,  so  that  this  surface  is  convex  in  all  direc- 
tions. It  is  most  curved  in  the  transverse  direction.  The  enamel  dips 
downward  into  the  surface  (d),  as  in  the  mesial,  but  there  is  not  so  much 
of  a  depression  above  this  hne.  The  point  of  contact  is  one-third  of  the 
distance  from  the  angle  (e). 

The  edge,  or  morscd  margin,  of  the  crown  is  formed  by  the  compression 
of  the  top  of  the  truncated  primitive  cone.  It  is  quite  wide  and  square 
except  at  the  distal  corner,  which  is  rounded.  The  angle  with  the  mesial 
face  is  acute  (Fig.  8,  /).  When  the  tooth  is  first  erupted,  the  edge  has 
three  prominent  tubercles  (g),  which  correspond  to  the  ridges  on  the 
labial  and  lingual  faces.  These  are  soon  worn  off  with  use,  so  that  the 
edge  usually  looks  straight.  The  pitch  of  the  edge  is  toward  the  median 
line. 

The  mechanical  structure  of  the  crown  is  a  matter  of  importance.  It 
will  be  observed  that  it  consists  of  several  elements :  first,  a  broad  cutting 
blade  (Fig.  9,  n)  supported  by  two  strong  lateral  columns  (b)  on  each 
side,  and  that  these  columns  are  upheld  by  two  strong  marginal  ridges 
(c)  leading  up  from  the  lower  ridge  (rf).  These  ridges  are  buttresses 
which  guy  and  uphold  the  columns  which  contain  and  carry  the  blade. 
Hence,  when  these  ridges  are  destroyed  by  caries  or  in  operating  the 
support  of  the  column  is  lost  and  the  blade  readily  breaks  away. 


26 


HUMAN  ODONTOGRA/'HV 


Tn  operations  upon  this  tooth,  this  bhule-hke  structure  must  he  con- 
stantly borne  in  mind,  for  weakening  of  the  elements  of  the  crown  may 
easily  result  from  excessive  cutting.  The  colunuis  of  support  can  he  better 
preserved  with  the  inlay  filling  than  with  pressure  fillings  which  recjuire 
more  strength  of  walls.  Less  cutting  away  is  recjuired,  and  the  contour 
can  be  better  preserved  and  supported  l)y  the  inlay  and  cement.  A 
better  esthetic  effect  is  also  thereby  obtained.  Small  cavities  in  these 
teeth  are,  of  course,  better  filled  with  pressure  gold  fillings,  but  larger 
ones  are  better  treated  by  fillings  with  porcelain  inlays,  care  being  taken 
to  preserve  as  much  tooth  substance  as  possible,  to  attain  the  best  artis- 
tic and  mechanical  results.  P>agile  enamel  margins  should  not  be 
retained,  of  course,  but  when  backed  l>y  dentine  the  walls  should  be 
preserved — especially  when  parts  of  the  supporting  columns  of  the 
crown. 

Fig.  9  Fig.  10 

d  ■  ^ 


The  mechanical  design  of  the  crown  of  the 
upper  central  incisor:  a,  the  blade;  b,  the  two 
columns  supporting  the  blade;  c,  the  marginal 
ridges  acting  as  guys,  bracing  the  columns; 
d,  the  basal  ridge  at  the  base  of  attachment 
for  the  guys. 


Diagram  of  the  labial  face  of  the  upper 
central  incisor. 


The  neck  of  the  central  incisor  is  a  rounded  pear-shape  in  outline, 
the  labial  half  being  wider  (Fig.  11,  a)  than  the  lingual.  There  is  not 
much  constriction  of  the  tooth  at  the  neck.  The  enamel  edge  curves 
upward  on  the  root  on  the  laliial  and  lingual  sides,  and  dips  downward 
on  the  mesial  and  distal  faces.  It  terminates  abruptly  on  all  sides, 
especially  on  the  lingual,  where  a  considerable  ridge  is  sometimes  raised 
(Fig.  10,  c). 

The  root  is  cone-shaped  and  tapering  (Fig.  11,  ^).  The  rounded  pear- 
shaped  section  continues  almost  to  the  end. 

The  pulp  chamber  is  spacious  and  open,  and  of  the  general  form  of 
the  tooth  (a  and  c).  The  radical  portion  of  the  canal  gives  free  access, 
but  the  flattened  coronal  portion  is  difficult  to  clean.se.  In  young  teeth 
the  cornua  or  horns  of  the  pulp  may  project  far  toward  the  angles  (c). 

The  Lateral  Incisor. — This  tooth  approximates  the  central  incisor  on 
its  distal  side,  and  is  also  implanted  in  the  intermaxillary  bone.  It  is 
of  similar  spade-like  form  and  of  the  same  architectural  design  as  the 


77/ A'  LATIJRAL  INC  ISO  Ji 


27 


central,  modified  by  the  distal  half  heiiio'  more  louiided  in  every  direc- 
tion. As  the  crown  is  narrower  than  the  central,  the  destruction  of  the 
marginal  ridges  on  the  lingual  face  weakens  the  edge  still  more,  so  that 
it  breaks  off  more  easily.  The  crown  is  narrower  in  the  mesio-distal 
diameter  than  the  central,  but,  still  almost  as  wide  labio-lingually,  the 
relative  difference  of  thickness  in  the  two  directions  is  more  apparent. 
The  tooth  has  the  appearance  of  being  compressed  mesio-distally.  The 
thickness  increases  rapidly  from  the  edge  to  the  neck  (Fig.  12,  B). 


Fig.  11 


Fig.  12 


.d      E 


The  root  of  the  upper  central  incisor. 


3-^A  B  C  D 

Tlie  upper  lateral  incisor. 


The  lahlal  face  (Fig.  12,  C)  is  more  rounded  than  that  of  the  central. 
It  is  half  incisor  and  half  cuspid  («),  the  mesial  half  toward  the  central 
incisor  resembling  that  tooth  (h),  and  the  distal  half  toward  the  cuspid 
resembling  it  (c).  The  mesial  angle  of  the  edge  is  quite  acute,  while  the 
distal  ang-le  is  rounded  and  obtuse.  The  three  lobes  may  be  well  devel- 
oped, similar  to  those  on  the  central  incisor,  but 
are  usually  indistinct,  although  the  central  ridge 
is  prominent. 

The  lingual  face  (Fig.  12,  D)  is  much  de- 
pressed, but  less  concave  than  that  of  the  central 
incisor.  The  marginal  (d)  and  basal  ridges  (e)  are 
quite  prominent.  The  basal  ridge  is  often  raised 
into  a  permanent  cingule  or  talon,  an  exaggerated 
example  of  which  is  shown  in  Fig.  13,  which  is  a 
revival  of  the  basal  talon  found  in  the  apes — and 
the  insectivora.  This  cingule  occurs  more  fre- 
quently on  the  lateral  incisor  than  on  any  other 
of  the  anterior  teeth.  The  depression  above  it  is 
often  the  location  of  a  fault,  a  fissure  or  pit,  which 
becomes  the  seat  of  caries.     The  basal  ridge  is 

sometimes  cut  by  a  fissure  which  leads  down  quite  upon  the  neck  of 
the  tooth  (Fig.  12,  /).  Sometimes  the  entire  surface  is  full  and  rounded 
without  any  concavity  whatever. 

The  mesial  face  (g)  is  of  triangular  form  similar  to  that  of  the  central 
incisor.  It  is  rounded  toward  the  edge  labio-lingually,  but  flattened  at 
the  neck,  with  a  depression  at  the  enamel  line  which  leads  upward  upon 


Showing  unusual  devel- 
opment of  the  cingule  or 
basal  talon  on  an  incisor. 
(From  case  reported  by  Dr. 
W.  H.  Mitchell,  Dental 
Cosmos,  vol.  xxxiv.  p. 
1036.) 


28  II UMAX   ODOSTUaUM'IIY 

the  root.  The  labial  an^le  is  sometimes  the  seat  of  a  depression  (A), 
which  u;ives  the  angle  a  hook  shape.  The  depression  varies  in  width  and 
depth,  and  may  become  the  seat  of  caries.  The  point  of  contact  with 
the  central  incisor  is  at  the  junction  of  the  lower  with  the  middle  third 
of  the  length  of  the  face. 

The  distal  jace  is  more  convex  in  all  directions,  and  reseml)les  the 
canine  in  form,  being  in  harmony  with  the  general  form  of  the  distal 
half  of  that  tooth.  From  cervix  to  edge  it  is  rounded  and  the  contact 
eminence  in  the  middle  third  is  very  full  (/).  From  this  point  it  rounds 
off  rapidly  to  the  edge.  The  upper  third  is  depressed  rapidly  toward 
the  cervix,  with  a  considerable  depression  at  the  enamel  litie  leading 
off  to  the  distal  groove  on  the  root. 

The  edxje  is  divided  into  two  portions  by  the  prominent  tubercle  (y) 
in  the  middle  which  terminates  the  prominent  central  ridge  of  the  labial 
face.  The  mesial  half  is  straight,  like  that  of  the  central.  When  worn, 
these  features  disappear  and  the  edge  becomes  almost  straight.  The 
pitch  of  the  edge,  like  that  of  the  central,  is  toward  the  median  line. 

The  same  mechanical  structure  of  the  crown  is  found  in  the  lateral 
as  in  the  central,  except  that  the  crown  is  more  slender  and  weaker,  so 
more  precaution  must  be  observed  to  prevent  breaking  during  and 
after  operating  upon  it. 

The  neck  is  much  flattened  mesio-distally,  and  is  of  a  compressed 
pear  shape,  or  flattened  oval  on  section.  The  enamel  margin  pursues 
the  same  course  as  on  the  central  incisor,  rounding  upward  toward  the 
root  on  the  labial  and  lingual  sides  and  dipping  downward  on  the  distal 
and  mesial.  It  does  not  terminate  so  abruptly  as  that  of  the  central 
incisor,  and  presents  less  of  a  ridge  at  the  gingival  margin. 

The  rooi  is  commonly  longer  than  that  of  the  central  incisor,  is  nar- 
rower, flattened  mesio-distally  (Fig.  12,  A,  B).  It  tapers  gradually,  not 
rapidly  like  the  root  of  the  central  incisor.  It  is  a  flattened  oval  on 
section  (E).  Sometimes  there  is  a  hook  at  the  end,  curved  distally. 
(Grooves  sometimes  occur  on  the  mesial  and  distal  sides. 

The  pulp  canal  is  flattened  in  conformity  to  the  shape  of  the  root, 
but  is  readily  entered  if  the  root  ])e  straight. 

The  lateral  incisor  is  very  irregular  as  to  form,  presenting  various 
degrees  of  deformity  or  abnormality,  and  may  sometimes  be  reduced  to 
a  mere  peg.  It  is  also  erratic  as  to  eruption,  being  sometimes  suppressed, 
not  appearing  for  several  generations  of  a  family.  It  follows  the  third 
molar  in  the  frequency  of  its  irregularities  both  as  to  form  and  frecpiency 
of  non-eruption. 

The  third  incisor  of  the  primitive  typal  mammal  sometimes  reappears 
in  man,  and  is  known  as  a  supernumerary.  It  rarely  assumes  the  proper 
incisor  form  and  position  in  the  arch,  but  usually  erupts  within  the 
arch,  and  is  a  mere  pointed  peg-shapetl  tooth. 


THE  LOW  EH  INCLSOltS 


29 


The  lower  incisor. 


The  Lower  Incisors. — These  are  most  conveniently  described  as  a  group, 
as  they  are  very  similar  in  form,  having  but  slight  variations  between 
the  central  and  lateral  incisors  to  be  noted. 

They  are  located  in  the  anterior  portion  of  the  lower  jaw,  upon  each 
side  of  the  median  line,  opposite  the  incisors  above.  Their  function  is 
the  same  as  that  of  the  upper  incisors,  the  cutting  of  food,  which  they 
perform  by  opposing  the  upper.  The  lower  central  opposes  only  the 
central  above;  the  lateral,  both  the  upper  central  and  lateral  incisors. 

The  lower  central  incisor  is  the  smallest  tooth  in  the  dental  series.  It 
is  ()f  spade-like  form  (Fig.  14),  the  crown  being  a  double  wedge  shape 
(a,  /;).  The  first  wedge  (a)  is  observed 
on  viewing  the  crown  from  the  front, 
the  widest  portion  being  at  the  morsal 
edge  and  the  point  at  the  cervix.  The 
second  wedge  is  observed  from  the 
side  (b),  the  widest  part  being  at  the 
neck  and  the  point  at  the  morsal  edge 
of  the  crown.  The  edge  is  thin,  but 
the  labio-lingual  diameter  increases 
rapidly    to    the   cervix,   which   is    the 

widest  part.  The  crown  is  widest  mesio-distally  at  the  edge,  but  dimin- 
ishes to  the  neck,  which  is  scarcely  more  than  half  the  width  of  the  edge. 
The  tooth  cone  is  therefore  compressed  in  one  direction  at  the  edge, 
and  in  another  at  the  cervix.  The  mechanical  elements  are  the  same 
as  those  of  the  upper  central,  but  with  the  parts  less  strongl}'  marked. 

The  labial  face  is  a  long  wedge  shape  (a),  the  widest  part  at  the  edge 
and  narrowing  to  the  cervix.  It  is  usually  straight,  or  nearly  so,  longi- 
tudinally, and  straight  across  the  edge,  but  round  and  convex  at  the 
neck  and  the  cervical  half.  Sometimes  vertical  ridges  are  found  on  these 
teeth  when  they  are  first  erupted,  but  these  soon  wear  off. 

The  lingual  face  is  depressed  and  concave  from  edge  to  cervix  (c), 
but  less  so  from  side  to  side.  The  marginal  ridges  are  often  well  marked. 
In  the  lateral  incisor  the  fossa  is  often  more  marked  and  the  marginal 
ridges  more  distinct. 

The  mesial  and  distal  sides  are  of  wedge-like  form,  straight  from  edge 
to  cervix  and  widening  in  the  same  direction.  A  depression  runs  across 
the  neck  just  above  the  enamel  line. 

The  neck  is  much  compressed  disto-mesially,  and  the  root  partakes 
of  this  flattening  through  its  entire  length.  The  section  presents  a 
compressed  oval  (e),  The  enamel  line  dips  downward  on  the  labial  and 
lingual  sides,  and  curves  upward  on  the  mesial  and  distal  in  a  manner 
characteristic  of  the  incisors. 

The  edge  is  perfectly  straight  from  side  to  side,  after  the  three  tuber- 
cles, found  when  first  erupted,  are  worn  off. 

The  root  is  flattened  like  the  neck,  and  frequently  a  groove  runs  the 


30  HUMAN  ODOATOGRAJ'in- 

entire  length  on  the  mesial  and  di.stal  sides.  Oeeasionallv  conijjlete 
hifnreation  resuhs,  wiiieli  recalls  the  form  of  this  tooth  tonnd  in  lower 
animals. 

The  pulp  canal  [c)  is  of  similar  form  to  the  root,  and  is  flattened  and 
thin,  so  that  it  is  often  difheult  to  effect  an  entrance  to  it  with  instru- 
ments. 

The  lateral  incisor  is  similar  in  form  to  the  central  incisor,  hut  is  wider 
at  the  edge,  and  the  distal  corner  of  the  edge  is  slightly  rounded  {(I).  In 
all  other  features  it  resemhdes  the  central  incisor. 

The  canine,  or  cuspid,  appears  very  early  in  the  history  of  vertel)rate 
life  in  its  prototype,  the  single  conical  tooth  of  fishes  and  reptiles.  The 
conical  form  of  the  canine  is  maintained  down  through  all  the  suc- 
ceeding stages  to  man,  with  mere  variations  as  to  contour,  as  manifested 
in  the  higher  vertebrates.  It  is  the  tooth  of  prehension  from  the  lowest 
to  the  highest  forms.  As  prehension  is  the  most  primitive  of  tooth  func- 
tions, so  the  conical,  canine  tooth  is  the  primitive  tooth.  In  the  higher 
mammals  it  is  probably  modified  from  the  premolar  series,  as  it  is  the 
first  tooth  posterior  to  the  intermaxillary  suture.  In  the  lower  mammals 
it  is  variously  modified,  but  it  is  in  the  carnivora  that  it  attains  its 
highest  specialization.  Its  greatest  development  was  found  in  the 
extinct  felidse,  where  it  was  long  and  sabre-shaped,  with  sharp 
serrated  edges,  as  in  the  cave  lion  and  bear  and  the  fossil  forms  of 
America.  The  living  cats,  the  lion,  tiger,  leopard,  etc.,  have  the  highest 
forms  of  this  tooth,  but  it  is  reduced  in  the  dogs  and  bears  and  other 
omnivorous  forms.  In  the  quadrumana  the  canines  are  well  developed, 
and  in  the  apes  they  are  very  large  and  strong,  and  are  formidable  weap- 
ons. Owing  to  the  continued  absence  of  the  "missing  link,"  there  is  a 
sudden  transition  between  the  higher  apes  and  man,  as  they  are  much 
reduced  in  the  latter,  being  brought  down  to  the  level  of  the  other  teeth. 
Indeed,  the  canine  presents  more  points  of  divergence  from  the  form  of 
this  tooth  in  the  anthropoid  apes  than  any  of  the  other  teeth,  all  of  which 
resemble  those  of  the  apes  very  closely.  It  is  practically  a  crushing 
tooth  in  man  as  prehension  is  in  abeyance  as  a  human  dental  function. 

The  Upper  Cuspid. — This  is  the  third  tooth  from  the  median  line, 
and  approximates  the  lateral  incisor  on  its  distal  side.  It  is  the  first 
tooth  posterior  to  the  intermaxillary  suture,  and  is  embedded  in 
the  maxilla  proper.  It  is  commonly  said  to  form  the  spring  of  the 
arch,  and  conveys  the  impression  of  great  strength,  as  is  indicated  by 
its  strong  implantation.  It  is  more  strongly  implanted,  and  l)y  a  longer 
and  larger  root,  than  any  of  the  other  teeth.  Zoologically  it  is  the  largest 
tooth  in  the  dental  series,  but  in  man  is  much  reduced  from  its  proto- 
type, the  larger  carnassial  canine  of  lower  animals,  especially  the  car- 
nivora. It  is  the  principal  prehensile  tooth,  and  is  therefore  first  in 
order  of  function  in  the  dental  series. 

The  crown  has  a  spear-head  shape  (&),  hence  its  name,  cuspid,  from 


THE  UPPEli  CUSPID 


31 


the  Latin  cv.spis,  "point,  pointed  end."  It  is  constructed  essentially 
for  piercing  and  tearing.  The  central  cusp  or  point  is  braced  in  all 
directions;  the  edges  leading  up  to  it  both  mesially  and  distally  (which 
serve  for  cutting  as  well),  the  strong  labial  ridge  coming  downward 
from  the  cervix  (c)  to  the  median  ridge  leading  up  on  the  lingual  sur- 
face (rf),  all  support  it  in  the  office  of  prehension  and  the  laceration 
of  flesh. 

The  labial  face  (b)  presents  the  outlines  of  the  spear  shape,  more  or 
less  rounded  in  different  cases.  Starting  from  the  well-defined  cusp  just 
in  front  of  the  central  axis  of  the  tooth,  it  widens  sharply  for  about  one- 
third  of  its  length,  whence  it  narrows  gradually  to  the  gum  line,  w^hich 
is  fully  rounded.  In  some  cases  the  mesial  and  distal  angles  are  rounded 
and  the  outlines  are  more  of  a  leaf  shape  (e).  The  surface  is  slightly 
rounded  mesio-distally,  so  that  the  sides  slope  roundly  or  flatly  away 
from  the  central  ridge.  This  ridge  descends  from  the  middle  of  the 
cervical  margin,  curving  slightly  forward  and  then  backward  to  the 


Fig.  15 


c  d  e 

The  upper  cuspid. 


point  of  the  cusp  (c).  This  curve  recalls  the  curving  shape  of  this  tooth 
in  the  felidse.  It  is  usually  a  sharp,  prominent  ridge,  but  may  be  re- 
duced and  rounded  so  as  to  be  scarcely  perceptible.  The  three  lobes 
of  the  surface  are  imperfectly  marked — the  central  ridge  dominating 
and  dwarfing  the  lateral  ones.  The  lateral  furrows  on  each  side  of 
the  central  ridge  separating  it  from  the  lateral  lobes  are  more  or  less 
marked,  especially  toward  the  edge.  Wear  reduces  in  time  the  promi- 
nence of  the  lobes  and  ridges  and  obliterates  the  furrows. 

The  lingual  face  is  of  similar  spear-shape  (cT),  but  is  more  flat.  It  is  rarely 
concave.  The  thickness  of  the  crown  increases  gradually  to  the  lateral 
prominences,  which  gives  a  blade-like  edge,  then  rapidly  to  the  shoulder 
at  the  base.  A  strong  vertical  ridge  extends  from  the  cusp  to  the  basal 
ridge  (d),  with  a  slight  concave  depression  on  each  side.  The  basal 
ridge  is  well  marked  and  sometimes  develops  into  a  cingule,  more  or  less 
marked.  The  marginal  ridges  lead  up  on  each  side  only  so  far  as  the 
lateral  protuberances.     They  are  not  strongly  marked  as  a  rule.     The 


32  I/IM.W   (JDOSTOCRM'IIY 

fosste  oil  each  side  of  the  \(>rtical  median  rid^re,  between  it  and  the  mar- 
ginal ridges,  may  he  (juite  deep,  init  are  usually  shallow  and  ill  defined. 
The  me.sldl  faee  in  outline  is  not  unlike  the  central  incisr)r,  hut  its 
contotu'  is  very  diii'erent,  for  it  is  more  or  less  rounded  in  all  directions, 
and  the  lateral  eminence  in  the  lesser  third  makes  this  part  especially 
full  (/').  From  this  point  the  surface  is  depressed  roundly  to  the  eii,imel 
line  at  the  neck,  where  a  depression  of  greater  or  less  depth  is  found. 
It  is  somewhat  flattened  at  the  cervix.  The  point  of  contact  is  at  the 
eminence,  which  touches  the  lateral  incisor. 

The  distal  face  is  of  similar  form  to  the  mesial,  except  that  it  is  more 
full  and  the  eminence  more  pronounced,  which  gives  the  increased  width 
of  the  crown  on  that  side.  The  surface  descends  rapidly  toward  the  neck 
and  is  rounded  labio-lingually.  The  point  of  contact  with  the  first 
bicuspid  is  on  the  lateral  protuberance. 

The  morscd  edge  presents  a  prominent  cusp,  which  is  almost  central 
to  the  long  axis  of  the  tooth.  The  side  facets  slope  away,  but  still  retain 
their  cutting  edge  (h).  The  distal  side  of  the  edge  is  longer  than  the 
mesial,  by  reason  of  the  increased  size  of  the  distal  protui)erant  angle. 
The  sharp  point  is  soon  worn  oft'  to  a  rounded  cusp,  and,  as  wear  increases 
with  age,  it  may  be  reduced  to  a  straight  surface  between  the  mesial 
and  distal  protuberances  (r/). 

The  neck  is  a  flattened  oval  on  section,  or  the  lateral  direction  of  the 
labial  ])ortion  may  be  greater  than  tiiat  of  the  lingual  {h).  The  enamel 
line  preserves  the  same  curves  as  on  the  incisors,  /.  c,  rounding  upward 
on  the  labial  and  lingual  surfaces  and  dipping  downward  on  the  mesial 
and  distal.  The  enamel  terminates  gradually  with  but  a  slight  ridge, 
unless  it  should  be  on  the  lingual  side.  A  depression  occurs  on  both 
mesial  and  distal  sides  above  the  curve,  which  may  lead  up  as  a  groove 
on  the  root. 

The  root  is  longer  than  that  of  any  other  tooth,  and  it  is  at  least  one- 
third  larger  than  that  of  the  central  incisor.  It  is  of  a  rounded  trihedral 
form,  or  irregularly  conical.  It  is  usually  straight,  and  tapers  t(;  a 
slender  point,  which  may  be  curved  or  very  crooked.  In  well-arranged 
dentures,  where  it  has  erupted  naturally,  it  is  usually  straight. 

The  'puly  canal  is  large  and  open,  of  the  same  form  as  the  tooth,  and 
easily  entered.  It  is  regularly  formed  except  in  those  cases  where  the 
root  is  curved,  and  even  in  these  it  can  be  filled  if  not  too  crooked,  as  it 
is  so  open  and  acce.ssible. 

The  Lower  Canine. — This  is  similar  to  the  upper  in  form  and  outline, 
except  tiiat  it  is  somewhat  smaller,  more  slender,  and  uK^re  rounded  in 
form  (Fig.  16,  a).  It  differs  also  in  being  more  compressed  mesio-distally 
and  in  being  flattened  in  the  neck  and  root.  The  crown  leans  l)ackward 
on  the  root  so  that  the  mesial  face  is  almost  straight  the  entire  lengtii 
of  root  and  crown.  It  forms  the  spring  of  the  lower  arch,  and  is  strongly 
built  to  oppose  the  strong  upper  canine  in  the  act  of  prehension  and 


THE  LOWER  CANINE 


33 


Fig.  16 


teariiijj.    It  opposes  the  mesial  surface  of  the  canine  al)ove  and  the  distal 
surface  of  the  upper  lateral  incisor. 

The  Idbidl  face  is  a  long  oval  (r/),  the  cusp  beino^  hlunt  and  the  neck 
rounded  Avhile  the  mesial  side  (c)  is  flattened.  The  lobes  are  indistinct 
and  the  central  ridge  is  rounded  from  side  to  side.  The  entire  face  is  in- 
clined inwanl  to  accommodate  the  occlusion.  The  crown  in  manv  cases 
presents  the  appearance  of  being  blunt  toward  the  distal  side. 

The  Ungnul  face  [h)  is  flat,  sometimes  cup-shaped,  and  the  marginal 
ridges  are  not  prominent.  The  central  ridge  sometimes  stands  out 
strongly.  The  basal  ridge  is  weak  and  is  rarely  developed  into  a  cin- 
gule.  The  crown  increases  gradually  in  thickness  from  the  point  to  the 
neck. 

The  mnrsal  siirfdcc  presents  a  mere  rounded  eminence;  the  cusp  may 
be  sharp  in  childhood,  but  usually  it  is  soon  reduced  by  wear.     Some- 
times it  remains  sharp  and  prominent.    The  lateral  edges  are  not  devel- 
oped, but  are  mere  ridges  lead- 
ing  down   to  the   lateral   faces, 
which  are  not  prominent,  except 
the  distal  {d),  which  is  often  full. 

The  mesial  face  is  quite  flat, 
and  straight  with  that  face  of 
the  root.  The  eminence  is  not 
marked.  It  is  rounded  only  at 
the  eminence,  but  flattened  at 
the  cer\'ical  third  {c). 

The  distal  face  has  the  most 
prominent    eminence     {d),    the 

crown  being  bent  in  that  direction.    The  cervical  third  of  this  face  is  Hat. 
It  descends  rapidly  from  the  eminence. 

The  neck  is  usually  oval  (/),  or,  when  compressed,  spindle-shaped 
upon  section  {g),  being  depressed  on  the  mesial  and  distal  sides  at  the 
origin  of  the  grooves  nmning  up  on  the  root.  The  enamel  line  is  not 
so  variable  as  on  the  incisor,  but  more  nearly  on  a  level  on  all  four 
aspects. 

The  root  is  long,  flattened,  and  tapering  (a,  h,  c).  It  is  shorter  than 
that  of  the  upper  cuspid.  It  is  grooved  on  the  mesial  and  distal  sides — 
so  much  so  as  to  tend  toward  bifurcation.  This,  indeed,  sometimes 
happens  in  man,  thereby  recalling  the  form  usual  to  the  primates  and 
some  other  lower  animals. 

The  pulp  canal  is  of  the  same  general  form  as  the  root,  often  presenting 
the  spindle-shape  on  section.  It  is  somewhat  difficult  to  enter  on  account 
of  its  flattened  shape  and  narrowed  channel. 

The  canine  being  larger,  stronger,  and  more  robust  than  the  incisors, 
presents     fewer    elements    of    mechanical    weakness    of    the    crown 
than  those  teeth.     The  body  of  the  crown  is  thicker  from  the  cervix 
3 


The  lower  canine. 


34  HUMAN  ODONTOGRAPHY 

to  the  inorsal  point,  and  is  well  supported  laljially  hy  the  rounded  emi- 
nence of  this  face  and  lingually  by  the  columns  on  thai  face.  The 
median  third  of  the  erown  is  stronu;  enou<fh  for  self-support,  even  when 
the  mesial  and  distal  columns  are  destroyed,  which  is  not  the  case  with  the 
incisor  blade.  The  morsal  point  is  still  strong  enough  for  serviceable 
employment  in  food  reduction.  This  mechanical  structure  of  the  canine 
permits  of  more  extensive  operations  upon  the  mesial  and  distal  faces 
of  the  crown  than  is  possible  with  the  incisors,  This  obtains  even  with 
pressure  gold  fillings,  and  is,  of  course,  much  more  ap})lica\)le  to  inlay 
fillings.  But  the  important  fact  must  also  be  taken  into  consideration 
that  the  canine  having  been  transplanted  from  the  premolar  series, 
in  the  process  of  evolution,  is  subjected  to  much  more  stress  in  the  per- 
formance of  its  duties  in  food  reduction  than  the  incisors.  In  fact,  most 
of  the  errors  of  operating  upon  this  tooth  are  due  to  the  fact  that  it  is 
treated  as  an  incisor  rather  than  a  premolar  in  its  artificial  restoration. 
The  solidity  of  its  support,  the  deep  implantation,  the  strength  of  crown, 
all  tend  to  encourage  the  instinctive  hard  usage  which  this  tooth  receives, 
an  instinct  which  is  partly  inherited  from  the  stage  of  evolution  of  the 
species  when  it  was  a  useful  and  effective  weapon.  On  account  of  this 
hard  usage,  operations  upon  this  tooth  must  be  planned  for  the  endur- 
ance of  great  stress,  in  order  that  fewer  failures  shall  result  from  mis- 
apprehension of  its  office. 


THE  TUBERCULATE  TEETH 

The  very  lowest  forms  in  which  grinding  organs  appear  are  the  cusped 
prominences  upon  the  stomacholiths,  the  gastric  mill  of  the  Crustacea. 
The  larval  stage  of  some  insects  also  have  calcareous  grinding  organs 
in  the  stomach  or  proventriculum.  In  the  lower  vertebrates  the  crushing 
teeth  appear  first  in  the  fishes  which  have  well-developed  pavement 
teeth  for  crushing  shellfish.  True  tuberculate  teeth  do  no  appear,  how- 
ever, until  the  stage  of  the  higher  reptiles,  some  lizards  having  posterior 
tubercular  teeth,  which  are  the  forenmners  of  the  molar  teeth  of  the 
mammalia.  In  the  lower  mammals  the  crushing  and  grinding  teeth 
are  very  simple,  as  in  the  bruta,  in  which  the  crushing  teeth  are  simple 
dentin  cylinders,  worn  in  facets.  Gradual  progress  takes  place  in  the 
evolution  of  the  grinding  teeth  until  the  highly  developed  molars  of  the 
herbivora  are  attained,  on  the  one  hand,  and  the  cutting  premolars  of 
the  carnivora,  on  the  other — both  highly  developed  for  reducing  special 
kinds  of  food.  Between  these  two  extremes  are  many  intermediate 
forms,  variously  adapted  to  omnivorous  diets.  Among  these  inter- 
mediate forms  man  is  found,  whose  simple,  tuberculate  denture  is  adapted 
to  an  omnivorous  diet.  The  grinding  teeth  of  man  are  of  primitive 
bunodont  type,  which  recalls  early  geological  forms  of  molars,  harking 


THE  TUBERCULATE  TEETH 


35 


back  to  his  ancestral  prototyjx'  of  the  tertiary  formations.  The  evolu- 
tion of  the  human  molars  is  a  beautiful  study — as  has  been  previously 
illustrated. 

The  Bicuspids. — The  bicuspids  in  man  are  homologous  with  the  pre- 
molars of  the  (luadruniana  and  other  lower  mammals.  They  succeed 
and  displace  the  molars  or  grinders  of  the  deciduous  set.  They  are 
placed  next  after  the  cuspids  in  both  jaws,  and  midway  between  the 
cutting  and  grinding  teeth.  Their  function  is  the  crushing  of  food 
preparatory  to  mastication. 

The  Upper  Bicuspids. — The  upper  bicuspid  is  formed  by  duplication 
of  the  primitive  cone  and  cusp  in  a  transverse  direction  (Fig.  17,  «). 
^'iewed  from  the  standpoint  of  comparative  dental  anatomy,  the  external 
cone  is  the  canine  cone — and  to  this  is  added  the  internal  or  bicuspid  cone, 
the  tooth  being  a  double  canine.  The  bicuspids  are  the  first  of  the  com- 
plex teeth.  The  internal  cusp  is  formed  by  the  raising  of  the  inner  prim- 
itive cusp  of  the  cuspid  and  the  development  of  a  root  to  support  it.  The 
distinctive  feature  of  the  architecture,  therefore,  is  its  formation  from 
two  cones. 

The  upper  first  bicuspid  approximates  the  cuspid  on  the  distal 
side. 


Fig.  17 


Fig.  18 


The  upper  bicuspids. 

The  buccal  face  [c]  is  of  spear-head  shape,  similar  to  that  of  the  cuspid. 
This  is  more  apparent  in  some  lower  mammals  than  in  man,  in  whom  it 
is  much  reduced  and  rounded,  so  as  to  give  usually  the  appearance  of  a 
long,  rounded  oval.  The  buccal  cusp  (c)  rises  sharply  and  prominently 
from  the  lower  centre  of  the  face,  from  which  a  strong  ridge  (d)  leads  up 
to  the  cervical  border.  The  mesial  and  distal  lobes  (e,  e)  are  rarely 
conspicuous,  and  the  furrows  between  them  and  the  central  ridge  lead 
but  half-way  up  the  crown.  The  lobes  sometimes  have  prominent 
points  at  the  morsal  margins,  which  in  lower  mammals  become  pro- 
nounced cingulums.  The  buccal  marginal  ridges  descend  from  the 
points  of  the  cusp  to  the  points  of  the  lateral  lobes.  The  distal  ridge 
is  usually  longer  than  the  mesial.  The  cervical  border  is  rounded  and 
oval  from  side  to  side. 

The  lingual  face  (J)  is  full  and  rounded,  more  or  less  straight  perpen- 


3G  lli'MAX  OlJOXTOGUAl'UY 

dicularly,  and  rounded  iiit'sio-distally.  It  is  convex  in  both  directions. 
The  lingual  cusp  rises  over  it  full,  hut  is  hhint  and  round;  the  marginal 
ridges  are  rounded,  not  angular,  and  curve  sharply  around  to  meet  the 
mesial  and  distal  marginal  ridges. 

'i'he  mesiid  face  (Fig.  1<S,  (j)  is  wide  and  Hat  transversely,  full  at  the 
morsal  surface  at  the  marginal  ridge,  which  is  prominent,  and  descend- 
ing flat  to  the  cervix,  where  a  depression  (Ji)  occurs  which  extends  well 
up  the  face. 

The  distal  face  is  of  similar  form,  but  is  rather  more  convex  and  the 
portion  at  the  marginal  ridge  more  prominent.  The  depression  from  the 
root  tloes  not  extend  so  far  up  on  the  face. 

The  morsal  surface  shows  an  abrupt  change  from  that  of  the  cuspid 
next  to  it,  as  it  presents  two  distinct  cusps  or  points  instead  of  one.  One 
cusp  is  on  the  buccal  margin  (y)  of  the  crown,  and  one  on  the  lingual  {k), 
and  they  are  named  the  buccal  and  lingual  cusps.  The  buccal  cusp  is 
sharp  and  prominent,  and  is  not  unlike  the  single  canine  cusp.  The 
lingual  cusp  is  broader  and  more  rounded — indeed,  it  is  preferable  to 
term  it  a  tubercle. 

The  outline  of  the  morsal  surface  is  imperfectly  c|ua(lrate  and  is 
bordered  by  well-marked  marginal  ridges,  named  as  follows: 

The  inesial  marginal  ridge  (/),  bordering  the  mesial  face  of  the  crown; 
the  distal  marginal  ridge  on  the  distal  side  (in),  the  buccal  marginal 
ridges  (n)  descending  from  the  point  of  the  Ijuccal  cusp  to  meet  the  buc- 
cal terminations  of  the  distal  and  mesial  marginal  ridges  at  the  angle 
formed  by  the  junction  with  the  buccal  lateral  lobes  (o),  and  the  lingual 
marginal  ridges  (p),  descending  from  the  lingual  tubercle  to  meet  the 
lingual  termination  of  the  mesial  and  distal  marginal  ridges. 

The  triangular  ridges  descend  from  the  cusps  toward  the  centre  of 
the  tooth  and  unite  at  the  central  groove  In  defective  teeth  they  do 
not  fuse,  leaving  a  fault  or  fissure  which  usually  becomes  the  seat  of  caries. 
This  groove  or  sulcus  extends  from  one  lateral  marginal  ridge  to  the 
other  mesio-distally  (r),  and  widens  into  the  mesial  and  distal  sulci  at 
each  end.  The  triangular  grooves  (s)  run  from  the  mesial  and  distal 
sulci  toward  the  mesial  and  distal  angles,  dividing  the  marginal  ridges 
from  the  trianijular.  They  also  frequently  i)ecome  the  seat  of  caries  in 
imperfectly  formed  teeth. 

The  neck  of  the  nrst  bicuspid  is  compressed  or  spindle-shaped  (/), 
the  enamel  line  rising  on  the  buccal  and  lingual  sides  and  dij)ping  down 
on  the  mesial  and  distal.  The  enamel  margin  tapers  off  gradually  on 
to  the  root.  A  wide,  deep  depression  usually  occurs  (?/)  on  the  mesial 
side  of  the  neck,  leading  to  the  groove  on  the  root.  On  the  distal  face 
this  is  not  so  well  marked. 

The  root  is  much  flattened  mesio-distally,  with  a  decided  groove  ex- 
tending up  l)oth  sides.  This  grooving  tends  to  cause  bifurcation  of  the 
root,  which  actually  occurs  in  one-third  of  the  cases,  especially  in  persons 


77/A'  TUIiERCULATh:  Th:ETn 


37 


of  strong  build.  This  bit'iircalioii  is  a  prrsistciit  relic  ot"  lower  forms 
of  the  j)reni()lars,  as  in  the  a{)es. 

The  root  canal  is  Hat  at  the  neek,  and  nearly  always  hifui'eated,  even 
when  the  root  is  not  separated.  This  is  readily  seen  by  holding  a  bicus- 
pid having  one  root,  up  to  the  light,  when  the  central  portion  will  be 
observed  to  be  translucent.  The  usual  bifurcation  necessitates  the  search 
for  both  canals  in  e\ery  case  in  treating  this  tooth. 

The  upper  second  bicuspid  (w)  approximates  the  first  on  the  distal 
side,  and  is  similar  to  it  in  every  way,  except  that  it  is  usually  smaller  and 
more  rounded  in  all  directions.  The  sharp  features,  conspicuous  ridges, 
etc.,  are  not  so  strongly  marked.  The  cusps  are  reduced,  the  ridges  more 
rounded,  and  the  morsal  face  more  flattened,  and  it  is  often  wrinkled. 
The  triangular  ridges  are  more  likely  to  be  united,  thus  making  the 
crown  stronoer.  The  crown  is  thinner  mesio-distallv.  The  neck  is 
more  rounded  or  oval. 

A  most  conspicuous  difference  is  in  the  root,  which  is  narrow^er  labio- 
lingually,  is  more  rounded,  and  is  rarely  bifurcated.  It  is  sometimes 
cylindrical  or  cubical  in  form.  It  is  disposed  to  be  turned,  and  is  often 
crooked.    The  'pulp  canal  is  single  and  readily  entered. 


The  lower  first  bicuspid. 


The  Lower  Bicuspids. — These  are  placed  next  after  the  lower  canines 
on  the  distal  side.  In  form  they  are  not  truly  bicuspid,  for  the  first  is 
unicuspid  and  the  second  is  tricuspid  in  the  pure  typal  forms;  but  they 
are  arbitrarily  termed  bicuspids  on  account  of  their  position  as  com- 
pared wdth  the  upper  bicuspids,  which  are  typically  bicuspid. 

The  architectural  form  of  these  teeth  is  that  of  the  single  cone,  the 
crown  being  augmented  In  various  directions  by  the  addition  of  cin- 
gules  to  the  primitive  cusp. 

The  lower  first  bicuspid  is  a  well-formed  transitional  tooth,  for  it 
grades  from  canine  to  bicuspid  and  is  typically  composite.  It  more 
closely  resembles  a  canine  than  a  bicuspid  in  its  usual  form,  because 
the  inner  cusp  is  almost  suppressed  and  is  rarely  as  large  as  the  outer 
one  (Fig.  19,  a).  In  fact,  it  looks  like  a  canine  w^ith  a  cingule  raised 
upon  its  inner  face.  This  cusp  is  really  a  cingule,  for  it  is  rarely  raised 
to  the  full  height  of  a  cusp. 


38  HUMAN  ODONTOCRAPIIY 

It  varies  imicli  in  size  from  a  mere  point  on  tlie  basal  ridf^e  (/>)  on 
tliroiioh  varions  degrees  of  development,  nj)  to  a  full  ensp  as  large  as 
the  huecal  eusp,  when  the  tooth  becomes  a  Jiiie  bicuspid.  The  tooth  is 
therefore  essentially  a  ])rimitive  nnieuspid  premolar,  (jf  tiie  form  of  this 
tooth  in  some  of  the  lower  primates. 

The  buccal  face  (c)  is  caniniform,  or  a  long  oval  in  outline,  with 
the  cusp  rising  as  an  abrupt  point  above  it.  The  angle  of  the  Junetion 
of  the  marginal  ridges  may  stand  out  prominently.  The  face  curves 
markedly  toward  the  lingual  side,  so  that  the  buccal  cusp  becomes 
central  to  the  long  axis  of  the  tooth  (a).  The  cervical  border  is  rounded 
at  its  margin  and  convex  from  side  to  side.    The  lol)es  are  not  marked. 

The  lingual  face  (d)  is  convex  from  side  to  side  and  straight  vertically, 
but  is  not  perpendicular,  as  it  is  directed  toward  the  lingual  side.  Its 
height  depends  upon  the  height  of  the  lingual  cingule,  which  varies  from 
a  mere  buccal  ridge  through  various  degrees  up  to  the  full-sized  cusp. 

The  mesial  and  distal  surfaces  are  of  similar  form,  convex  from  side 
to  side  (a,  h),  slightly  Hattened  at  the  cervical  border  and  flaring  out  to 
meet  the  full  marginal  ridges,  which  are  round  and  prominent.  The 
prominence  of  these  ridges  and  the  inward  inclination  of  the  lingual 
face  gives  the  crown  a  decided  bell  shape,  tapering  to  the  neck  (c/). 

The  morsal  surface  (e)  is  peculiar  and  differs  from  every  other  tooth 
in  its  great  variability  and  the  extremes  which  it  may  present,  from 
being  that  of  a  full  bicuspid  to  a  mere  canine.  This  face  is  nearly  circular 
in  outline,  the  widening  of  the  lateral  surfaces  by  the  spreading  of  the 
marginal  ridges  (/,  /)  adding  to  the  width.  The  buccal  cusp  (g)  is  large 
and  prominent,  and  is  also  drawn  toward  the  centre  of  the  tooth  to 
accommodate  the  occlusion.  Sometimes  it  is  high  and  sharp  when  the 
lingual  cusp  is  reduced,  and  is  low  and  blunt  when  the  latter  is  en- 
larged— appearing  to  have  an  inverse  ratio  in  size  to  the  inner  cusp. 
The  lingual  tubercle  or  cingule  varies  much  in  size,  from  a  mere  point 
on  the  basal  ridge,  above  the  cervical  border,  to  a  pronounced  cingule, 
a  larger  cingule,  a  small  cusp,  then  a  fidl  cusp,  the  basal  ridge  (h)  being 
raised  with  it.  The  ridges  are  the  mesial  and  distal  marginal  ridges 
(i.  i),  which  are  bowed  out  round  and  full  and  are  always  pronounced; 
the  buccal  marginal  ridges  (/,  /),  leading  down  from  the  buccal  cusp  to 
form  an  angle  with  the  mesial  and  distal  marginal  ridges;  the  basal 
ridge,  when  the  lingual  cingule  is  lowered  (h);  and  the  triangular  ridge 
of  the  buccal  cusp,  which  is  always  large,  and  when  the  inner  tubercle  is 
reduced  leads  down  as  a  high  central  eminence.  The  lingual  cingule, 
as  a  rule,  possesses  no  triangular  ridge. 

The  central  groove  usually  crosses  the  central  ridge  (k),  but  not 
always,  being  often  bowed  around  its  lower  termination.  Sometimes  the 
ridge  is  crossed  by  a  sulcus.  The  groove  terminates  in  a  sulcus  at  each 
end,  with  slight  triangidar  grooves  branching  up  on  the  buccal  cusp. 

The  neck  is  usuallv  oval  on  section,  being  much  constricted,  the  crown 


77/ A'   TUBERCULATK  TEETH  39 

Hiiring  upward  from  the  corviciil  portion,  i;ivint>'  the  crown  the  well- 
known  bell  sha})e.  'I'he  enamel  line  dips  but  slightly,  being  usually 
level  on  all  foiu'  sides.  The  buccal  border  sometimes  presents  a  promi- 
nent ridge. 

The  root  is  single,  long,  tapering,  and  may  ])e  nearly  round,  but  is 
usually  flattened  mesio-distally.  It  is  sometimes  thick  the  greater  part 
of  its  length,  and  terminates  in  an  abrupt,  round,  blunt  apex  (c,  d).  It 
is  very  liable  to  be  crooked.  It  is  rarely  bifurcated  and  does  not  pre- 
sent grooves  on  its  lateral  faces. 

The  pulp  canal  is  constricted  and  flattened  at  the  neck,  and  the  back- 
ward inclination  of  the  teeth  makes  it  difficult  to  enter.  The  possibility 
of  the  root  being  crooked  and  the  peculiarity  of  its  anatomical  relation- 
ships^ also  increase  the  uncertainty  of  treatment,  which  makes  the 
pulp  canals  of  the  lower  bicuspids  difficult  to  deal  with. 

The  lower  second  bicuspid  approximates  the  first  on  its  distal  side. 
It  resembles  the  first  as  regards  the  general  form  of  the  crown,  its  taper- 
ing bell  shape,  the  constriction  of  the  neck,  and  the  shape  of  the  root.    In 
all   these  features   there   is  little   difference  be- 
tvv^een  these  teeth,  and  the  description  of  the  first  ^i«-  20 

will  apply  also  to  the  second  bicuspid. 

The  morsal  surface  (Fig.  20),  however,  differs 
very  materially  from  that  of  the  first.  This  is 
circular  in  outline  like  the  first,  and  the  buccal 
cusp  is  full  and  rounded  (a),  but  the  inner  cusp 
is  divided  by  a  groove  (b)  running  over  it,  into 
two  parts,  so  that  it   is  really  divided  into  two 

,      '■  ,  ,_-,  .  Ill  1   1  •  The   morsal   surface    of   the 

tubercles.     1  his  makes  the  lower  second  bicus-        lower  second  bicuspid. 
pid  in  its  typal  form  a  tricuspid  tooth,  so  that 

it  differs  from  the  lower  first,  which  has  but  one  cusp,  and  from  the 
others,  which  have  but  two  cusps.  The  lingual  tubercles  vary  much  in 
size,  so  that  one  may  be  suppressed  and  the  tooth  seem  a  bicuspid. 
The  mesial  lingual  tubercle  (c)  may  be  of  large  size  and  be  devel- 
oped at  the  expense  of  the  distal  ((I);  this  may  be  a  mere  cingule  on 
the  distal  marginal  ridge  and  appear  on  the  distal  side,  but  it  is  always 
present. 

The  morsal  groove  is  (e)  triangular  in  design,  passing  between  each 
of  the  three  tubercles.  A  well-marked  triangular  ridge  descends  from 
each  of  the  cusps. 

The  tricuspid  form  of  the  morsal  surface  of  this  tooth  is,  of  course, 
a  reproduction  of  the  trituberculate  premolars  of  the  lower  primates, 
and  of  still  lower  mammals,  although  the  triangular  form  of  the  crown 
is  lost  in  man. 

The  Molars. — The  molars  in  man  are  twelve  in  number,  three  on  each 
side  of  each  jaw,  and  are  placed  at  the  rear  of  the  arch,  opposite  the  strong 

1  See  Chapter  on  Extraction  of  Teeth. 


40 


HUMAN  ODONTOCRA  PlI  ] ' 


tritunifing  musck's,  for  the  j)urj)().s<'  of  criisliiiiu-  nud  iii;i.sticatiii<i;  food. 
They  are  iinportant  factors  in  aliineiilatioii  and  (•oiUril>ute  to  the  func- 
tion of  diij^estion  hy  prepaiin<r  food  for  the  stomach.  'I'heir  los^  impairs 
this  function  seriously  and  leads  to  deranii;enient  of  the  stomach  by  over- 
taxing- it  with  imperfectly  masticated  food  substances.    - 

The  Upper  Molar. — The  typical  upper  molar  is  formed  by  the  fusion 
of  three  cones,  as  is  plainly  observed  in  the  three  roots  and  the  three 
tubercles  (Fig.  21,  A).  Tiie  tricuspid  molar,  therefore,  is  a  primitive 
form,  and  is  rarely  seen  in  man,  the  normal  form  being  (juadrituber- 
culate.  The  fourth  additional  cusp,  the  disto-lingual  (b),  is  merely 
a  supplemental  cusp  added  to  the  crown.  An  upper  molar  is,  therefore, 
composed  of  three  tubercles,  and  a  cingule  which  has  not  yet  developed 


Fig.  21 


Architectural  diagram. 


g       h 


The  upper  mohir. 


a  root  to  support  it.  The  trituberculate  molar  is  the  primitive  form  of 
this  tooth,  the  quadritul)erculate  appearing  later,  and  is  found  in  only 
a  few  living  forms,  as  some  of  the  lemurs  and  the  insectivorous  and 
carnivorous  mammalia.  In  man  there  is  sometimes  a  reversion  of  the 
upper  molar  to  the  trituberculate  form,  which  is  a  marked  degeneracy 
in  the  form  of  this  tooth.  In  an  analysis  of  this  tooth,  therefore,  the 
mesio-buccal  tubercle  (c)  is  the  canine  cusp;  the  mesio-lingual,  the  biscus- 
pid  cusp  (d)\  the  disto-buccal,  the  molar  cusp  (e),  and  the  disto-lingual 
is  but  a  supplemental  cusp — it  is  not  a  true  cusp,  as  it  has  no  root  to 
support  it. 

The  architecture  of  the  upper  molar  presents  some  interesting  features. 
We  observe  that  the  crown  is  in  a  general  way  a  geometrical  form,  a 
cube  (f),  when  perfect  and  symmetrical.    It  is  suggestive  of  symmetry, 


Tlll<:   TUBERCULATJ'J   TKF/ril  41 

but  when  taken  wit!i  the  root  form  is  not  (piite  jx-rfect,  for  it  is  snp- 
ported  on  three  roots  instead  of  fonr  lo  correspond  with  the  fonr  tuber- 
cles at  tlie  four  corners.  So  i(  lacks  (he  "harmony  of  adecjuate  support/' 
which  is  a  cardinal  principle  in  architecture,  ikit  the  crown  separ- 
ately is  a  symmetrical  form,  a  cube,  although  the  angles  are  rounded 
ofi'  and  the  corners  and  points  are  toned  down  and  not  acute.  We  notice 
that  there  are  four  strong  columns,  one  at  each  of  the  four  corners  (g). 
They  are  connected  on  the  four  sides  by  the  marginal  ridges  acting  as 
strong  connecting  arches  {]i).  These  arches  are  related  to  the  columns 
of  the  crown,  and  both  are  impressively  proportioned.  The  cusps  may 
be  likened  to  the  capitals  of  the  columns,  and  the  descending  marginal 
and  triangular  ridges  to  the  cornice,  gathered  together  to  form  the  cap- 
itals. The  triangular  ridges  may  be  considered  girders  (f),  binding 
the  four  together  and  also  bracing  the  square  obliquely.  Or,  the  four 
triangular  ridges  running  to  the  centre  may  be  regarded  as  half-arches 
or  buttresses,  supporting  the  roof  vault, — the  grinding  face.  Other 
elements  could  be  marked  out  in  an  architectural  study  of  the  crown 
of  this  tooth,  showing  its  beautiful  design  and  symmetry. 

The  upper  first  molar  approximates  the  second  bicuspid  on  its  distal 
side.  There  is  a  marked  and  abrupt  change  in  form,  as  the  molar  has 
double  the  number  of  cusps  of  the  bicuspid — being  formed  like  two 
bicuspids  fused  together.  The  four  tubercles  constitute  an  extension  of 
surface  and  a  further  adaptation  to  functional  requirements.  The 
crown  is  large  and  cubical  in  form,  and  more  or  less  rounded. 

The  buccal  face  (K)  is  wide  and  rounded.  It  is  twice  the  width  of 
the  bicuspids.  It  is  broadest  at  the  morsal  margin,  narrowing  upward 
to  the  cervix,  where  it  is  widely  rounded  or  arched.  A  vertical  depression, 
the  buccal  groove  (/),  extends  from  the  cervical  border  to  the  morsal 
margin,  dividing  the  face  into  two  oblong  rounded  eminences,  the  mesial 
and  distal  buccal  lobes  (m  m). 

The  Ungual  face  (N)  is  more  rounded  than  the  buccal,  the  cervical 
portion  being  the  most  convex  (a),  the  mesial  and  distal  sides  being 
depressed  toward  the  single  lingual  root.  The  morsal  half  is  divided  by 
the  lingual  groove  (q),  which  descends  over  the  lingual  marginal  ridge 
between  two  lobes,  the  mesial  (r)  and  distal  (p),  wdiich  are  usually  much 
rounded.  The  morsal  half  of  the  face  curves  toward  the  grinding  sur- 
face. The  mesial  lobe  sometimes  presents  the  lingual  cingule  (s),  a 
sort  of  fifth  tubercle  of  greater  or  less  size.  A  groove  branches  from 
the  lingual  groove  and  extends  over,  between  the  cingule  and  crown. 

The  mesial  face  (T)  is  flat  longitudinally,  descending  from  the  niar- 
ginal  ridge  to  the  cervix  in  a  nearly  straight  line.  Bucco-lingually  it  is 
convex,  nearly  flat  at  the  marginal  ridge,  and  rounded  at  the  cervix, 
being  depressed  toward  the  lingual  root.  Sometimes  a  depression  from 
the  bifurcation  of  the  mesio-buccal  and  lingual  roots  extends  part  way 
up  on  the  face  (u). 


42 


IIVMA N  ODONTOGRAPHY 


The  (l/.sfdl  fdcc  is  .similar  to  the  mesial  except  that  it  dips  more  toward 
tlie  cervix,  and  is,  j^crhaps,  more  rounded  toward  tlie  hn(!;iial  root. 

The  morsal  surface  (Fig.  22)  is  tlie  most  important  part  of  this  tooth, 
and  shows  features  that  make  it  interesting  and  unique.  The  abrupt 
change  from  the  bicuspid  form  is  notai)le,  for  there  are  presented  four 
cusps,  a  doubling  of  the  lunuber;  the  outline  oi  this  face  presents  a 
square  form  with  tubercles  at  each  corner,  the  mesio-buccal  (a),  the 
disto-buccal  (J)),  the  mesio-lingual  (c),  and  the  disto-lingual  (d);  the 
latter  is  erratic  and  may  i)e  either  pronounced  or  (juite  reduced  in  size. 

There  are  four  marginal  ridges:  the  mesial  (e),  buccal  (/),  distal  (7), 
lingual  (h),  the  oblicjue  (/),  and  the  four  triangular  ridges  (y).  The 
oblique  ridge  connects  the  mesio-lingual  with  the  disto-buccal  tubercle 
and  is  really  the  remnant  of  the  marginal  ridge  of  the  tricuspid  molar; 
the  fourth  cusp,  the  disto-lingual,  being  raised  up  on  the  disto-lingual 
side.  The  four  triangular  ridges  descend  from  the  four  tubercles  toward 
the  centre  of  the  tooth,  the  oblique  ridge  being  formed  by  the  fusion  of  the 
triangular  ridges  of  the  mesio-lingual  and  disto-buccal  cusps. 

Fig.  22 


The  morsal  surface  of  the  upper  first  molar. 

There  are  two  fossa^  (k),  one  mesial  and  the  other  distal  to  the  oblique 
ridge.  Sometimes  the  latter  is  cut  by  a  groove  or  sulcus  (I)  which  ex- 
tends from  the  mesial  to  the  distal  fossa.  Sometimes  by  the  reduction 
of  the  disto-lingual  lobe  and  cusp,  the  mesial  fossa  is  extended  and 
becomes  central  to  the  crown.  A  groove  extends  from  the  mesial  fossa 
over  the  buccal  marginal  ridge  (m)  quite  on  to  the  buccal  face,  dividing 
the  mesial  from  the  distal  buccal  lobes.  A  groove  also  extends  over  the 
lingual  marginal  ridge  (n)  down  upon  the  lingual  face,  dividing  the 
lino-ual  lobes.  When  this  groove  becomes  a  fissure  and  caries  ensues 
the  disto-lingual  cingule  readily  breaks  away,  this  cingule  being  a  weak 
feature  in  the  mechanical  design  of  this  tooth;  cutting  the  distal  mar- 
ginal ridge  also  weakens  this  cusp.  The  triangular  grooves  })ranch  from 
the  two  fossie  on  to  the  cusps,  dividing  the  triangular  from  the  marginal 
ridges. 

The  neck  of  this  tooth  is  of  rounded  rhomboid  form  on  section  (o), 
widest  at  the  buccal  side.  The  enamel  is  almost  level  on  all  four  sides, 
dipping  downward  slightly  on  the  mesial  and  distal.  A  depression 
occurs  at  the  bifurcation  of  the  buccal  roots,  and  an  inward  inclination 
on  the  mesial  and  distal  sides. 


THE  TUBERCULATK  TEETH 


43 


Fig.  23 


The  roots  are  three  in  mnnher  (Fi^.  21),  two  on  tlie  buccal  side,  which 
are  small  and  Hat  or  round,  and  one  on  the  linoual  side,  which  is  lart^e 
and  rounded.  The  roots  are  usually  separated,  but  may  be  1'ouikI 
united,  by  a  septum  of  cementum,  in  various  directions.  The  mesio- 
buccal  root  is  the  larger  of  the  two  buccal  roots,  and  forms  a  second 
turning-point  or  spring  of  the  arch.  All  the  roots  are  slightly  bent 
and  may  be  very  crooked. 

The  'pul'p  chamber  branches  into  three  canals,  one  in  each  root.  The 
lingual  canal  is  large  and  open  and  is  readily  entered.  The  canals  of  the 
two  buccal  roots  are  small  and  fine,  and,  with  the  possibility  of  crcxjked- 
ness  in  the  roots,  present  the  most  difficult  problems  as  to  treating  and 
filling  found  in  the  whole  denture. 

The  upper  second  molar  is  similar  to  the  first  in  some  respects,  but 
very  different  in  others.     It  is  rather  smaller,  is  not  usually  full  and 
square,  but  disposed    to   become  rhom- 
boid in  form   (Fig.   23,  a,  h),  by   disto- 
mesial  compression. 

The  buccal  face  is  similar  to  that  of 
the  first  molar,  and  the  same  descrip- 
tion will  apply  to  it.  If  any  difference  is 
found  it  is  that  the  face  is  strongly  com- 
pressed from  front  to  back,  and  the 
disto-lingual  cusp  is  more  reduced  as  a 
constant  feature. 

The  lingual  face  (c)  is  different  from 
that  of  the  first  molar  in  that  by  the 

suppression  of  the  disto-lingual  tubercle  (d)  and  the  distal  lobe  the 
mesio-lingual  lobe  is  enlarged  so  that  it  occupies  the  entire  face,  which  is 
full,  rounded,  and  convex  (e).  It  is  rarely  divided  into  two  lobes,  as  in 
the  first  molar,  owing  to  the  enlargement  of  the  mesial  lobe  and  the  push- 
ing backward  of  the  oblique  ridge,  which  throws  the  lingual  groove  on 
to  the  distal  lingual  angle  (d) ;  or  the  groove  may  be  absent  altogether. 

The  mesial  and  distal  faces  are  similar  in  form  to  those  of  the  first 
molar,  being  perhaps  more  flattened. 

The  morsal  face  is  similar  to  that  of  the  first  molar,  except  that  the 
tubercles  are  less  pronounced  and  the  distal  ones  are  reduced  in  height 
to  accommodate  the  upward  curve  of  the  line  of  occlusion  at  this  point. 
The  disto-lingual  cingule  is  smaller  than  that  upon  the  first  molar,  and 
is  often  barely  marked.  This  throw^s  the  oblique  ridge  more  to  the  distal 
side  and  enlarges  the  mesial  fossa.  The  various  grooves  are  the  same  as 
on  the  first  molar,  except  that  one,  the  lingual,  may  be  lost. 

The  neck  is  less  regular  in  outline  than  that  of  the  first  molar,  as  the 
crown  varies  so  much  in  shape.  It  is  more  flattened  mesio-distally  and 
depressed  toward  the  roots. 

The  roots  are  the  same  in  number  and  general  form  as  in  the  first 


The  upper  second  molar. 


44 


HUMAN  ODONrOdRA  I'l/V 


molar,  hut  spread  less  and  are  more  irregular  in  form.  They  may  eon- 
vert^e  or  he  erooked,  or  may  Ix*  fused  to<i,('dier.  This  makes  the  pulj) 
eanals  more  (Ufiieult  to  treat.  Sometimes  (lie  three  roots  are  eompletely 
fused,  as  in  the  third  molar,  and  the  canals  may  coalesce;  or  the  canals 
of  tlie  two  huceal  roots  may  run  into  one.  Thv  irr(>o;ularity  and  uncer- 
tainty of  the  form  of  the  roots  make  this  tooth  difficult  to  deal  with  in 
treating  its  pulp  canals. 

The  Lower  Molars. — The  lower  first  molar  apj)r<)ximates  the  lower 
second  hicuspid  on  its  distal  side.  It  is  the  first  of  the  true  grinders 
of  the  lower  jaw  and  the  largest  tooth  in  the  dental  series.  Unlike  the 
upper  molars  the  transverse  diameter  is  less  than  tlie  mesio-distal.  The 
greater  width  is  fyund  across  the  hase  of  the  disto-huccal  tuhercle. 
The  crown  is  square  or  trapezoidal  in  form,  depending  on  the  size  of  the 
fifth  tuhercle.  Being  quinquetuherculate,  the  crown  is  l)roadened  hy  the 
multicuspid  grinding  face.  The  l)uccal  face  is  inclined  toward  the  centre 
of  tlie  tooth,  for  its  morsal  half,  to  accommodate  the  occluding  teeth. 


Fig.  24 


Architectural  diagram. 

S  f 


B 

The  lower  first  molar. 


Architecturally,  the  tooth  is  formed  of  four  cones  (Fig.  24,  A),  and 
may  he  roughly  divided  into  four  quarters.  There  are  four  primitive 
cones  with  their  tuhercles  and  one  cingule  in  the  structure. 

The  morsal  surface  (B)  is  trapezoidal  in  outline,  the  buccal  line  heing 
the  longest.  The  huceal  angles  are  acute,  while  the  lingual  are  rounded 
and  ohtuse. 

There  are  five  tuhercles,  two  on  the  lingual  margin  and  three  on  the 
buccal.  They  are  named  the  mesio-huccal  (r),  median  buccal  (c/),  disto- 
huccal  (e),  disto-lingual  (f),  and  mesio-lingual  (</).  These  tuhercles  are 
less  obtuse  and  more  rounded  than  those  of  the  other  grinding  teeth,  the 
mesio-huccal  usually  heing  the  largest;  the  others  are  not  so  prominent, 
rarely  raised  and  sharp. 


Tllh:  TUHKliCULATl<:  TJ'JJ-TU  45 

The  ridges  arc:  the  marginal  ridges — buccal,  distal,  lingual,  and 
mesial — and  the  five  triangular  ridges  descending  from  the  five  tubercles 
toward  the  centre  of  the  tooth. 

The  f/roorcs  and  sulci  u{)on  the  niorsal  surface  are  very  irregular.  A 
dec})  sulcus  traverses  the  face  from  the  mesial  to  the  distal  marginal 
ridge.  A  groove  runs  off  toward  the  lingual  side,  dividing  the  lingual 
cusps  (i),  sometimes  cutting  the  lingual  marginal  ridge,  but  I'arely 
reaching  over  on  the  lingual  face.  A  groove  runs  toward  the  buccal 
side,  dividing  the  mesio-buccal  from  the  median  tubercle  (j),  cutting 
the  marginal  ridge  and  extending  over  quite  on  to  the  buccal  face.  This 
groove  often  becomes  the  seat  of  caries,  owing  to  the  enamel  structure 
lieing  faulty.  Another  groove  extends  toward  the  disto-buccal  angle  (k), 
dividing  the  median  from  the  disto-buccal  tubercle,  and  rarely  extends 
over  on  to  the  buccal  face.  A  groove  may  extend  distally,  cutting  the 
distal  marginal  ridge  (I),  and  one  mesially,  cutting  the  mesial  marginal 
ridge  (7?i),  but  these  are  not  usually  marked.  The  triangular  groove 
running  up  on  each  side  of  the  triangular  ridges  (n)  divides  these  from 
the  marginal  ridges.  Supplemental  grooves  may  divide  the  triangular 
ridges  again.  The  pits  at  either  end  of  the  sulcus  may  become  the  seat 
of  caries  through  faulty  formation. 

The  buccal  face  (C)  is  an  irregular  trapezoid  in  form,  the  morsal  mar- 
gin being  longest;  the  mesial  and  distal  sides  converge  toward  the  cer- 
vical border,  which  is  rounded.  The  morsal  margin  is  broken  by  the 
three  tubercles  rising  upon  it.  The  buccal  face  is  convex  in  all  direc- 
tions, that  from  the  morsal  to  the  cervical  borders  being  the  most  marked, 
owing  to  the  morsal  half  converging  toward  the  centre  of  the  tooth. 
The  buccal  groove  (o)  leading  over  from  the  morsal  face  divides  the 
face  into  two  lobes,  which  are  full  and  rounded.  Sometimes  the  disto- 
buccal  groove  cuts  off  another  lobe,  thus  making  three  lobes  on  the  buccal 
face.  These  grooves  sometimes  lead  to  the  cervical  border,  but  usually 
terminate  in  the  middle  of  the  face  in  a  pit,  which  may  become  the  seat 
of  caries  through  faulty  formation  of  the  enamel. 

The  lingual  face  (D)  is  wide,  rounded,  smooth,  and  convex,  rather 
straight  perpendicularly,  leaning  in  the  lingual  direction.  It  forms  a 
sharp  angle  with  the  morsal  surface,  which  is  surmounted  with  two 
tubercles.  Sometimes,  but  rarely,  the  lingual  groove  passes  over  on  to 
this  face. 

The  mesial  and  distal  faces  (s)  are  wide  and  flattened  transversely, 
but  convex  vertically.  They  are  trapezoidal  in  outline,  the  morsal 
border  being  longer.  The  cervical  border  is  more  convex,  and  dips 
toward  the  neck  of  the  tooth. 

The  neck  (t)  is  very  regular  in  outline  and  contour.  It  is  approxi- 
mately square  with  all  four  sides  depressed  in  the  centres.  The  mesial 
and  distal  are  depressed  at  the  origins  of  the  grooves  leading  down 
upon  the  roots;  the  lingual  and  buccal  are  depressed  at  the  bifurcation 


46  HUMAN  O  DO  X  TOG  RAP  II Y 

of  the  roots,  the  (le])ressi()n,  wliich  is  wide  and  deep,  exteiidiiifij  uj)  on 
to  the  neek,  especially  u})()ii  the  hiiccul  side.  Tlie  enamel  line  is  (juite 
irrej^ular,  dipping  down  on  the  lingual  and  hueeal,  and  leading  well 
up  on  tlie  mesial  and  distal  sides. 

The  roots  are  two  in  number,  placed  with  their  longer  diameter  trans- 
versely to  the  jaw.  They  are  wide  bucco-lingually,  and  flat  and  narrow 
disto-mesially,  being  situated  distjdly  and  mesially  to  the  crown.  The 
j)osterior  is  formed  of  the  two  {posterior  cones,  and  the  anterior  of  the 
two  anterior  cones  (.1).  This  is  plainly  shown  in  the  formation  of  the 
roots,  which  are  grooved  both  distally  and  mesially,  and  in  the  tendency 
to  bifurcation,  which  sometimes  actually  occurs.  They  divide  close  to 
the  crown,  so  that  the  grooves  of  bifurcation  extend  well  up  on  the  neck. 
The  distal  root  is  thicker  and  more  rounded  than  the  mesial,  the  latter 
being  more  flattened,  with  the  grooves  deeper,  and  it  is  more  often 
bifurcated.     Both  are  deflected  from  the  median  line. 

The  pulp  canal  is  shaped  like  the  roots,  with  two  main  branches. 
The  distal  branch  is  the  larger,  being  round  and  open,  as  the  root  is  more 
rounded.    The  mesial  branch  is  flat  and  spindle-shaped,  being  difficult 

to  enter,  and  usually  having 

F^°-  25  two  sub-branches,   follow- 

■^  '■'  ing  the  buccal  and  lingual 

divisions      of      the      root. 

These    sub-branches     are 

small    and    hair-like    and 

troublesome  to  enter. 

^^      ^^  ^jpr  The  lower  second  molar 

The  lower  second  molar.  (Fig-  25)  differs  from  the 

first  in  many  respects.  It 
is  of  the  same  general  form,  l)ut  is  more  quadrangular,  as  it  has  but 
four  tubercles.  It  is  more  rounded  and  symmetrical  than  the  first,  the 
four  cones  and  four  primitive  tubercles  being  well  marked.  The  ab- 
sence of  the  fifth  tul)ercle  leads  to  most  of  the  difi'erences  between  the 
second  and  the  first  molar. 

The  morsal  face  (c)  has  })ut  four  tubercles,  one  at  each  corner  of  the 
face,  ditt'ering  from  that  of  the  first  molar,  which  has  five.  The  fifth 
tubercle  rarely  appears  in  the  higher  races  of  mankind,  but  is  some- 
times found  in  the  low  savage  races,  and  occurs  regularly  in  the  apes. 
It  is  not  uncommon  in  the  negro,  but  is  absent,  as  a  rule,  in  the  European 
races.  The  tubercles  are  symmetrical,  rounded  and  obtuse,  the  lingual 
being,  however,  sharper  than  the  buccal. 

The  sulci  describe  a  cruciform  sha})e,  separating  the  four  tubercles 
symmetrically  from  each  other.  The  buccal  groove  sometimes  continues 
on  to  the  buccal  face,  rarely  to  the  lingual.  The  triangular  grooves 
run  up  on  the  morsal  triangular  ridges.  The  marginal  ridges  are  well 
marked,  the  mesial  and  distal  being  often  divided  by  grooves.     The 


THE  TUBEliCULATE  TEETH  47 

triaiiuular  ridges  arc  usually  well  marked,  leading  to  the  centre  of  the 
tooth.     They  are  full  and  strong. 

The  buccal  face  (d)  is  convex  and  of  more  regular  form  than  that 
of  the  first  molar.  It  is  divided  into  lobes  (e,  e)  by  the  buccal  groove 
(d),  which  is  rarely  deep.  A  pit  is  often  found  in  the  centre  of  the  face, 
which  may  become  the  seat  of  caries.  The  face  is  curved  toward  the 
centre  of  the  tooth,  as  in  the  first  molar. 

The  luigual  face  is  similar  to  that  of  the  first  molar,  })ut  may  l)e  more 
roinuled  toward  the  morsal  border.  It  is  symmetrically  convex  in  both 
directions. 

The  mesial  and  distal  faces  [f)  are  similar  to  those  of  the  first  molar, 
except  that,  the  crown  being  smaller,  they  may  be  more  perpendicular, 
but  are  well  rounded. 

The  neck  (g)  is  more  regularly  formed  than  that  of  the  first  molar, 
the  margin  of  the  enamel  line  being  quite  as  irregular.  It  may  be  more 
constricted. 

The  roots  (h,  h)  are  similar  to  those  of  the  first  molar,  but  are  more 
rounded  in  shape,  are  usually  crooked,  and  on  that  account  difficult  to 
treat. 

The  pidp  cancds  are  similar  to  those  of  the  first  molar,  but  the  tend- 
ency to  crookedness  renders  treatment  cjuite  difficult.  The  direction 
of  irregularity  of  form  is  so  uncertain  that  no  rule  can  be  applied  to  it. 

The  Third  Molars. — The  upper  and  lower  third  molars  can  best  be 
described  together,  on  account  of  their  similar  eccentricities.  They 
are  very  irregular  as  to  the  time  and  to  the  frequency  of  their  appearance 
in  civilized  man.  About  one-half  of  the  individuals  of  European  races 
erupt  them  at  the  normal  period,  i.  e.,  seventeen  to  twenty-one  years  of 
age.  In  one-fourth  they  erupt  at  irregular  intervals  to  the  thirtieth 
year,  and  in  the  remainder  they  may  appear  later,  or  the  first,  second, 
third,  or  all  of  them,  may  be  absent  altogether.  In  one  series  of  forty 
adult  skulls  observed,  twelve  had  one  or  more  absent.  The  absence  and 
other  erratic  peculiarities  of  these  teeth  sometimes  seem  to  be  hereditary, 
and  can  be  traced  in  families  through  several  generations. 

The  tooth  is  often  reduced  in  size  and  may  be  a  mere  peg  (Fig.  26,  a). 
It  is  of  very  irregular  form  in  civilized  races,  but  is  as  large  and  as  well 
formed  as  the  other  molars  in  most  races  low  in  the  ethnological  scale. 
The  contraction  of  the  jaws  through  disuse  has  much  to  do  with  the  mal- 
development  of  this  tooth,  and  it  is  often  so  cramped  for  room  as  to  pro- 
duce distressing  irritation  which  necessitates  its  removal.  Impaction 
and  malposition  of  the  third  molars  render  them  difficult  of  extraction 
and  are  the  fruitful  source  of  many  serious  lesions.  (See  the  chapter  on 
Extraction  of  Teeth.) 

The  upper  third  molar  is  more  or  less  similar  to  the  other  upper  molars 
when  perfect  and  well  developed,  but  it  is  very  erratic  as  to  form  and 
structure. 


48 


HUMAN  ODOXTOaRA I'lIY 


'Vh'xs  tooth,  when  well  formed,  is  of  trituherculuto  form  (6),  the  disto- 
liii^iijil  ciiigule  being  suppressed.  This  cingule  diminishes  gradually 
from  the  first  molar,  in  which  it  is  well  formed,  to  the  second,  where 
it  is  reduced,  then  to  the  third,  where  it  is  almost  or  entirely  absent. 
The  oblique  ridge  becomes  the  posterior  marginal  ridge  (c).  as  in 
the  typical  trituberculate  molar.  The  three  tubercles  are  reduced  and 
rounded.  The  sulci  usually  degenerate  into  fissures,  as  the  formation 
of  this  tooth  is  notoriously  faulty.  The  enlarged  mesial  fissures  thus 
become  the  seat  of  extensive  caries. 

The  huccdl  face  resembles  that  of  tlic  first  and  second  molars,  but  is 
more  rounded. 

The  limjudl  face  (fl)  is  full  and  rounded,  with  but  a  single  lobe,  cnving 
to  the  rcfluction  or  absence  of  the  disto-lingual  tubercle. 

The  mesial  face  (e)  is  similar  to  that  of  the  second  molar,  l)ut  reduced, 
and  the  distal  face  is  round  and  short,  as  wo  tooth  succeeds  it  in  the  rear. 

The  neck  is  constricted  and  tapers  toward  the  conate  roots.  It  is  of 
a  rather  rounded  triangular  shape. 


The  upper  third  molar 


The  lower  third  molar. 


The  three  roots  (jf  the  upper  molars  are,  in  the  third,  usually  more 
blunt,  conate,  short  in  form,  and  may  curve  backward.  In  lower  races 
and  sometimes  in  individuals  having  strong  osseous  organizations,  the 
typical  three  molar  roots  are  found.  vSometimes  there  are  multiple 
roots,  which  are  likely  to  be  curved  in  various  directions,  and  may  have 
decided  hooks. 

In  the  large  conate  root  the  fidp  canals  usually  coalesce,  but  in  cases 
in  which  the  root  is  divided  there  will  also  be  division  of  the  jjulp  chamber. 

The  lower  third  molar  is  similar  to  the  other  lower  molars  in  general 
form  (Fig.  27,  a),  but  is  probably  not  so  erratic  and  not  subject  to  such 
extreme  variations.  The  crown  is  quadrangular  in  section,  the  angles 
rounded. 

On  the  morsal  face  (h)  there  are  four  principal  tubercles,  as  in  the 
second  molar,  but  this  may  be  supplemented  .by  the  extension  of  the 
disto-marginal  ridge  into  a  cingule  or  heel  (r).  This  heel  is  rather 
erratic;  it  may  be  large  or  small,  thus  modifying  the  size  of  the  morsal 
surface.  Sometimes  the  face  is  wrinkled  and,  like  this  tooth  in  the 
orang-outang,  the  sulci  exhibit  the  cruciform  shape  similar  to  that  of  the 


Tin-:  TUBEliCULATE  TEETH 


49 


.second  molar.  'V\\v  many  trroovt's  leading'  away  from  (he  main  siilcu.s 
may  l)o  imperfect  and  become  the  seat  of  caries.  Tlie  buccal  "groove 
riiimiiio-  from  tlie  morsal  on  to  the  hiiccai  face  (a)  is  very  subject  to  imper- 
fection. 

The  four  Idfcntl  faces  are  simihir  to  tiiose  of  the  second  molar,  except 
that  tlie  distal  is  more  convex  and  full,  and  often  very  prominent  if  the 
Hfth  cin<;ule  is  well  developed. 

The  neck  is  of  similar  shape  to  that  of  the  second  molar. 

The  roofs  are  sinn'lar  to  those  of  the  other  lower  molars,  l)ut  (generally 
smaller  as  compared  with  the  crown  [d).  They  are  usually  divided  like 
the  others,  but  the  two  may  be  fused  together,  or  be  closely  opposed. 
In  either  case  they  are  usually  projected  distally  more  or  le.ss,  leading 
backward  into  and  under  the  ramus,  thereby  rendering  extraction  of 
this  tooth  difficult  and  dangerous,  especially  where  the  maxilla  is  of 
dense  structure  or  where  there  is  impaction.  The  roots  are  usually 
more  rounded,  especially  the  distal  one,  than  those  of  the  other  molars. 

The  pulp  canals  are  generally  divided,  whether  the  root  is  or  not. 
As  the  roots  are  usually  crooked,  the  difficulty  of  entering  them  is  in- 
creased as  the  canals  follow  the  form  of  the  roots. 


Fig.  28 


The  fourth  molar. 


Fourth  molars  sometimes  appear  as  supernumerary  teeth,  and  are 
either  fused  to  the  upper  third  molar  in  a  variety  of  uncouth  forms 
(Fig.  28,  a)  or  erupt  separately  as  mere  peg-shaped  teeth  between  the 
buccal  faces  of  the  second  and  third  molars  {h)  or  at  the  distal  aspect 
of  the  'atter  tooth.  The  fourth  molar  rarely  appears  as  a  full  molar, 
except  in  some  of  the  large-toothed  races,  as  negroes,  Australians,  etc., 
and  then  usually  in  the  lower  jaw.  Among  the  negroes  in  Africa  the 
fourth  molar  is  sometimes  found  in  full  form  as  a  typical  molar. 

The  tuberculate  teeth,  the  bicuspids  and  molars,  present  many  points 
of  mechanical  structure,  with  reference  to  operations  upon  them,  that 
are  of  interest  and  importance.  Beginning  with  the  upper  bicuspid,  we 
find  that  being  composed  of  two  cones  cemented  together  longitudinally, 
it  is  essentially  a  weak  tooth.  Tlie  triangular  ridges  being  imper- 
fectly fused  at  the  transverse  sulcus  (indeed,  this  point  is  often  the  seat 
of  a  congenital  fissure),  the  cusps  are  unsupported.  The  main 
dependence  of  the  two  cones  for  union  and  binding  together  is  the  power 
4 


50 


HUMAN  ODONTOaiL  1  I'll  1 ' 


Fig.  29 


of  the  marfjjinal  ridf^es,  and  when  tliese  are  destroyed  the  crown  readily 
spHts,  the  buccal  or  lingual  cusp  l)reakin<(  away  with  the  wedi^iiit;-  and 
force  of  mastication.  When  from  extensive  caries  the  aj^proximal 
faces  are  destroyed  and  an  elaborate  comj)ound  filling  is  necessary,  the 
lingual  cusp,  the  one  that  most  frecjuently  splits  oil",  should  be  reduced 
by  grinding,  so  as  to  lessen  the  danger  from  wedging  food.  While  pres- 
sure fillings  are,  of  course,  dangerous,  there  is  also  danger  from  inlays 
by  reason  of  the  too  extensive  cutting  out  of  the  sulcus  and  conse(|uent 
weakening  of  the  cusps.  There  should  be  as  little  transverse  cutting  as 
possible  in  order  to  guard  this  weak  point  in  these  teeth. 

In  the  lower  bicuspids  the  same  conditions  do  not  obtain,  as  their 
architecture  and  mechanical  structure  are  entirely  diii'erent.  In  the 
lower  first  bicuspid  the  transverse  ridge  is  strong  and  well  fused,  so  that 
the  splitting  off  of  either  cusp  is  very  rare.  The  second  bicuspid  is  also 
of  stronger  mechanical  structure.    The  weak  point  in  both  these  teeth 

is  the  marginal  ridge,  whicli,  by  reason 
of  the  bell-shaped,  tapering  crown  is  not 
well  supported,  and  if  undermined,  readily 
chips  off.  Therefore,  approximal  fillings 
on  these  teeth  should  l>e  well  anchored 
on  the  morsal  surface  and  undercuts 
avoided.  Attention  must  also  be  given  to 
the  lingual  occlusion  of  these  teeth, 
which  increases  the  stress  upon  all 
operations  upon  them. 

The  upper  molars  are  of  beautiful  and 
wonderful  architecture,  as  before  de- 
scribed, and  present  an  interesting  study. 
The  greatest  point  of  weakness  in  these 
teeth  is  the  disto-lingual  cusp,  the  hypo- 
cone,  which  often  breaks  away  when  undermined  by  distal  caries,  as  the 
fusion  with  the  oblicjue  ridge  and  the  protocone  is  weak.  This  should  l)e 
obviated,  after  filling,  by  grinding  down  the  point  of  the  cusp.  It  is  danger- 
ous to  cut  the  oblicjue  ridge,  for  when  the  marginal  ridges  are  destroyed 
it  becomes  the  main  binding  girder  of  the  crown.  When  this  is  under- 
mined by  caries  the  crown  becomes  so  weakened  that  it  readily  splits. 
The  introduction  of  the  inlay,  however,  has  greatly  lessened  the  mechan- 
ical dangers  of  operating  uj)on  these  teeth  that  cannot  be  avoided  with 
the  pressure  fillings.  Mesial  inlays  should,  of  course,  be  carried  into  the 
mesial  sulcus  and  the  buccal  border  preserved  as  much  as  possible 
for  the  esthetic  effect.  Indeed,  extensive  caries  on  this  tooth  can 
be  better  treated  with  the  inlay  than  with  the  shell  crown,  and  the 
natural  crown  be  better  preserved. 

The  lower  molar  is  different  from  the  upper  in  its  mechanical  design, 
and  the  lingual  occlusion  presents  different  problems.    In  the  evolution 


•**- 


Negro  top  jaw  with  fourth  molar. 


THE  TUBEUCULATE  TEETH  51 

of  its  crown  it  will  he  remembered  that  the  protoconid  shifts  to  the 
buccal  side  and  becomes  the  mesio-biiccal  cusp.  The  triangle  of  the 
lower  molar  is  just  the  opposite,  therefore,  of  the  upper  and  carries  two 
cusps,  the  two  mesial,  the  third  having  been  lost  in  the  process  of  evo- 
lution. The  talonid,  therefore,  supports  three  cusps,  the  two  distal 
buccal  and  the  disto-lingual,  which  are,  therefore,  weaker  than  those  of 
the  trigonid.  Hence  we  have  more  breakdowns  of  the  distal  half  of  the 
lower  molars  than  of  the  mesial.  This  must  be  considered  in  operating 
on  this  tooth,  not  making  deep  undercuts  to  weaken  the  cones,  but 
depending  upon  occlusal  retention.  The  cutting  of  the  transverse  ridges 
does  not  weaken  the  crown  except  when  the  cones  are  separated  too 
deeply,  which  results  in  the  splitting  off  of  the  lingual  half  of  the  crown, 
which  is  not  uncommon.  So  the  grinding  of  the  lingual  cusps  must  again 
be  resorted  to  to  prevent  the  danger  of  the  wedging  of  food.  The  crown 
of  the  lower  molar  is  essentially  weak  and  the  conservation  of  its  weakest 
points,  the  junction  of  the  cones,  must  be  considered  at  all  times.  A 
knowledge  of  this  weakness  is  obtained  by  a  study  of  the  evolution  of 
the  crowns  of  the  molars. 

The  mechanical  resistance  of  the  molars,  as  well  as  their  effective- 
ness in  the  mastication  of  food,  depends  much  upon  the  accuracy  of 
their  occlusion.  It  is  needless  to  say  that  this  very  rarely  obtains  in 
ordinary  dentures.  Malposition,  extractions,  abrasion,  dental  mutila- 
tions, imperfect  and  indolent  use  in  the  performance  of  the  function  of 
mastication,  all  contribute  to  the  malocclusion  of  the  molars  which  is  so 
prevalent.  Imperfect  occlusion  is  productive  of  abnormal  stress  upon 
various  parts  of  the  crown  and  its  consequent  frequent  breaking  down 
along  the  lines  of  the  junction  of  the  cones.  It  follows,  of  course,  that 
the  proper  procedure  is  to  restore  the  normal  occlusion  as  completely 
as  possible  by  artificial  means. 

The  Deciduous  Teeth. — The  deciduous  teeth  are  those  wdiich  appear 
in  infancy  and  serve  the  purpose  of  dental  organs  during  the  first  years 
of  the  development  of  the  individual,  until  the  jaws  and  their  environ- 
ment are  ready  for  the  larger,  permanent  teeth  to  come  into  place. 
They  bear  a  direct  relationship  to  the  conditions  of  the  digestive  appar- 
atus and  the  food  required  at  that  early  stage.  The  food  of  infancy  being 
simple  and  requiring  little  mastication,  the  deciduous  set  are  small  and 
insufficient  for  the  reduction  of  more  resisting  substances.  As  these 
foods  come  to  form  part  of  the  dietary,  the  larger  teeth  of  the  permanent 
set  appear  and  perform  the  duties  of  higher  functional  activity. 

The  crowns  of  the  deciduous  teeth  resemble,  in  a  general  way,  those 
of  the  permanent  teeth  which  succeed  them,  except  the  deciduous  molars 
(Fig.  30,  a,  d),  which  are  very  different  from  the  bicuspids  of  the  per- 
manent set  which  displace  them. 

The  incisors  of  both  jaws  precede  the  analogous  teeth  of  the  same 
series  of  the  permanent  set.    They  are  similar  in  form,  but  reduced  ib), 


52  Hi' MAX  ODUXTOGRM'ffV 

and  <1()  not  have  tlic  main  ftaturt's  so  cliaracteristically  marked.  Tliey 
art"  infantik'  in  form  and  function.  The  nnAs  of  these  teeth  are  resorbed 
at  from  the  fifth  to  the  ninth  year,  when  the  permanent  incisors  come 
into  pkice,  l)eiriiniin<;  witli  tlie  k)wer  centrals. 

Tlie  cuspids  {<■)  of  l)oth  jaws  are  still  more  reduced  from  the  strong, 
full  form  of  their  j)ermanent  successors,  and  are  hut  little  more  .spe- 
cialized than  the  incisors.  They  are  of  the  same  general  form  as  the 
permanent  cus]:)ids,  hut  much  less  developed. 

But  in  the  deciduous  molars  are  found  some  important  features  which 
mark  distinctive  differences.  They  are  of  true  molar  form  as  com- 
parefl  with  the  permanent  molars,  hut  they  occu])y  the  place  of  the 
bicuspids.  Tiiere  are  no  bicuspids  in  the  deciduous  set,  the  molars 
being  of  full  molar  pattern  {n,  d). 

Fig.  30 


The  deciduous  teeth. 


The  deciduous  molars  of  both  jaws  are  of  irregular,  cjuadrangular 
form  on  the  morsal  surface,  diverging  rapidly  outward  to  the  neck, 
which  presents  a  large  buccal  ridge  .standing  out  at  the  margin  of  the 
enamel,  and  is  rounded  off  suddenly  to  the  neck,  which  is  much  con- 
tracted. This  thick  ridge  is  characteristic  of  the  deciduous  molars  and 
is  ab.sent  in  those  of  the  permanent  denture.  It  is  somewhat  more 
prominent  and  bulging  on  the  buccjal  than  on  the  other  faces.  In  ad- 
justing ferrule  crowns  to  these  teeth  the  gold  need  not  be  carried  beyond 
this  ridge,  but  burnished  over  it  slightly. 

The  morsal  surface  (e)  of  the  upper  deciduous  grinders  pre.sents  the 
characteristic  pattern  of  the  upper  molars,  four  tubercles,  oblicpie  ridges, 
etc.,  but  reduced  and  contracted.  A  distinctive  feature  is  that  the  mar- 
ginal ridges  and  angles  are  more  acute  and  sharp  than  in  the  perma- 
nent molars.  Sometimes  the  two  lingual  cusps  are  reduced  to  one  and 
the  lingual  border  is  rounded  and  crescentic. 


THE    VARIATIONS  OF  TOOTH   FORMS  53 

The  second  inolai-  is  lai'^vr  than  the  first  and  tlie  niorsal  surface  is 
wider. 

The  transverse  diameter  of  the  crowns  of  the  upper  molars  is  the 
longest. 

'J'lie  luurr  iiiolars  Ul)  are  similar  to  the  permanent  molars  in  pattern, 
but  are  more  irrei>;ular  as  to  the  contour  of  the  morsal  surface  (/). 
Tiie  tubercles  may  be  hi(>;her  than  in  the  upper  molars,  and  the  tri- 
angular ridges  more  marked.  The  central  fossa  maybe  large  and  wide, 
or  tlividetl  by  the  triangular  ridges.  The  second  molar  is  five-Iobed, 
unlike  the  second  permanent  molar,  which  has  but  four  cusps.  The 
morsal  face  is  decidedly  trapezoidal  in  outline,  the  mesio-distal  diameter 
beino-  greater  than  the  transverse. 

The  roofs  of  the  deciduous  molars  are  similar  to  those  of  the  other 
molars,  except  that  they  are  very  divergent  to  accommodate  the  crown 
of  the  advancing  bicuspids.  They  are  thin  and  long,  and  difficult  to 
enter  and  fill.  The  pulp  chamber  is  large  and  open  in  the  crown;  as 
a  consequence  of  this  caries  soon  reaches  the  pulp.  Treatment  and 
fillino-  of  the  canals  is  difficult  and  uncertain. 


THE  VARIATIONS  OF  TOOTH  FORMS 

The  teeth  mai/  vary  quite  extensively  from  the  typal  forms  which 
have  been  described,  and  these  variations  may  be  due  to  a  number  of 
causes.  Through  all  degrees  of  variation,  however,  the  type  is  still  pre- 
served, unless  the  tooth  form  is  cjuite  destroyed  by  pathological  causes. 

The  general  causes  of  variation  may  be  enumerated  as  follows- 

1.  Incompleteness  of  development. 

2.  Reversion  to  primitive  types. 

3.  Temperamental  impress. 

4.  Pathological  lesions. 

i.  Under  incompleteness  of  development  may  be  grouped  all  those 
varieties  of  stunted  growth  which  are  the  effect  of  disuse  and  the  con- 
sequent effort  of  Nature  to  reduce  and  suppress  the  teeth  as  useless 
parts.  The  third  molar  teeth  suffer  most  from  these  suppressive  attempts 
of  Nature  in  the  effort  toward  economy  of  growth;  next  to  these  teeth 
the  upper  lateral  incisors  are  most  frequently  affected  by  reduction  of 
size,  stunted  growth,  and  suppression.  Other  teeth  are  not  affected, 
or  but  very  slightly,  by  this  influence,  except  in  rare  cases. 

2.  Under  the  second  head,  reversion  to  primitive  types,  we  have  a 
variety  of  interesting  phenomena  in  the  form  of  parts  of  the  human 
teeth  which  seem  to  be  a  zoological  legacy.  These  consist  of  conspic- 
uous features  which  reappear  and  seem  to  recall  forms  of  the  teeth 
observed  in  some  of  the  lower  animal  orders,  especially  the  quadrumana 
and  insectivora. 


54  IIVMAX  ODONTOGRAI'IIY 

Ainon^  these  features  may  l)e  mentioned  the  curved  uj)[)er  central 
incisor  with  the  ])roniinent  cino;iile  on  the  lin^nial-huccal  ridoc,  niakin<,' 
a  notcli  whic-li  recalls  the  incisors  of  the  moles;  the  prominent  cinf,nile 
on  the  linoiial  face  of  the  lateral  incisor,  which  is  not  imcommon  and 
recalls  the  form  found  in  the  insectivora  and  some  of  the  (|uadrumana; 
the  extra  lonu',  curved  canine  with  extra  larnc  median  ridt^cs,  which 
recalls  the  larue  forms  of  this  tooth  in  the  hahoons  and  in  the  carnivora; 
the  double  root  sometimes  found  in  this  tooth  is  also  a  reversion  to  the 
insectivorous  type;  the  three-rooted  bicuspid  is  a  (|uadrmnanous  rever- 
sion; the  upper  tricuspid  molar  is  a  primitive  typal  form,  leadini^  Iniek 
to  the  lemurs  and  beyond  them  to  the  early  typal  mammals  found  in 
fossil  formations;  the  notched  and  grooved  incisor  recalls  the  divided 
incisor  of  the  galeopithecus;  the  double-j-ooted  lower  incisors  and  canines 
recall  insectivorous  forms;  the  unicuspid  lower  first  bicuspid  is  an  insect- 
ivorous type  and  is  often  quite  marked  in  man;  the  fifth  cusp  on  the 
lower  second  molar  is  a  cpuuh'umanous  reversion;  the  wrinkled  surface 
of  the  lower  tliird  molar  is  like  that  of  the  orang,  etc. 

There  are  other  features  that  might  be  named  illustrating  the  work- 
ings of  the  law  of  atavism,  by  which  parts  once  lost  in  evolution  may 
reappear  and  be  reproduced. 

3.  Under  the  third  head,  temperamental  impress,  may  be  noticed 
those  differences  of  form  and  structure  which  have  relation  to  the  domi- 
nant temperament  in  the  constitution  of  the  individual,  (ireat  difi'er- 
ences  exist  between  the  teeth  of  diiferent  persons,  and  these  are  mainly 
dictated  by  temperament. 

The  teeth  of  the  primary  basal  temperaments  present  the  following 
physical  peculiarities,  which  are  characteristic  of  the  particular  tempera- 
ment : 

The  bilious  temperament  presents  teeth  that  are  of  a  strong  yellow; 
large,  long,  and  angular,  often  with  transverse  lines  of  formation,  with- 
out brilliancy,  transparency,  and  of  but  slight  translucency;  firm  and 
close  set,  and  well  locked  in  articulation. 

The  sanguine  temperament  has  teeth  that  are  symmetrical  and  well 
proportioned,  with  curved  or  rounded  outlines,  and  round  cusps;  cream 
color,  inchned  to  yellow,  rather  brilliant  and  translucent;  well  set,  and 
occlusion  firm. 

The  nervous  temperament  has  teeth  which  are  rather  long,  the  cutting 
edges  and  cusps  long  and  fine;  color  pearl  blue  or  gray,  very  trans- 
parent at  the  apex;  the  occlusion  very  penetrating. 

The  lymphatic  temperament  presents  teeth  that  are  pallid  or  opaque, 
dull  or  muddy  in  coloring;  large,  broad,  ill  shaped,  cusps  low  and 
rounded;  the  occlusion  loose  and  flat. 

Of  the  binary  combinations: 

The  sanguitieo-bilious  has  teeth  which  are  large,  with  strong  edges 
and  large  cusps;  color  dark  yellow,  and  quality  good. 


THE   VARIATIOXS  OF   TOOTH   FORMH  55 

The  ncrvo-hUlous  lias  tcetli  that  are  \on^y  and  narrow,  with  long  cusps; 
color  yellowish  or  bluish,  or  both  combined;  the  enamel  stroni^,  the 
dentin  soft. 

The  lijmphu-hUious  has  teeth  that  are  laro^e,  with  thick  edt);es  and 
short  thick  cusps;  yellowish  in  color;  enamel  of  good  structure  and 
polish,  and  dentin  fair. 

The  hlUo-sangu'uicous  has  teeth  of  average  size,  round  arch,  well- 
developed  cusps  and  edges;  rich  dark-cream  color;  excellent  in  (juality. 

The  nervo-sanguiiicoiis  has  teeth  of  average  size,  good  shape,  round 
arch,  gootl  edges  and  cusps;  rich  cream  color;  enamel  and  dentin  of 
excellent  structure. 

The  lympho-sanguhu'oiis  has  teeth  of  more  than  average  size,  shapely 
edges  and  cusps,  rounded  arch;  color  grayish  cream;  enamel  and  dentin 
fairly  good. 

The  bilio-iicrvous  has  teeth  variable  in  size  and  form,  sometimes 
broad,  again  very  long  with  more  pointed  and  long  cusps;  the  color 
generally  bluish;  enamel  fairly  good,  dentin  soft  and  sensitive. 

The  sanguhieo-nervous  has  teeth  of  average  size,  good  shape,  round 
arch;  color  grayish  blue;  soft  and  frail. 

The  biUo-hjmphatic  has  teeth  usually  large,  with  thick  edges,  short, 
thick  cusps,  and  flat  arch;  color  yellowish;  quality  good. 

The  sangmnco-lijmphaiic  has  teeth  of  more  than  the  average  size, 
broad  round  arch;  color  gray;  enamel  and  dentin  poor. 

The  nervo-lymphatic  has  teeth  of  average  size,  good  shape,  average 
length,  rather  round  arch;  color  bluish  gray;  soft  and  poor. 

Combinations  of  the  binary  temperaments  are  of  the  most  common 
occurrence  in  individuals,  but  there  is  usually  one  basal  temperament 
that  preponderates  over  the  others  and  gives  its  characteristic  to  the 
teeth  as  a  predominating  influence. 

4,  Under  the  fourth  head,  pathological  lesions,  are  to  be  included 
all  those  disturbances  of  nutrition  which  eventuate  in  faulty  formation 
of  the  teeth,  whether  due  to  specific  hereditary  diseases,  mere  malnutri- 
tion, idiosyncrasies,  predispositions,  defective  functional  life,  etc.  But 
this  leads  beyond  the  province  of  this  chapter  into  the  field  of  special 
pathology  and  embryology. 


CHAPTER    II 

DENTAL  IIIST()L()(;Y  WITH  REFERENCE  TO  OPERATIVE 

DENTISTRY.^ 

By  FHEDERICK  B.  NOYES,  B.A.,  D.D.S. 

The  development  of  our  knowledoe  of  the  eell  has  had  a  most  pro- 
found effect  upon  the  entire  practice  of  medicine;  in  fact,  the  progress  of 
modern  medicine  dates  from  the  studies  of  cell  biology,  the  germ  theory  of 
disease  being  only  one  of  the  phases  of  this  development.  In  terms  of  the 
cell  theory  the  functions  of  the  body  are  but  the  manifest  expression  of 
the  activities  of  thousands  or  millions  of  more  or  less  independent  but 
correlated  centres  of  activity;  if  these  centres  or  cells  perform  their 
functions  correctly,  the  functions  of  the  body  are  normal;  but  if  they 
fail  to  perform  their  office,  or  work  abnormally,  the  functions  of  the 
body  are  perverted.  In  the  last  analysis,  then,  all  physiology  is  cell 
physiology;  all  pathology  cell  pathology.  To  modern  medicine  his- 
tology, or  the  cell  structm-e  of  the  organs  and  tissues  of  the  body, 
together  with  cell  physiology,  is  the  rational  foundation  of  all  practice. 
This  is  as  true  for  the  dentist  as  for  the  physician  so  far  as  regards  all 
of  the  soft  tissues  of  the  mouth  and  teeth  that  he  is  called  upon  to  treat 
and  handle.  With  caries  of  the  teeth,  the  disease  which  most  demands 
the  attention  of  the  dentist,  the  case  is  somewhat  different.  Caries 
of  the  teeth  is  an  active  destruction,  by  outside  agencies,  of  formed 
materials  which  are  the  result  of  cell  activity  (the  tissues  themselves 
being  passive).  The  cellular  activities  of  organs  and  tissues  of  the 
body  may  have  an  influence,  but  this  is  only  in  producing  those  con- 
ditions of  environment  which  render  the  acdvities  of  the  destructive 
agents  efficient  in  their  action  upon  tooth  tissues.  Though  the  enamel 
and  dentin  are  passive,  we  can  understand  the  phenomena  of  caries 
only  as  we  understand  the  structure  of  the  tissues;  and  not  only  must 
the  treatment  of  caries  be  based  upon  a  knowledge  of  the  structure 
of  the  tissues,  but  the  mechanical  execution  of  the  treatment  is  facili- 
tated by  that  knowledge.  In  the  preparation  of  cavities  the  arrange- 
ment of  the  enamel  wall  is  determined  by  our  knowledge  of  the  direction 
of  enamel  prisms  in  that  locality,  and  to  a  certain  extent  the  position 
of  the  cavity  margins  must  be  governed  by  our  knowledge  of  the  structure 

'  In  the  prep.aration  of  this  material  I  am  indebted  to  Or.  O.  V.  Bhick  for  the  use  of  his  large 
and  valuable  collection  of  microscopic  slides,  and  for  much  advice  and  many  suggestions. 

(56) 


DENTAL  HISTOLOGY  AND  OPERATIVE  DENTISTRY  57 

of  the  enamel.  Jn  the  execution  of  the  work  a  mniute  knowledge  of  the 
direction  of  enamel  rods  becomes  the  most  important  ("lemcnt  in  rapiditv 
and  success  of  operation. 

From  the  standpoint  of  comparative  anatomy,  the  teeth  are  found 
to  be  not  a  part  of  the  osseous  system,  but  appendatijes  of  the  skin, 
and  are  to  be  compared  with  such  structures  in  the  body  as  the  nails 
and  the  hair.  The  teeth  are  a  part  of  the  exoskeleton,  and  their  rela- 
tion to  the  bones  of  the  endoskeleton  is  entirely  secondary,  for  the  pur- 
pose of  strength,  the  bone  growing  up  around  the  tooth  to  support  it. 

If  we  examine  the  skin  of  such  an  animal  as  the  shark,  we  find  the 
entire  surface  covered  with  small  calcified  bodies  which  are  really 
small  simple  cone-shaped  teeth      The  mouth  cavity  is  to  be  regaixled, 


Fig.  31 


Shark's  skull  (Lamna  eornubica),  showing  succession  of  teeth. 


when  viewed  in  the  light  of  its  development,  as  a  part  of  the  outside 
surface  of  the  body  which  has  been  enclosed  by  the  development  of  the 
neighboring  parts,  and  the  dermal  scales  or  rudimentary  teeth  which 
were  found  in  the  skin  covering  the  arches  which  form  the  jaws  have 
undergone  special  development  for  the  purposes  of  seizing  and  masti- 
cating the  food.  In  the  simplest  forms  there  is  only  a  development 
in  size  and  shape  of  these  scales,  and  they  are  supported  only  by  the 
connective  tissue  which  underlies  the  skin.  These  teeth  are  easily  torn 
off  in  the  attempt  to  hold  a  resisting  prey,  and,  as  in  the  shark,  they  are 
constantly  being  replaced  by  new  ones  (Fig.  31).  In  the  more  highly 
developed  forms  there  is  a  growth  of  the  bone  of  the  arch  forming  the  jaw 
upward  around  the  bases  of  these  scale-like  teeth,  to  support  them 
more  firmly  and  render  them  more  useful. 


58 


DEXTAL  HISTOLOGY  AXD  OI'ERATIVE  DEXTISTRY 


If  we  coinparc  the  structure  of  the  liiiir  with  that  c)f  the  tooth,  we 
find,  \\\  the  ease  of  the  hair,  a  horny  structure  eouipose*!  of  ('jjithehal 
cells  restini^  uj)on  a  paj)illa  of  couueetive  tissue;  in  the  ease  of  the  tooth, 
a  calcified  structure  formed  by  epithelial  cells  resting;  upon  a  j)apilla 
of  coiuiective  tissue  which  is  also  j>artially  cah-ified. 

The  relation  of  the  hones  of  the  jaws  to  tiie  teeth  is  entirely  a  secondary 
and  transient  one.  The  hone  ^rows  up  around  the  roots  of  the  teetii  to 
support  them,  and  is  destroyed  and  removed  with  the  loss  of  the  teetli 
or  the  cessation  of  their  function.     In  this  way  the  development  of  the 


Fig.  32 


m.  ^  te.  jft.      ^w 


Changes  in  the  mandible  with  age;  buccal  and  lingual  view. 

alveolar  proce.s.s  takes  place  around  the  temporary  teeth;  all  of  this  hone 
surroundint]^  their  roots  is  absorbed  and  removed  with  the  lo.ss  of  the 
temporary  dentition,  and  a  new  alveolar  process  grows  up  around  the 
roots  of  the  permanent  teeth  as  they  are  formed.  This  development  of 
bone  around  the  roots  of  the  teeth  leads  to  the  changes  in  the  shape  of 
the  body  of  the  lower  jaw,  increasing  the  thickness  al)ove  the  mental 
foramen  and  the  inferior  dental  canal.  Wiien  the  teetli  are  finally  lost 
this  bone  is  again  removed  and  the  body  of  the  jaw  is  reduced  in  thick- 
ness from  above  downward  ( F'ig.  32).  These  phenomena  are  of  im- 
portance in  their  bearing  upon  the  causes  and  treatment  of  diseased 
conditions  of  the  teeth,  particularly  those  which  involve  the  supporting 
tissues. 


ENAMEL  59 

Dental  Tissues. — The  human  tci'tli  ai-c  made  up  of  four  tissues 
(Fio-.^:«): 

1.  'i'lio  cudiiicl  covers  tlie  exposed  j)ortioii  of  the  tooth,  oi-  ci-owii, 
and  i>;ives  the  detail  of  crown  form.  Its  function  is  to  jjrotect  the  tooth 
against  the  wear  of  friction. 

2.  The  dentin  forms  the  mass  of  the  tooth  and  determines  its  chiss 
form,  the  number  of  cusps  and  the  number  of  roots  beinn;  indicalcd  by 
the  dentin  form. 

'>].  Cemcnium  covers  the  dentin  beyond  tlie  border  of  the  enamel, 
overlapping  it  slightly  at  the  gingival  line  and  forming  tlie  surface  of 
the  root.  Its  function  is  to  furnish  the  attachment  of  the  fibers  of  the 
peridental  membrane,  which  fastens  the  tooth  to  the  bone. 

4.  The  pu/p,  or  soft  tissue,  filling  the  central  cavity  in  the  dentin 
is  the  remains  of  the  formative  organ  which  has  given  rise  to  the  dentin. 
Its  functions  are  the  formation  of  dentin  and  a  sensory  function. 

In  describing  the  structure  of  the  teeth  and  the  arrangement  of  the 
structural  elements  of  the  tissues  directions  are  described  with  reference 
to  three  planes: 

The  mesio-disto-axial  plane,  a  plane  passing  through  the  centre  of  the 
crown  from  mesial  to  distal  and  parallel  with  the  long  axis  of  the  tooth. 

The  bucco-linguo-axial  plane,  a  plane  passing  through  the  centre  of 
the  crown  from  buccal  to  lingual  and  parallel  with  the  long  axis  of  the 
tooth. 

The  horizontal  plane,  at  right  angles  to  the  axial  planes. 

The  Supporting  Tissues. — The  human  teeth  are  supported  on  the 
maxillary  bones,  their  alveolar  processes  growing  up  around  the  roots  of 
the  teeth,  so  that  the  roots  fit  into  the  holes  in  the  bone.  The  calcified 
structures  of  the  tooth  and  the  bone  are  not,  however,  united,  but  the 
roots  are  surrounded  by  a  fibrous  membrane,  the  peridenfal  membrane, 
or  pericementum,  which  fastens  the  tooth  to  the  bone. 


ENAMEL 

The  enamel  differs  from  all  other  calcified  tissues  in  the  nature  of 
the  structural  elements  of  which  this  tissue  is  made  up,  in  the  degree 
of  calcification,  and  in  origin,  being  the  only  calcified  tissue  derived 
from  the  epiblast. 

The  enamel  is  formed  from  an  epithelial  organ  derived  from  the 
epithelium  of  the  mouth  cavity  and  indirectly  from  the  epiblastic  germ 
layer,  w^hile  all  other  calcified  tissues  are  products  of  the  mesoblast. 
In  the  case  of  bone  and  dentin  the  formative  tissue  is  persistent.  It 
is  possible  in  bone  at  least,  therefore,  to  have  degenerative  and  regen- 
erative changes,  or  the  removal  of  part  of  the  calcium  salts  and  their 
replacement  through  the  agency  of  the  formative  tissue;  while  in  the 


()()  DKXTAL  IJlSTOLOaV  AXJ)  OI'KRATIVK   DEXTISTRY 

Vw.  33 


Ground  section  of  :i  canine:  E,  enamel;  Cm,  cementum;  D,  dentin;  Pc,  pulp  chamber;  De, 
dento-enamel  junction;  Ed,  enamel  defect;  G.  junction  of  enamel  and  cementum  at  the  gingival 
line;  Gt,  granular  layer  of  Tomes.     (Reduced  from  photoniicrograph  made  in  three  sections.) 


ENAMEL  (31 

fiKiiiirl  no  Mich  ro^ciu'rativt'  chaiigv  is  possiMc,  as  flic  Formative  tissue 
clisapiH'arcd  when  (he  tissue  was  eoinpleti-d  and  heforc  the  eruption  of 
the  tooth. 

The  enamel  is  the  hardest  oF  human  tissues.  Chemicallv  it  is  ecMii- 
posed  of  the  pliosphates  and  earhonates  of  calcium  and  ma<,niesium  and 
a  very  small  amount  of  the  fluorides,  water,  also  a  very  small  amount 
of  organic  matter  if  any.^  The  enamel  in  the  natural  condition,  hathed 
in  the  fluids  of  the  mouth,  contains  a  considerable  amount  of  water. 
If  dried  at  a  litUe  above  the  boiling  point  of  water,  it  gives  up  part 
of  it  and  shrinks  considerably,  so  as  to  crack  in  fine  checks.  If  heated 
almost  to  redness,  it  suddenly  giyes  of¥  from  3  to  5  per  cent,  (of  the 
dry  weight)  of  water  with  almost  explosiye  violence.  These  facts  were 
demonstrated  some  years  ago  by  Charles  Tomes,^  and  account  for  most 
of  what  was  formerly  recorded  as  organic  matter  in  old  analyses. 

If  we  observe  under  the  microscope  the  action  of  acids  upon  thin 
sections  of  enamel,  when  the  inorganic  salts  are  entirely  removed,  the 
structure  of  the  tissue  vanishes,  there  being  no  trace  of  organic  matrix 
left  as  in  the  case  of  bone  or  dentin.  In  the  growth  of  bone  and  den- 
tin the  formative  tissue  produces  first  an  organic  matrix  in  the  form 
of  the  tissue,  and  into  this  the  inorganic  salts  are  deposited,  combining 
with  the  organic  substances  of  the  matrix.  This  union  is  compara- 
tively weak,  howev^er,  for  by  the  action  of  acids  the  combination  is 
broken  up  and  the  inorganic  salts  are  dissolved;  or  by  heat  the  organic 
matter  is  removed,  and  in  either  case  the  form  of  the  tissue  will  be 
maintained. 

In  the  case  of  the  enamel,  the  formative  organ  produces  organic 
substances  containing  inorganic  salts,  and  the  substances  are  arranged 
in  the  form  of  the  tissue  after  the  manner  of  a  matrix;  but  finally  under 
the  action  of  the  formative  organ  all  of  the  organic  matter  is  remo.\ed 
and  substituted  by  inorganic  salts,  whatever  organic  matter  is  found  in 
the  fully  formed  tissue  being  the  result  of  imperfect  execution  of  the 
plan. 

The  enamel  is  composed  of  two  structural  elements,  the  enamel  rods, 
or  prisms,  sometimes  called  enamel  fibers,  and  the  inferprismatic  or 
cementing  substance,  both  of  which  are  calcified.  It  is  to  the  arrange- 
ment of  these  structural  elements  that  the  characteristics  of  the  tissue 
with  which  we  are  most  concerned  in  operative  procedures  are  due. 

1  Von  Bibra  gives  the  following  analysis  of  enamel: 

Calcium  phosphate  and  fiuorid S9.82 

Calcimn  carbonate 4.37 

Magnesium  phosphate 1 .  34 

Other  salts 0.88 

Cartilage 3.39 

Fat 0.20 

Total  organic 3.r>9 

Total  inorganic 96.41 

-  Journal  of  Physiology,  1896, 


02 


DESTAL   HISTOLOGY  AND  Ol'EI{ATI\  E   DE.XTISTRY 


Wliile  both  the  prisnis  and  intcrprisinatic  .sul).stance  of  tlic  enamel 
are  ealciiied,  or,  lietter,  eoinposed  of  iiior<ranie  salts,  the  two  substances — 
that  is,  the  substance  of  the  rods  and  the  substance  between  the  rods 
— show  markedly  different  properties  both  chemical  and  physical.  If 
treated  with  acid,  the  interj)risniatic  substance  is  acted  upon  more 
rapidly  than  the  rods,  so  that  the  latter  become  more  conspicuous.  By 
this  means  sections  of  the  enamel  may  be  etched  to  render  it  easier  to 
study  the  direction  and  arrangement  of  the  rods.  If  the  action  of  the 
acid  is  carried  far  enough,  the  rods  will  fall  apart  before  they  are  them- 
selves entirely  dissolved.  Fig.  34  is  from  the  debris  in  a  carious  cavity, 
and  shows  rods  isolated  by  the  action  of  the  acids  of  caries. 


rv:.  rn 


Enamel  rods  isolated  by  caries.    (About  465  X) 


The  interprismatic  substance  is  not  as  strong  as  the  rods,  so  that  in 
splitting  or  breaking  the  enamel  the  tissue  separates  on  the  lines  of  the 
cementing  substance,  occasionally  breaking  across  a  few  rods  but  fol- 
lowing their  general  direction,  the  lines  running  between  rods,  not  at 
their  centres. 

In  cleaving  the  enamel  the  chisel  does  not  enter  the  tissue  sepa- 
rating rod  from  rod,  but  the  edge  engages  with  the  surface,  and  the 
force  applied  at  an  acute  angle  with  the  direction  of  the  rods  fractures 
the  tissue  in  the  lines  of  least  resistance.  If  the  edge  be  keenly  sharp, 
it  will  enter  the  tissue  slightly,  and  then  the  bevel  acts  as  a  wedge  in 
addition  to  the  force  applied  to  the  shaft  of  the  instrument;  but  if  the 
edge  be  dull,  it  will  rest  across  the  ends  of  many  rods,  will  not  engage 
with  the  surface,  and  the  force  applied  will  break  and  crumble  the 
tissue,  but  will  not  cleave  it. 


ENAMEL  63 

The  enamel  rods,  or  prisms,  are  long,  slender  prismatic  rods  or 
fibers,  five-  or  six-sided,  pointed  at  both  ends,  and  alternately  expanded 
and  constricted  throughout  their  length.  Tiiey  are  from  3.4  to  4.5 
microns'  in  diameter,  some  of  them  apparently  reaching  the  entire 
distance  from  the  surface  of  the  dentin  to  the  surface  of  the  enamel;  but 
as  the  diameter  of  the  rods  is  the  same  at  their  outer  and  inner  ends, 
and  as  the  crown  surface  is  much  greater  than  the  surface  of  dentin 
covered  by  enamel,  there  are  many  rods  which  do  not  extend  through 
the  entire  thickness.  These  short  rods  end  in  tapering  points  between 
the  converging  rods  which  extend  the  entire  distance.  To  express 
this  in  terms  of  development:  as  the  formation  of  enamel  begins  at 
the  surface  of  the  dentin,  the  increasing  area  of  crown  surface  recjuires 
more  ameloblasts,  and  as  new  ameloblasts  take  their  place  in  the  layer 
the  formation  of  new  enamel  rods  begins  between  the  rods  which  were 
previously  forming.  These  short  rods  are  most  numerous  over  the 
marginal  ridges  and  at  the  points  of  the  cusps,  and  will  be  considered 
more  fully  in  connection  with  those  positions. 

In  ground  sections  cut  at  right  angles  to  the  direction  of  the  rods^ 
the  tissue  has  the  appearance  of  a  mosaic  floor,  the  outline  of  the  rods 
being  more  distinct  if  they  have  been  marked  out  by  treating  the  section 
slightly  with  acid  (Fig.  35).  In  longitudinal  sections  (Fig.  36)  the  sides 
of  the  rods  are  not  smooth  and  even  like  the  sides  of  a  lead  pencil,  but 
are  alternately  expanded  and  constricted.  They  are  well  illustrated  by 
taking  balls  of  soft  clay  and  sticking  them  together  one  above  another 
to  form  a  rod,  then  putting  a  number  of  rods  together  so  that  by  mutual 
pressure  they  take  hexagonal  forms.  This  illustrates  also  the  manner 
of  growth  of  the  tissue  in  formation.  The  expansions  and  constrictions 
can  be  seen  in  rods  that  have  been  scraped  from  a  cleaved  surface  of 
enamel,  but  better  by  isolating  rods  by  the  slight  action  of  dilute  acid 
(Fig.  37). 

In  the  construction  of  the  tissue  the  rods  are  so  arranged  that  the 
expansions  of  one  rod  come  opposite  to  the  expansions  in  the  adjoining 
rods,  and  do  not  interlock  with  their  constrictions.  This  arrangement 
leaves  alternately  a  greater  and  a  less  amount  of  cementing  substance 
between  them. 

When  observed  under  the  microscope,  the  enamel  rods  show  a  char- 
acteristic appearance  of  light  and  dark  lines  running  across  them. 
These  markings  are  similar  to  the  striations  of  voluntar}^  muscle  fibers, 
and  are  described  as  the  striation  of  the  enamel.  It  is  seen  not  only  in 
isolated  rods  (Fig.  34),  but  also  in  sections  ground  in  their  direction  (Fig. 
38).    This  appearance  of  striation  in  the  enamel  is  caused  by  the  alter- 

'  A  micron  is  the  unit  of  microscopic  measurement,  and  is  equal  to  one  one-thousandth  of  a 
millimeter. 

'■'  In  describing  the  direction  of  enamel  rods  they  are  always  considered  as  extending  from  the 
dentin  to  the  surface,  and  the  angle  is  formed  at  the  surface  of  the  dentin  with  the  locating  plane, 
either  horizontal  or  axial. 


1)4 


DKXTAL   IIISTOLoay   AM)  Ol'ERATIVE   DESTISTKY 


nate  expansions  and  constrictions  of  the  rods  refracting  the  hght  Hke  a 
lens.    In  sections  the  expansions  in  adjoining  rods  are  opposite  to  each 


Fiu.  35 


Transverse  section  of  enamel  rods.     (About  80  X) 

other,  the  difference  in  the  refracting  power  of  the  prismatic  and  inter- 
prismatic  substances  producing  the  same  effect. 


Fig.  36 


Enamel  rods  in  fhiii  etohed  section,     (.\bout  800  X) 

The  appearance  of  striation  is  the  record  in  the  fully  formed  tissue 
of  the  manner  of  growth,  each  dark  sti-ipe,  or  expansion,  in  a  rod  repre- 


ENAMEL 


65 


sontiiifj^    a    (;'li»l)iile    of    j)iir(ially    calcified    niatcriiil.      The    aiiicloblu.st.s 
build  up  the  rods  In   the  addition  of  globule  after  olohnle,  .surroundiufr 


Ki.i.  37 


Enamel  rods  isolated  by  scraping.     (About  800  X) 

them  with  a  cementing  substance  and  completing  the  calcification  of 
both.  In  this  sense  the  striation  of  the  enamel  may  be  said  to  record 
the  ffrowth  of  the  individual  rods. 


Fig.  38 


Enamel  showing  striation.     (About  1000  X) 

While  the  enamel  is  a  very  hard  substance  when  its  structure  is  com- 
plete and  perfect,  its  most  striking  physical  characteristic  is  a  tendency 
5 


66 


DENTAL  HISTOLOdY  ASD  Ol'ERATIVE  DENTISTRY 


to  split  or  crack  in  the  direction  of  its  structural  elements  wlieii  a  hreak 
has  been  made  in  the  tissue.  While  it  is  difhcuU  to  cut  across  the  rods 
or  make  an  oj)eiiin<i-  on  a  j)erfect  surface,  if  a  hreak  lias  been  established 
it  is  c()mj)aratively  easy  to  split  olV  the  tissue  from  the  sides  of  the  ()peniii<; 
when  the  rods  lie  parallel  with  each  othci".  V'v^.  W.)  shows  a  held  of 
enamel  illustratinijj  the  way  in  which  the  tissue  splits  or  clea\es  in  the 
direction  of  the  rods. 

Upon  the  axial  surfaces  the  enamel  rods  are  usually  straight  and 
parallel  with  each  other,  except  where  there  has  been  some  Haw  or 
distiu'bance  in  development;  but  upon  the  occlusal  surface,  altliou<^h 
sometimes  straight,  they  are  very  often  much  twisted  and  wound  around 
each  other,  especially  at  their  iimer  ends.    This  diifercnce  in  the  arranj^e- 


Viv..  39 


' 

• 

^^ 

Mgtt 

Uf^^^n 

H 

,:««'^^ 

H 

^H<^??r^ 

'  '^^1 

■-'            *        % 

Wf 

" 

\ 

''1 

s 

::U 

LJj,_.'-->±^_-_ 

" 

1 

•.i^iv  ■'■ 

1 

Hj 

—lii^^H 

'k=L^. 

■        -^^J.-                                            '-     '■      ■ 

....-l— 

IWBi 

H 

Enamel  showing  direction  of  cleavage.     (About  70  X) 


ment  of  the  rods  causes  the  greatest  difference  in  the  feeling  of  the 
tissue  under  cutting  instruments.  Such  a  specimen  of  enamel  as  shown 
in  Fig.  40  can  be  cut  away  easily,  the  tissue  breaking  through  to  the 
dentin  and  splitting  off  in  chunks;  while  a  specimen  like  Figs.  41  and 
42  wiD  not  cleave  if  supported  upon  sound  dentin.  If  the  outer  ends 
of  the  rods  are  straight,  they  will  split  part  way  to  the  dentin  (Fig.  42); 
but  where  they  begin  to  twist  around  each  other  they  will  break  across 
the  rods.  If  the  dentin  is  removed  from  under  such  enamel,  it  will 
break  in  an  irregular  way  through  the  gnarled  portion. 

From  a  study  of  the  arrangement  of  the  enamel  rods  in  the  forma- 
tion of  the  crow'n  it  is  apparent  that  the  plan  is  such  as  to  give  the  greatest 
strength  to  the  perfect  structure,  and  may  be  likened  to  an  arch.  At 
the  gingival  border  the  rods  are  short  and  are  inclined  apically  G  to  10 


07 


Straight  enamel  rods.     (About  80  X) 

Vin,    11 


Gnarled  enamel.     (About  80  X) 


68 


DENTAI.   UlSTOLOCY  AND  Ol'Kli  AT  I  V  l<:   DhWTISTh'V 


ceiitifrrades'  (20  to  o5  det-rccs)  from  the  horizontal  phme.  'i'liese  short 
rods  lire  overlapped  for  a  short  dkstance  by  theceinentuin.  This  inclination 
grows  less  and  less,  and  at  some  place  in  the  ginf>;ival  half  of  the  middle 
third  of  the  surface  they  are  in  the  horizontal  plane.     Al  this  jjoini  they 


Fig.  42 


Gnarled  enamel.    (About  SOX  ) 


are  also  usually  perpendicular  to  the  surface  of  the  dentin.  Passing 
from  this  point  they  become  inclined  more  and  more  occlusally  from  the 
horizontal  plane,  at  the  junction  of  the  occlusal  and  middle  thirds  about  8 
to  12  centigrades  (28  to  40  tlegrees)  in  bicuspids  and  molars,  and  8  to  18 
centigrades  (28  to  65  degrees)  in  incisors  and  canines.    In  the  occlusal  third 


'  In  the  centigrade  division  the  circle  is 
divided  into  one  hundred  parts,  each  calleil 
a  centigrade.  One  centigrade  is  equal  to  .'^.f) 
degrees  of  the  astronomical  circle,  25  centi- 
grades to  90  degrees,  12  centigrades  to  4.5 
degrees.  The  cut  gives  a  comparison  of  the 
two  systems  of  measuring  angles. 


2  70 


180 
Centigrade  division. 


EN  A  MEL 


69 


the  inclination  increases  rapidly,  and  often  the  outer  ends  of  the  rods 
are  inclined  more  Uian  the  inner  ends.  Over  the  point  oF  the  cnsps 
and  the  crest  of  the  marginal  rid<>es  the  rods  reach  tlu-  axial  plane, 
though  they  are  often  very  nnich  twisted  about  each  other  in  the  inner 
half  of  their  length.  This  j)()sition  does  not  always  correspond  with  the 
highest  point  of  the  cusp,  but  is  inclined  slightly  axially  from  that  posi- 
tion, and  corresponds  with  the  highest  j)oint  of  the  dentin  cusp. 


Fig.  43 


Diagram  of  enamel  rod  directions,  from  aphotograph  of  a  bucco-lingiial  section  of  an  upper  biscupid. 


Passing  down  the  central  slope  of  the  cusp,  or  ridge,  the  rods  become 
again  inclined  away  from  the  axial  plane  toward  the  groove,  or  pit, 
leaning  toward  each  other  where  the  two  plates  meet.  The  degree  of 
inclination  of  the  rods  on  the  central  slope  of  the  cusps  depends  upon  the 
height  of  the  cusps;  the  higher  the  cusp  the  greater  the  inclination  from 
the  axial  plane.  Fig.  43,  a  diagram  from  a  photograph  of  a  bucco- 
lingual  section  of  an  upper  bicuspid  shows  the  plan  of  arrangement  and 
illustrates  the  arch  principle  in  the  construction. 

In  the  study  of  longitudinal  sections  of  the  teeth,  one  of  the  most 
conspicuous  structural  features  is  the  stratification  bands,  or  brown 
bands  of  Retzius.  These  bands  are  not  parallel  with  either  the  outer 
surface  of  the  enamel  or  the  dento-enamel  junction.  They  begin  at  the 
tip  of  the  dentin  cusps  and  sweep  around  in  larger  and  larger  zones. 


70 


DENTAL  IIISrOLOGY  AND  OPERATIVE  DENTISTRY 


These  stratification  bands  are  better  seen  in  comparatively  tliick  sec- 
tions, and  are  caused  by  the  varying  amount  of  pio^incnt  (lej)osited  with 
die  calcium  salts  in  the  development  of  the  tissue.  'I'hev  record  the 
growth  of  enamel  of  the  crown  as  a  whole,  as  each  line  was  at  one  time 
the  surface  of  the  enamel  cap.  These  stratifications,  or,  better,  incre- 
mental lines,  are  shown  in  Figs.  44  to  40. 


Fig.  44 


Stratification  of  enamel;   the  cusp  of  a  biscupid:  De,  dento-enamel   junction;   Ed.  enamel  defect 
showing  in  the  heavy  stratification  band;  I<i,  interglobular  spaces  in  the  dentin.     (.\bout40X) 

At  the  time  the  rod  at  A  (Fig.  45)  was  completely  formed  the  rod  at 
B  was  just  l)eginning  to  form  at  its  dentinal  end.  From  this  it  would 
seem  that  any  structural  defect  dwe  to  imperfect  development  would  not 
follow  the  direction  of  the  enamel  rods  from  the  surface  to  the  dentin, 
but  would  follow  the  stratification  lines;  and  if  these  structural  defects 
influenced  the  penetration  of  caries,  we  should  expect  to  have  the  direc- 
tion of  penetration  modified.     Fig.  44  shows  a  structural  defect  in  the 


ENAMEL 


71 


enamel  over  a  cusp  foUowino-  the  stratification  hand,  and  it  will  he 
noticed  also  that  there  is  a  structural  defect  in  the  dentin  at  a  corre- 
sponding position. 

Fin.    in 


Incisor  tip  showing  stratififation  or  incremental  lines.      Rods  at  .4  were  fully  formed  at  the 
time  the  rods  at  B  were  beginning  to  form.       (About  50  X) 


HISTOLOGICAL  REQUIREMENTS  FOR  STRENGTH  IN  ENAMEL 

WALLS 


1.  The  enamel  must  be  supported  upon  sound  dentin. 

2.  The  rods  which  form  the  cavosurface  angle  must  run  uninter- 
ruptedly to  the  dentin  and  be  supported  by  short  rods,  with  their  inner 
ends  resting  on  the  dentin  and  their  outer  ends  abutting  upon  the  cavity 
wall,  where  they  will  be  covered  in  by  the  filling  material. 

3.  That  the  cavosurface  angle  be  cut  in  such  a  way  as  not  to  expose 
the  ends  of  the  rods  to  fracture  in  condensing  the  filling  material  against 
them. 

The  first  step,  then,  in  the  preparation  of  an  enamel  wall  is  to  deter- 


72 


DENTAL  HLSTOLOGY  AND  OriHRATJVE  DENTISTRY 


luiiK'  the  direction  of  [\iv  eiuuiifl  rods  by  cleavage  with   a  chisel    or 
luitcliet. 

In  Figs.  47  and  4S,  No.  1  shows  an  enamel  wall  after  cleaving  the 
enamel  witli  a  hatchet.  It  will  he  noticed  that  the  split  has  not  followed 
the  direction  of  the  rods  exactly,  bnt  has  broken  across  them,  slivering  the 
rods  as  wood  slivers  in  splitting.  This  would  cause  in  the  cut  surface 
a  whitish,  opaque  appearance.  The  plane  of  tiie  enamel  wall  should  be 
extended  so  as  to  form  a  small  angle  with  the  plane  of  the  dentin  wall, 
by  shaving  the  surface  with  a  very  sharp  hand  instrument.  No.  2  shows 
the  same  wall  after  it  has  been  extended  somewhat;  but  it  will  be  seen 
that  it  has  not  been  extended  enough,  for  the  rods  forming  the  sur- 
face at  .1  do  not  reach  the  dentin,  but  run  out  at  B  on  the  cavity  wall, 
and  that  piece  would  chip  out  in  packing  against  it  or  if  force  camc^  upon 

Fig.  46 


Enamel  showing  both  striatioii  and  stratification.     (About  80  X) 


the  surface  afterward.  The  angle  should  be  extended  so  as  to  produce 
the  plane  shown  in  No.  'A;  then  the  cavosurface  angle  may  or  may  not 
be  bevelled  as  the  position  demands. 

In  some  positions,  as  on  the  axial  surfaces,  it  is  not  possible  to  ex- 
tend the  plane  of  the  entire  enamel  wall  as  described;  all  that  can  be 
done  is  to  shave  the  cut  surface,  leaving  the  wall  in  the  direction  of  the 
enamel  rods,  and  then  the  margin  is  strengthened  by  bevelling  the  cavo- 
surface angle,  so  that  the  rods  forming  the  margin  are  supported  by  at 
least  a  few  rods  which  are  covered  by  filling  material. 

In  cutting  out  the  fissures  on  the  occlusal  surfaces  of  molars  and 
bicuspids,  the  rods  are  inclined  centrally  from  the  axial  plane,  as  seen 
in  Fig,  49.  In  opening  a  fissure  the  lines  of  cleavage  will  not  be  in 
the  axial  plane,  but  sloping  inward  toward  the  body  of  the  cusp,  in  the 


HISTOLOaiCAL   REQCf REMENTS  IN  ENAMEL   ]r.W./>N         73 


74  DENTAL  HISTOLOGY  AND  OPERATIVE  DENTISTRY 


Preparatiou  uf  unauiel  wall  in  snarled  enamel :  1.  Knnmel  wail  as  el-aved,  shnwinpr  breaking 
across  rods  and  sliverintj  at  a.  J.  Wall  as  smoothed  but  not  extended  to  reniov  short  rods 
whose  inner  ends  are  cut  off  at  /-.  :>..  Wall  extended  and  trimmed  to  a  i^osition  of  strength. 
D,  dentin;  /)e,  dento-enamel  junction  :  <•,  cavo-surface  angle;  6,  point  where  inner  ends  of 
rods  are  cut  off;  a,  sliveriiii,'  of  the  tissue.    (About  80  <.) 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL   WALLS         75 

direction  indicated  hv  the  direction  of  the  cracks  in  Fitr.  49.  'i'lic  outer 
ends  of  the  enamel  rods  must  he  sha\'ed  away,  to  hrinn-  the  j)hiiie  of 
the  enamel  wall  parallel  with  the  dentin  wall  or  into  the  axial  plane. 
When  this  has  been  done  a  strong  margin  has  been  formed,  for  the 
rods  which  form  the  point  of  die  cavosurface  angle  are  snpported  by 
the  piece  A,  B,  C  (Fig.  50),  made  up  of  rods  resting  upon  sound  dentin 


Fig.  49 


Occlusal  fissure  in  an  upper  bicuspid,  showing  direction  of  rods.      (About  80  X) 

and  covered  by  the  filhng  material.  Often  the  angle  will  be  too  sharp, 
however,  and  the  cavosurface  angle  should  usually  be  bevelled  to  pro- 
tect the  margin  from  accident.  This  illustration  may  be  taken  as 
typical  of  occlusal  cavities. 

Fig.  51  shows  a  cavity  prepared  in  the  buccal  surface  of  an  upper 
molar.  The  occlusal  margin  is  placed  in  the  occlusal  half  of  the  middle 
third,  and  the  gingival  margin  in  the  gingival  half  of  the  gingival  third 


76 


DENT  A  I.   lllsrOLOaV   AM)  OPERATIVE   DENTISTRY 


of  the  surface.  In  the  occhisal  wall  (lie  nids  an-  incliiK-d  occhisally 
about 8  centi^rrades  ( 2S  dcirrccs)  from  the  lioii/.oiilal  |)laiK-.  After  cleav- 
iiifj^,  the  broken  and  sHvered  rods  should  be  shaved  away,  but  the  an^de 
cannot  be  increased  without  makin^^  the  margin  of  fiUing  material  too 


Yir..   50 


I 


/ 


:\^^A  J 


Preparation  of  enamel  walls  in  occlusal  fissure  cavities  (the  same  as  Fig.  49). 


thin ;  the  rods  forming  the  mart^in  shouhl  tiierefore  be  protected  by  bevel- 
iintj  the  cavosurface  angle.  At  the  gingival  wall  the  rods  are  inclined 
apically  from  the  horizontal  plane  about  6  centigrades  (20  degrees).  The 
wall  should  be  shaved  in  that  plane,  increasing  the  angle  a  little,  and 
the  cavosurface  angle  should  be  bevelled.     Fig.  52  shows  the  occlusal 


IIISTOLOCICAL    h'KQl/h'KMK.XTS   J .\   EXAMKL    WALLS         77 


Fig.  51 


Preparation  of  enamel  walls  in  a  buccal  cavity  in  a  molar:  (?,  gingival  wall;  0,  occlusal  wall 

(About  70  X.) 


78 


DKXTAL   IIIST()L(H;Y  AM)  OI'KHAriVK   DICXTISTRY 


enamel  wall  alone,  after  cleavintj  and  triinniin^r  into  form.     Sueli  enamel 
walls  may  be  taken  as  typical  of  axial  siuface  cavities,  the  angle  of  the 


Fi<;.  5 


2.   Wall  OS  trimmed. 
Preparation  of  occlusal  wall  of  Fig.  .51.     (.-Miout  70  X  ) 


enamel  with  the  dentin  wall  being  determined  by  the  direction  of  the 
enamel  rods  in  the  position  where  the  margin  is  laid. 

Grooves,   fissures,  and  pits  are  always  positions  of  weakness,   and 
when  a  cavity  approaches  a  groove  or  pit  a  good  margin,  histologically, 


HISTOLOUIVAL   RKQ^IREMENTS  IN   ENAMEL    WALL^ 


79 


cannot  he  prepared  witliont  cntting  beyond  it.  V\\f^.  5;i  shows  an 
occlusal  fissure  in  a  bicuspid,  which  illustrates  the  conditions  of  structure 
characteristic  of  these  positions.  The  rods  are  inclined  tcnvard  the 
fissure,  and  between  the  bottom  of  the  fissiu-e  and  the  dentin  are  very 
irregular.  If  a  cavity  wall  were  made  to  approach  this  fissure  from 
the  lingual  side,  so  as  to  come  to  the  dotted  line,  the  wall  would  hav(; 
to  be  inclijied  (\  to  <S  centigrades  (20  degrees  to  2<S  degreivs)  from  the  axial 
plane  toward  the  fissure,  and  then  the  cavosurface  angle  bevelled,  when 
the  conditions  would  be  similar  to  those  in  the  wall  of  an  axial  surface 
cavity,  and  not  as  strong  as  the  location  re(juires.     Not  only  is  this  true, 

Fig.  53 


structure  of  enamel  about  a  fissure:  B,  buccal  side;  L,  lingual  side.     (About  70   X  ) 


but  it  also  leaves  a  vulnerable  point  next  to  the  margin  of  the  filling— 
a  point  of  liability.  Cutting  just  beyond  the  fissure,  the  wall  may  be 
left  in  the  axial  plane  and  have  an  ideally  strong  margin,  and  the  point 
of  liability  is  removed.  To  state  the  conditions  in  general  terms,  a 
strong  margin  is  more  easily  obtained  where  enamel  rods  are  inclined 
toward  the  cavity  than  where  they  are  inclined  away  from  the  cavity. 

The  points  of  cusps  and  the  crests  of  marginal  ridges  are  positions  of 
strength  in  the  perfect  tissue;  but  when  a  cavity  margin  approaches 
them  they  become  points  of  weakness,  because  it  is  impossible  to  sup- 
port properly  the  rods  which  form  the  margin.     Over  the  margmal 


80 


DENTAL  IllSTOLOCY  AND  OPERATIVE  DENTISTRY 


ridges  are  many  short  rods  which  do  not  reach  the  dentin,  and  tliese 
are  usually  nuich  twisted  about  each  other,  so  as  to  form  the  strongest 
possible  keystone  in  the  perfect  structure.  In  preparing  a  margin 
in  such  a  position  it  is  impossible  to  have  the  rods  which  form  the 
margin  reach  the  dentin  with  their  inner  ends,  and  these  short  rods 
are  sure  either  to  break  in  completing  the  operation  or  to  break  out 
later.    The  arrangement  of  enamel  rods  in  such  positions  is  to  be  borne 


Fig.  54 


Bucco-liiiguiil  section  of  upper  bicuspid;  enamel  is  broken  from  cniidine:  A  to  B,  area  of 
weakness  for  enamel  margins.     (.\bout20X) 


in  mind,  especially  when  extending  approximal  cavities  in  inci.sors 
toward  the  lingual  side  and  in  large  pit  cavities  in  incisors.  A  similar 
condition  is  found  over  the  points  of  the  cusps.  P'ig.  54  shows  a  bucco- 
lingual  section  of  an  upper  bicuspid.  It  will  be  noticed  that  the  rods 
forming  the  point  of  the  cusp  are  not  in  the  axial  plane,  and  do  not 
reach  the  tip  of  the  dentin  cusp,  but  reach  the  dentin  a  little  way 
down  on  the  outer  slope.      The  enamel  covering  the  tip  of  the  dentin 


iiisroLoaicAL  reqiihkmknts  in  enamel  walj.s 


81 


contains  many  sliort  rods,  and  tliey  are  very  mnch  twisted  about  each 
other,  so  that  tlie  area  from  A  and  B  to  the  point  of  the  cusj)  is  an  area 
of  Aveakness  for  cayity  niary-ins.      If  the  nuiro-in  reaches  this  area,  the 


Fit!.  55 


Enamel  over  tip  of  dentin  cusp:   D,  dentin  cusp.     (About  80  X) 

cusp  must  be  cut  awav  and   the  enamel  wall  carried  out  in  the  hori^ 
zontal   plane.      Fig.   55   shows   this   area   n:iore  highly  magnified,   and 
illustrates  the  structure.     It  will  be  noticed  that,  in  grinding,  some  of 
the  short  twisted  rods  have  broken  out  of  the  section. 
6 


82 


DENTAL   HISTOLOGY  AND  OPERATIVE  DENTISTRY 


F\(^.  5()  sliows  the  tij)  of  an  incisor  in  lal)iolin<jjual  section,  and  is  of 
interest  in  relation  to  the  formation  of  marii;ins  in  step  cavities  in  in- 
cisors. The  tij)  of  this  tooth  has  been  worn  off  in  nse.  The  illustration 
shows  that  the  threat  inclination  of  the  rods  toward  the  axial  plane  in 
the  occlusal  third  of  the  incisors  is  such  as  to  bring  the  wear  almost  at 
right  angles  to  the  direction  of  the  rods. 

Fig.  56 


Tip  of  ;m  incisor.     (About  50  X) 


DENTIN 

The  structure  of  dentin  is  of  comparatively  little  interest  in  the  pres- 
ent consideration,  as  its  histological  forms  do  not  directly  influence 
the  cutting  of  the  tissue  in  the  excavation  of  cavities.  Its  histological 
forms  have,  however,  much  to  do  with  the  penetration  of  caries  and 
with  other  considerations  which  are  of  importance  to  the  intelligent 
practice  of  operative  dentistry. 


DENTIN 


83 


Dentin  l)olon<i;s  to  the  coniioctivo-tissnc  <!;r()u]>,  and  is  made  up  of 
a  solid  organic  matrix  impregnated  with  about  72  per  cent,  of  inorganic 
salts^  and  pierced  by  minute  canals  or  tubules,  which  radiate  from  a 
central  cavity  which  contains  the  remains  of  the  formative  organ,  or 
pulp.  The  minute  canals,  or  dcniinid  fnhules,  are  occupied  in  life 
by  protoplasmic  processes  from  the  ()dontol)lastic  cells  which  form  the 


Fic.  57 


Dentin  at  dento-enamel  junction,  showing  tubules  cut  longitudinally:  Dt,  dentinal  tubules; 
D,  dentin  matrix.     (About  760  X) 


outer  layer  of  the  pulp.  Dentin  contains  two  kinds  of  organic  matter, 
the  contents  of  the  tubules  and  the  organic  basis  of  the  matrix.  The 
dentin  matrix,  after  the  removal  of  the  calcium  salts  by  acids,  yields 
gelatin  on  boiling  and  resembles  the  matrix  of  bone,  reacting  in  a  similar, 
though  not  identical,  way  with  staining  agents.     The  portion  of  the 


1  Von  Bibra  gives  the  following  analysis  of  dentin: 

Organic  matter 27 .  61 

Fat 0.40 

Calcium  phosphate  and  fluorid 66.72 

Calcium  carbonate 3.36 

Magnesium  phosphate 1 .  08 

Other  salts .,      ,      .      .  0.83 


84 


DENTAL  HISTOLOGY  AND  OPERATIVE  DENTISTRY 


matrix  immediately  .surrounding  the  tul)ules  shows  (h'fferent  chemical 
characteristics  from  the  rest  of  the  matrix,  resembling  elastin,  and 
resisting  the  action  of  strong  acids  and  alkalies  after  the  rest  of  the 
tissue  has  been  destroyed.  This  portion  of  the  matrix  .surrounding  the 
tul)ules  and  lying  next  to  the  fibrils  is  known  as  the  sheaths  of  Neumann. 

The  dentinal  tubules  are  from  1.1  to  2.5  microns  in  diameter,  and 
are  separated  from  each  other  by  a  thickness  of  about  10  microns  of 
dentin  matrix.  This  is  fairly  unif(jrm  throughout  the  dentin.  The 
character  of  the  tubules  is  different  in  the  crow'n  and  root  portions. 

In  the  crown  the  tubules  branch  but  little  through  most  of  their 
course;  but  in  the  outer  part,  close  to  the  enamel,  they  branch  and 
anastomose  with  each  other  (juite  freely.     Fig.  57  shows  a  field  of  dentin 


Fig.  58 


Dentin  showing  tubules  in  cross-section:  Dt,  dentinal  tubules;   D.  dentin  matrix;  .S',  shadow 
of  sheaths  of  Neumann,     (.\bout  11.50  X) 


just  beneath  the  enamel,  as  .seen  with  a  high  power,  and  shows  the 
diameter  of  the  tubules,  their  branching,  and  the  amount  of  matrix 
between  one  tubule  and  the  next.  The  relation  of  one  tubule  to  each 
other  is  shown  also  in  .sections  cut  at  right  angles  to  their  direction 
(Fig.  58).  In  the  crown  portion  the  tubules  pass  from  the  pulp  chamber 
to  the  dento-enamel  junction  in  sweeping  curves,  so  as  to  enter  the  pulp 
chamber  at  right  angles  to  the  surface,  and  end  next  to  the  enamel  at 


right  angles  to  that  surface.    This  produces  S-  or  F-shaped  (  \  or 

curves,  which  are  known  as  the  primary  curves  of  the  tubules.  Through- 
out their  course  the  tubules  are  not  straight,  but  show  a  great  many 
wavy  curves,  known  a^  the  secondary  curves,    "^rhese  appear  as  waves 


DENTIN 


85 


when  seen  in  longitudinal  sections,  but  are  really  the  effect  of  an  open 
spiral  direction,  as  is  seen  by  changing  the  focus  of  the  microscope  in 
studying  sections  cut  at  right  angles  to  the  direction  of  the  tubules. 
The  branches  throughout  their  length  are  few  and  small,  and  are  given 
oif  at  an  acute  angle  to  the  direction  of  the  tubule;  but  just  before  the 
enamel  is  reached  the  tubules  fork  and  branch,  producing  an  appearance 
similar  to  the  delta  of  a  river.  These  branches  are  given  off  from  the 
tubules  for  some  little  distance  back  from  the  enamel,  and  they  anas- 
tomose with  other  tubules  very  freely.  The  branching  of  the  tubules 
in  their  outer  portion  causes  the  spreading  of  caries  just  beneath  the 


Fig.  59 


Crown  of  a  molar,  mesio-distal  section,  showing  penetration  of  caries:  A,  caries  penetrating  dentin; 
B,  line  of  abrasion;  P,  pulp  chamber.     (About  20   X  ) 


enamel,  the  microorganisms  growing  through  the  branches  from  tube 
to  tube,  and  so  spreading  sideways  beneath  the  enamel  plates,  and  then 
penetrating  the  dentin  in  the  direction  of  the  tubules.  Fig.  59  shows 
the  penetration  of  caries  in  the  dentin.  It  will  be  noticed  that  in  decay 
starting  at  the  contact  point  there  has  been  more  spreading  under  the 
enamel  than  in  that  starting  at  the  gingival  line,  but  in  both  positions 
the  penetration  has  followed  the  direction  of  the  tubules. 

In  the  root  portion  the  tubules  pass  out  from  the  pulp  canals  at  right 
angles  to  the  long  axis  of  the  tooth  and  pass  directly  out  to  the  cemen- 
tum,  showing  only  the  secondary  curves.  Throughout  their  course  they 
give  off  a  great  many  fine  branches  passing  through  the  matrix  in  all 


8G  DENTAL  HISTOLOGY  AND  OPERATIVE  DENTISTRY 

Fig.  00 


Dentin  from  the  root,  showing  tubules  cut  longituilinally.    (About  TOO  •   ) 


Fr<i.  m 


Dento-eiiamel  junctiuii.     (About  7(ix  ) 


DENTIN 


87 


directions  from  tul)ule  to  tubule.  These  branches  are  so  numerous  that 
in  sections  which  have  been  mounted  in  such  a  way  as  to  leave  air  in 
them,  or  if  tiie  tubules  have  been  filled  with  coloring  matter,  they  f^ive 
the  impression  of  looking  through  a  hazel  bush;  or  they  may  be  likened 
to  the  fine  rootlets  of  a  plant.  These  fine  branches  are  shown  in  Fig. 
(')(),  and  the  character  of  the  dentin  in  the  root  {)ortion  is  to  be  compared 
with  that  in  the  crown  poi-tion  as  shown  in  Fig.  57.  The  outermost 
layer  of  the  dentin  next  to  the  cementum  contains  many  small  irregular 


Fig.  62 


Interglobular  spaces  in  dentin:  Ig,  first  line  of  interglobular  spaces;  Ig' ,  second  line  of  inter- 
globular spaces.     (About  30  X  ) 


spaces,  which  connect  with  the  dentinal  tubules  and  give  to  the  tissue 
when  seen  with  low  powers  a  granular  appearance.  This  layer  was 
first  described  by  John  Tomes  as  the  granular  layer,  and  has  since 
been  usually  called  the  granular  layer  of  Tomes.  The  spaces  of  the 
granular  layer  are  probably  filled  by  the  enlarged  ends  of  the  den- 
tinal fibrils.  The  same  appearance  is  sometimes  seen  beneath  the  enamel, 
but  is  never  as  well  marked  as  next  to  the  cementum. 

The  dentin  at  the  dento-enamel  junction  seldom  presents  a  smooth 
surface,  but  the  inner  surface  of  the  enamel  plate  shows  rounded  pro- 
jections, between  which  the  dentin  extends.     In  sections  this  gives  to 


88 


DENTAL  IIISTOLOCY  AXD  OPERATIVK  DEXTISTRY 


the  (lento-enaniel  jiiiK'tion  a  scalloped  apj)earaiice,  as  shown  in  V\^^.  01 ; 
and  often  the  decej)tive  aj)j)earanee  of  the  dentinal  tiihnles  penetrating 
for  a  short  distance  between  the  enamel  rods. 


Fin.   63 


Granul:ir  layer  of  Tomes:  L,  lacuna>  of  cementum     Gt.  Rranular  layer  of  Tonics;   l(i.   inter- 
globular spaces.     (About  200    X  ) 


In  many  specimens  made  bv  ^riiuling  dried  teeth  lar<]je  irregular 
spaces  are  very  conspicuous  in  the  dentin.  They  usually  occur  in  lines 
or  zones  at  al)out  uniform  depth  from  the  surface.  These  have  been 
called  the  interglobular  spaces.  They  are  really  not  spaces  at  all,  but 
are  areas  of  imperfect  development  in  which  the  dentin  matrix  has 
not  been  calcified.  The  dentinal  tubules  pass  through  them  without 
interruption.  In  a  dried  specimen  the  organic  matrix  shrinks,  and  the 
resulting  space  becomes  filled  with  the  debris  of  grinding,  so  as  to  give 
the  appearance  of  black  spaces.  Fig.  ()2  shows  two  (|uite  distinct  layers 
of  interglobular  spaces,  the  second  much  more  marked  than  the  first; 
and  in  the  enamel  at  a  position  corresponding  to  the  first  is  .seen  an 
imperfection  of  structure  marked  l\v  the  very  dark  stratification  band. 
This  is  shown  best  in  the  region  of  the  cusp  (Fig.  44)  from  the  same 
section.  Interglobular  spaces  in  the  root  portion  of  the  dentin  are 
shown  in  Fig.  63,  close  to  the  granular  layer  of  Tomes. 


PULP 


89 


The  formation  of  dentin  is  not  complete  at  tlie  tim(>  of  enijition  of 
the  tooth,  hut  continues  for  an  indelinite  period,  thickenin<i-  tlie  hiyer  of 
dentin  at  the  expense  of  the  pulp.  When  the  typical  amount  of  dentin 
has  been  formed  the  growth  ceases,  and  does  not  begin  again  unless 
excited  by  some  irritation  to  the  pulp  or  the  })nlp  of  soiue  other  tooth 
of  the  same  side,  which  leads  to  the  formation  of  secondary  dentin. 
Secondary  dentin  is  never  as  perfect  in  structure  as  primary  dentin; 
the  tubules  are  smaller,  fewer,  and  much  more  irregular.  Often  in 
ground  sections  several  periods  of  formation  can  be  fletermined  by 
differences  of  structiu'e,  each  deposit  becoming  successively  more  and 
more  imperfect  in  structure.     This  is  shown  in  Fig.  ()4. 


Fig.   C4 


Secondary  dentin:    A.  margin  of  primary  deatin,  showing  a  few  ,.f  the  tubules  continuing 
into  the  secondary  dentin;    P,  pulp  chamber.       (About  SO   X) 


PULP 

The  dental  pulp  is  the  soft  tissue  occupying  the  central  cavity  of  the 
dentin.  It  is  made  up  of  embryonal  connective  tissue  and  contanis  a 
large  number  of  bloodvessels  and  nerves.  Like  all  connective  tissues, 
the  intercellular  substance  is  large  in  amount  and  the  cells  are  widely 
scattered  in  this  soft,  jelly-like  tissue,  which  contains  but  few  fibers. 
We  recognize  four  kinds  of  cells  in  the  pulp— the  odontoblasts,  formmg 


90  DENTAL   HISTOLOGY  AND  OPERATIVE  DENTISTRY 

the  outer  surface  of  the  pulp  next  to  the  deiitiii;  and  round,  spindle- 
shaped,   and   stellate  connective-tissue  c-ells. 

Arrangement  of  Cells. — The  odoidulAmts  are  tall  columnar  cells,  some- 
times club-shaped,  and  in  older  tissues,  which  have  ceased  to  be  func- 
tional, sometimes  becoming  almost  spherical.  They  form  a  continuous 
layer  over  the  entire  .surface  of  the  pulp,  being  everywhere  in  contact 
with  the  dentin.  The  layer  has  been  called  the  ntrmhniiKi  chori.s,  or  the 
"membrane  of  the  ivory." 

The  nuclei  of  the  odontoblasts  are  large  and  oval,  containing  a  large 
amount  of  chromatin,  and  aic  very  diliVrciit  from  the  nuclei  of  ordinary 
connective-tissue  cells. 

Fig.  65 


F 
N 


f  ^^ 


p 


J, 


w 


Odontoblasts.  The  section  cuts  obliquely  through  the  odontobhists:  /•",  fibrils;  A',  nuclei  of 
odontoblasts;  .V',  nuclei  of  connective-tissue  cells;  If,  layer  of  Weil,  not  well  shown.      (.■Xbout  80  X  ) 

Three  kinds  of  processes  have  been  described  in  connection  \\ith  the 
odontoblasts : 

1.  The  dentinal  fibril  proces.ses,  or  fibers  of  Tomes.  These  are  long, 
slender  protoplasmic  proces.ses  projecting  from  the  dentin  end  of  the 
cell  into  a  dentinal  tubule,  and  running  through  the  tubule  to  the  outer 
.surface  of  the  dentin.  U.sually  there  is  but  one  fibril  extending  from 
each  odontoblast,  but  sometimes  two  can  be  seen,  extending  into  two 
tubules.  These  fibrils  can  be  demonstrated  in  decalcified  sections  or 
by  removing  the  pulp  from  a  recently  extracted  tooth  by  cracking  the 
tooth  and  carefully  lifting  the  pulp  out  of  the  pulp  chamber,  and  then 
either  teasing  or  sectioning.  Fig.  65  shows  the  fibrils  projecting  from 
the  surface;  but  in  this  .section  the  cut  was  not  in  the  direction  of  the 
long  axis  of  the  odontoblasts,   but  obli(|uely  through  them.     Fig.  GG 


PULP 


91 


(from  a  pliotoo-raph  by  Rose)  shows  the  form  of  the  odontohhists  in  a 
young  tooth  in  which  formation  of  dentin  is  actively  progressing,  with 
the  fibrils  in  the  dentinal  tubules. 

2.  Lateral  processes  projecting  from  the  sides  of  the  cells  and  uniting 
one  with  another  in  the  formation  of  the  layer. 

3.  Pulpal  processes,  projecting  from  the  pulpal  ends  of  the  odonto- 
blasts into  the  layer  of  Weil. 

The  odontoblasts,  as  the  name  indicates,  are  the  dentin-forming 
cells.  They  superintend  the  formation  and  calcification  of  the  dentin 
matrix,  the  fibril  being  left  behind  surrounded  by  the  formed  tissue. 
Whether  the  fibrils  have  any  share  in  the  formation  and  calcification  of 
the  dentin  matrix  has  been  a  matter  of  controversy. 


Fig.  66 


-Dp 


Odontoblasts  and  forming  dentin:  E,  forniins:  enamel;  D,  forming  dentin;  O,  odontoblasts; 
Dp,  body  of  dental  papilla.     (From  photomicrograph  by  Rose.) 


The  relation  of  the  fibrils  to  the  transmission  of  sensation  is  also  a 
matter  of  dispute;  but  at  present  the  weight  of  evidence  is  that  they 
in  some  way  transmit  impressions  to  the  sensory  nerves  of  the  pulp. 

Just  beneath  the  layer  of  odontoblasts  is  a  zone  which  contains  very 
few  connective-tissue  cells.  In  thin  sections,  especially  in  the  body  of 
the  pulp,  this  appears  as  a  clear  layer  about  half  as  thick  as  the  layer 
of  odontoblasts.  It  is  known  as  the  layer  of  Weil.  Just  beneath  the 
layer  of  Weil  the  connective-tissue  cells  are  especially  numerous  and 
form  a  more  or  less  distinct  layer  of  closely  placed  cells.  In  the  rest  of 
the  body  of  the  pulp  the  cells  are  about  uniformly  distributed  throughout 


92 


DENTAL  HISTOLOGY  AND  OI'KRATIVE   DENTISTRY 


the  intercellulur  suhstaiur.      'I'licsc  coimcctivo-tissiie  colls  are  of   the 
characteristic  forms,  rather  small,  contaiiiiiin;  a  small  but  (leej>-staining 


Fi.;.  (17 


Diagram  of  \\w  liloodvessels  of  the  pulp.     (Stowell.) 


y^^ 


y*    • 


—5/ 


! 


•  ' 


iA 


A  pulp  bloodvessel,  showing  the  thin  wall:  C,  blood  corpuscles  in  the  vessel;  Bl,  bloodvessel 
wall  showing  nuclei  of  endothelial  cells;  .V,  nuclei  of  connective-tissue  cells  in  the  body  of  the  pulp; 
/,  intercellular  substance,  showing  a  few  fibers,     (.\bout  200 X  ) 


nucleus,  the  protoplasm  stretching  out  into  slender  projections  in  two 
directions  to  form  the  spindle  cells,  or  in  more  than  two  ilirections  to 


PULi'  93 

form  the  stellate  cells.  Th(>  stellate  forms  are  more  eotnmoii  in  the 
body  of  the  j)ulj),  tiie  spindle  form  in  the  canal  portions.  The  round 
cells  are  comparatively  few  in  number,  and  are  pi-obably  young  cells 
which  have  not  yet  accjuired  the  adult  form. 

The  Bloodvessels  of  the  Pulp. — 'J'he  blood  supply  of  the  pulp  is  extremely 
rich,  several  arterial  vessels  entering  in  the  region  of  the  apex  of  the  root, 
often  through  several  foramina.  These  large  vessels  extend  occ-lusally 
through  the  central  portion  of  the  tissue,  giving  oif  many  branches  which 
break  up  into  a  very  close  and  fine  capillary  plexus  (Fig.  67).  From  the 
capillaries  the  blood  is  collected  into  the  veins,  which  pass  apically  through 
the  central  portion  of  the  tissue.  A  very  striking  peculiarity  of  the  blood- 
vessels of  the  pulp  is  the  thinness  of  their  walls.  Even  the  large  arteries 
show  scarcely  any  condensation  of  fibrous  tissue  around  them  to  form 
the  usual  adventitious  layer,  and  usually  contain  but  a  single  involuntary 
muscle  fiber  representing  the  media,  while  the  walls  of  even  the  large 
veins  are  made  up  of  only  the  single  layer  of  endothelial  cells  forming 
the  intima,  and  are  in  structure  like  large  capillaries  (Fig.  68).  This 
peculiarity  of  the  bloodvessel  walls  is  of  great  importance,  as  it  renders 
the  tissue  especially  liable  to  such  pathological  conditions  as  hyperemia 
and  inflammation. 

The  Nerves  of  the  Pulp. — Several  comparatively  large  bundles  of  medul- 
lated  nerve  fibers,  containing  from  six  or  eight  to  fifteen  or  twenty 
fibers,  enter  the  pulp  in  company  with  the  bloodvessels  and  pass  occlu- 
sally  through  the  central  portion  of  the  tissue.  These  bundles  branch 
and  anastomose  with  each  other  very  freely.  Most  of  the  fibers  lose  their 
medullary  sheath  before  reaching  the  layer  of  Weil,  in  which  position 
they  form  a  plexus  of  non-medullated  fibers ;  from  these  fibers  free  endings 
are  given  off,  which  penetrate  between  the  odontoblasts.  In  some  cases 
these  have  been  followed  over  on  to  the  dentinal  ends  of  the  odontoblasts, 
but  in  no  instance  have  they  been  followed  into  the  dentinal  tubules. 

The  Functions  of  the  Pulp. — The  pulp  performs  two  functions,  a  vital 
and  a  sensory. 

The  vital  function  is  the  formation  of  dentin,  and  is  performed  by 
the  layer  of  odontoblasts.  This  is  the  principal  function  of  the  pulp, 
and  it  is  first  manifested  in  the  development  of  the  tooth  before  the 
dentinal  papilla  is  converted  into  the  dental  pulp  by  being  enclosed 
in  the  formed  dentin.  After  the  tooth  is  fully  formed  the  vital  func- 
tion is  not  manifested  unless  the  pulp  is  stimulated  by  some  excitation 
affecting  trophic  centres  and  which  causes  the  formation  of  secondary 
dentin.  There  are  some  exceptions  where  the  formation  is  entirely 
local. 

The  Sensory  Function. — In  regard  to  sensation,  the  pulp  resembles 
an  internal  organ.  It  has  no  sense  of  touch  or  localization,  and  responds 
to  stimuli  only  by  sensations  of  pain.  The  pain  is  usually  localized 
correctly  with  reference  to  the  median  line,  but,  aside  from  that,  is 


94 


DKXTAL   IIIST()IJ)(;Y   AM)  Ol'KR Ml  V F.    D/JXTISTRY 


locali/ed  only  us  it  is  referred  to  some  known  lesion.  If  several  j)nlps 
on  the  same  side  of  the  mouth  and  in  teeth  of  both  the  upper  and  lower 
arches  were  exposed  so  that  they  could  be  irritated  without  impressions 
reaching  the  peridental  membrane,  and  the  patient  were  blindfolded, 
it  would  be  impossible  for  him  to  tell  which  of  the  pulps  was  touched. 
The  pain  originating  from  a  tooth  jndp  may  be  referred  to  the  wrong 
tooth  or  to  almost  any  point  on  tiie  same  side  supplied  by  the  fifth 
cranial  nerve. 

The  pulp  is  especially  sensitive  to  changes  of  temperature,  but  is 
incapable  of  differentiating  between  heat  and  cold;  this  fact  is  often 
made  use  of  in  differential  diagnoses.  The  pulp  is  also  very  sensitive 
to  traumatic  and  chemical  irritations,  even  when  these  are  conveyed 
to  it  through  the  agency  of  the  dentinal  fibrils.  I  )r.  Huber  has  suggested^ 
that  this  transmission  may  be  accomplished  by  the  traumatic  or  chemical 
action  upon  the  fibrils  setting  up  metabolic  changes  in  the  odontoblastic 
cells,  which  act  as  stimuli  to  the  sensory  nerves  ending  between  the 
cells  of  that  layer. 


CEMENTUM 

The  cementum  covers  the  surface  of  the  dentin  apically  from  the 
border  of  the  enamel,  lapping  sliglitly  over  the  enamel  at  the  gingival 
margin  (Fig.  69).     It  forms  a  layer,  thickest  in  the  apical  region  and 

Fir..  69 


Gingival  border  of  enamel,  showing  the  cementum  overlapping  it:  E,  enamel;  C,  cementum; 

D,  dentin.     (About  40  X) 


>  Dental  Cosmos,  October,  1698. 


CEMENT  UM 


95 


between  the  roots  of  biciisj)Ld.s  and  molars,  and  heeoniino'  thinner  as  the 
gingival  line  is  approached.  The  eenientuni  resembles  subperiosteal 
bone  in  structure,  but  differs  from  it  in  the  character  and  arrangement 
of  the  lacuna^  and  in  the  absence  of  Haversian  systems;  the  layers,  or 
lamella%  of  the  cementum  also  are  less  uniform  in  character  than  those 
of  bone. 

The  function  of  the  cementum  is  to  furnish  attachment  for  the 
fibers  of  the  peridental  meml)rane  which  holds  the  tooth  in  its  position. 
The  surrounding  tissues  are  never  in  physiological  connection  with  the 
outer  surface  of  the  dentin,   except  to  form  cementum  over  it  or  to 


Fic.  70 


Cementum  near  the  apex  of  the  root:  Gt,  granular  layer  of  Tomes;  L.  lacunae,  b,  point  at  which 
fibers  were  cut  off  and  reattached.     (About  54  X ) 


remove  its  substance  by  absorption;  and  when  absorption  of  the  dentin 
has  occurred  on  the  surface  of  a  root  it  is  never  repaired  except  by  the 
formation  of  cementum  to  fill  up  the  cavity  and  reattach  the  membrane. 
The  cementum  is  intermittently  formed  during  the  functioning  of 
the  tooth,  being  added  layer  after  layer  over  the  entire  surface  of  the 
root,  the  difference  in  thickness  of  the  tissue  in  the  gingival  and  apical 
portions  being  chiefly,  though  not  entirely,  due  to  the  difference  in 
thickness  of  each  layer  in  the  two  positions  (Figs.  69,  70).  The  cemen- 
tum on  the  roots  of  newly  erupted  teeth  is  thin,  and  on  the  roots  of 
teeth  of  old  persons  is  thick.     This  continued  formation  of  cementum 


96  DENTAL  niSTOLOUY  AX U  Ul'EliATl\  E   UEXTISTRY 

Fu..  71 


Thic-k  liimella'  of  cementum  witli  inany  laciin*,  tiliniLr  an  alisdrption  iii  ikiuhi;  i..  iacunse;  //, 
Howship's  lacunse  filled  ;  D,  dentin.    (About  250  >  .) 


Fig.  72 


Two  Melds  ot  cenientuui  sii(i\vin'4  in'iu'tratin!,'  lihers  :  (jf.  tiianiiiar  layer  ot    1  omcs ;  C,  ceineliluni 
not  showing  fibers  ;  F,  pciH'lT«M»g  fibers,    (.\bout  54  •;.) 


PERIDENTAL   MEMBRANE  97 

is  duo  to  the  necessity  for  cliange  and  reattaclinient  of  the  fibers  of  tlie 
membrane. 

In  the  ging'ival  j)()rtioiis,  where  the  cementuin  is  thin,  the  tissue  is 
clear  and  apparently  structureless,  and  usually  contains  no  lacunar; 
while  in  the  apical  half  and  between  the  roots  the  lacunae  are  numerous. 
In  general,  wherever  the  lamelhe  are  thin,  the  lacuna"  are  absent;  but 
where  the  lanieihe  are  thick  they  are  found.  The  canaliculi  which 
radiate  from  the  lacunae  are  not  as  regular  as  in  the  case  of  the  lacunae 
of  bone.  Sometimes  they  are  numerous,  sometimes  few;  they  may 
extend  from  a  lacuna  in  all  directions,  or  they  may  be  confined  to  one 
side,  usually  the  side  toward  the  surface  of  thecementum  (Fig.  71). 

The  cementum  is  penetrated  through  all  its  layers  by  fibers  of  the 
peridental  membrane  which  have  been  embedded  in  the  matrix  of  the 
tissue  and  calcified  along  with  it.  The  first  layer — that  is,  the  one  next 
to  the  dentin — is  usually  structureless  and  shows  no  fibers  in  it,  at 
least  in  its  inner  half.  In  ground  sections  the  embedded  fibers  often 
appear  in  a  number  of  layers,  while  they  are  not  apparent  in  the  rest 
of  the  thickness.  This  is  because  just  before  and  just  after  the  forma- 
tion of  the  layers  in  which  they  appear  the  fibers  were  cut  oft'  and 
reattached,  changing  their  direction,  so  that  in  the  other  layers  the 
fibers  are  cut  transversely  or  oblicjuely.  This  is  illustrated  in  Fig.  72. 
These  embedded  fibers  are  very  numerous  in  some  places.  If  properly 
stained,  the  tissue  seems  almost  a  solid  mass  of  fibers.  In  ground 
sections  these  have  sometimes  been  mistaken  for  minute  canals  from  the 
fact  that  they  are  not  always  as  fully  calcified  as  the  cementum  matrix, 
and  shrinkage  causes  the  appearance  of  little  open  canals. 

Hypertrophies  of  the  cementum  (formerly  often  called  exostoses,  or 
excementoses)  are  very  common.  The  increased  thickness  may  be  of 
one  lamella  or  of  several  lamellae  in  the  region  of  the  hypertrophy,  or 
all  of  the  layers  from  first  to  last  may  take  part  in  it.  Small  local  thick- 
enings of  a  single  lamella  are  seen  in  connection  with  the  peridental 
membrane  wherever  a  specially  strong  bundle  of  fibers  is  to  be  attached 
to  the  root  to  support  the  tooth  against  some  special  strain. 

PERIDENTAL  MEMBRANE 

The  peridental  membrane  may  be  defined  as  the  tissue  which  fills 
the  space  between  the  root  of  the  tooth  and  the  bony  wall  of  its  alveolus, 
surrounds  the  root  occlusally  from  the  border  of  the  alveolus,  and 
supports  the  gingiva.  It  has  been  referred  to  under  many  names, 
as  pericementum,  dental  periosteum,  alveolodental  periosteum,  etc. 
While  this  tissue  performs  the  functions  of  a  periosteum  for  the  bone 
of  the  alveolus,  it  differs  in  structure  from  the  periosteum  in  any  posi- 
tion, so  that  any  name  including  the  word  periosteum  or  implying  a 
double  membrane  should  be  avoided. 
7 


98  DENTAL   IIISTOUKIY  AND  OrERATIVE   DENTISTRY 

The  peridental  rnenil)rane  belongs  to  the  class  of  fihrous  membranes, 
and  is  made  uj)  of  the  followiiif;  structural  elements: 


Fic.   73 


Diagram  of  the  fibers  of  the  peridental  membrane:  G.  KinRival  portion;  Al,  alveolar  portion; 
Ap,  apical  portion.     (From  a  jjliotograph  of  a  section  from  incisor  of  sheep.) 


1.  Fibers.  2.  Fibroblasts.  3.  Cementoblasts.  4.  Osteoblasts.  5, 
Osteoclasts.  0.  Epithelial  structures  which  have  been  called  the  glands 
of  the  peridental  membrane.     7.  Bloodvessels.     .S.  Nerves. 

The   peridental    membrane    performs    three    functions — a    'physical 


PERI  DKNTA  L  MEM  Bit  A  NE 


99 


function,   maintaining  the  tooth  in  rehition  to  the  adjacent  hard  and 
soft  tissues;  a  vital  function,   tiie  formation  of  bone  on  the  alveolar 


Fir;.  74 


Longitudinal  section  of  peridental  membrane  from  young  sheep,  showing  fibers  penetrating 
cementum:  D,  dentin;  C,  cenientum,  showing  embedded  fibers;  F,  fibers  running  to  outer  hiyer 
of  periosteum  covering  the  alveolar  process;  F',  fibers  running  to  the  bone  at  the  border  of  the 
process;  5,  bone.     (About  80  X) 


wail  and  of  cementum  on  the  surface  of  the  root;  and  a  sensor]/  function, 
the  sense  of  touch  for  the  tooth  being  exclusively  in  this  membrane. 


100         DENTAL   IIISTOUHIY  AS  I)  ()I'KRATI\  E    DESTISTRY 

The  fibrous  tissue  of  the  membrane  is  of  the  white  variety,  and  may 
be  divided  into  two  chisses,  the  j)riii(ij)al  fibers  and  the  indifferent  or 
interfibrous  tissue.  The  principal  fibers  may  l)e  (K'fined  as  those  which 
spring  from  the  cementum  and  are  attached  at  their  other  end  to  the 
bone  of  the  alveolar  wall,  to  the  outer  layer  of  the  periosteum  covering 
the  surface  of  the  alveolar  process,  to  the  cementum  of  the  approximating 
tooth,  or  become  blended  with  the  fibrous  mat  of  the  gum  supporting 
the  epithelium.  They  were  so  called  by  Dr.  Black,  not  only  because 
they  form  the  principal  bulk  of  the  tissue,  but  they  also  perform  tne 
principal  function  of  the  membrane,  the  support  of  the  tooth  and  sur- 


Fi<:.   75 


^      ^ 


\ 

«v>-  '   -'■  »v- 

..'•>^"^ 

' 

M. ' ' 

/•-•  •' 

4 

■•i.- 

/ 

T''-  J  ■ 

■f-f 

'',-^' 

&  ■ 

/...■^^'., 


0? 


Longitudinal  section  of  the  peridental  membrane  in  the  gingival  portion:  £),  dentin;  A'^,  Nasmyth's 
membrane;  (',  cementum ;  F,  fibers  supporting  the  gingi\  us;  f,  fibers  attached  to  the  outer  layer  of 
the  periosteum  o\er  the  alveolar  process;  F-,  fibers  attached  to  the  bone  at  the  rim  of  the  alveolus; 
B,  bone.     (About  30  X  ) 


rounding  tissues.  The  interfibrous  tissue,  also  of  the  white  variety,  but 
made  up  of  smaller  and  more  delicate  fibers,  is  found  filling  spaces 
between  the  principal  fibers  and  surrounding  and  accompanying  the 
bloodvessels  and  nerves. 

For  convenience  of  description  and  study,  the  peridental  membrane 
is  divided  into  three  portions:  the  gingival,  that  portion  which  surrounds 
the  root  occlusally  from  the  border  of  the  alveolar  process;  the  alveolar, 
the  portion  from  the  border  of  the  process  to  the  apex  of  the  root;  and 
the  apical  portion,  surrounding  the  apex  of  the  root  and  filling  the 
apical  region  (Fig.  73). 


PERIDENTAL   MEMBRANE 


101 


The  principal  fihors  sj)riiio-  from  the  (•ciiumiIiiim,  the  (•(Miiciitohlast.s 
building  u{)  tlic  matrix  around  (hem  and  tlicn  calcifvino;  hoth  matrix 
and  fibers,  in  this  way  iinplantino-  their  ends  inio  the  surface  of  the 
root.  In  Fig-.  74  the  fibers  are  seen  passing  through  the  last-formed 
layer  of  cenientuni.  In  most  positions  the  fibers  as  they  spring  from 
the  cementum  appear  as  well-marked  bundles  of  fine  fibers.  A  short 
distance  from  tiie  surface  of  the  root  they  break  up  into  smaller  bundles, 
which  interlace  and  are  reunited  into  laro'er  bundles,  to  be  attached 
at  their  other  extremity  to  the  bone,  cementum,  or  fibrous  tissue. 


Fig.  76 


Transverse  section  of  the  peridental  nienil>rane  in  the  t;inKi\  ai  portion  (from  slieep):  E,  epithe- 
lium: F.  fibrous  tissue  of  gum;  B,  point  where  peridental  membrane  fibers  are  lost  in  fibrous  mat 
of  the  gum;  P,  pulp;  F' ,  fibers  extending  from  tooth  to  tooth.     (About  30  X  ) 


To  arrive  at  an  understanding  of  the  arrangement  of  the  fibers  of 
the  peridental  membrane,  they  must  be  studied  in  both  longitudinal  and 
transverse  sections.  In  longitudinal  sections  of  the  membrane,  in  the 
gingival  portion  (Fig.  75),  the  fibers  springing  from  the  cementum  at 
the  gingival  line  pass  out  for  a  short  distance  at  right  angles  to  the 
long  axis  of  the  tooth  and  then  bend  sharply  to  the  occlusal,^  passing 


1  In  describing  the  direction  and  inclination  of  peridental  membrane  fibers  they  are  always 
traced  from  the  cementum  to  the  bone,  the  angle  with  the  horizontal  plane  being  formed  at  the 
surface  of  the  cementum. 


102 


DENTAL  HISTOLOGY  AND  Ol'EUATIVE   DENTISTRY 


into  the  gingiva  to  .siij)j)()rt  it  and  hold  it  closely  against  the  neck  of 
the  tooth.  These  fihers  are  most  numerous  on  the  lingual  side,  where 
food  is  brought  against  the  gingiva  with  force  in  mastication  and  tends 
to  crush  it  down.  In  the  middle  of  (he  gingival  portion  the  fibers  pass 
out  at  right  angles  to  the  axis  and  are  blended  with  the  fibrous  mat  of 
the  gum  on  the  labial  and  lingual  sides,  or  arc  attached  to  the  cementum 
of  the  adjoining  teeth  on  the  approximal  sides.  A  little  farther  from  the 
gingival  line  the  fibers  are  inclined  slightly  apically,  ])assing  over  the 
border  of  the  process  to  be  attached  to  the  outer  layer  of  the  ])eriosteum. 
These  fibers  are  especially  large  and  strong.  Just  at  the  rim  of  the 
alveolus  the  fibers  are  inclined  slightly  aj)i(ally  and  aic  inserted  into 
the  bone,  forming  the  edge  of  the  process. 


Fig.  77 


Fibers  at  the  border  of  the  alveol.ir  process  (from  sheep):  />,  dentin;  C,  eementuin;  F,  fibers  extend- 
ing from  cementum  to  bone;  Bl,  bloodvessel;  h,  bone.     (About  81)  X) 


In  transverse  sections  of  the  membrane  in  the  gingival  portion  (Fig. 
70)  the  fibers  spring  from  the  cementum  in  large  bundles;  at  the  centre 
of  the  labial  surface  they  extend  directly  outward,  breaking  up  into 
smaller  bundles,  passing  around  bloodvessels  and  bundles  of  hl)ers,  and 
blending  wiUi  the  fibrous  tissue  sup|)orting  the  epithelium.  Passing 
mesiaily  and  distally  toward  the  corners  of  the  root,  the  fibers  swing 
around  laterally  and  pass  to  the  cementum  of  the  next  tooth.  On  the 
approximal  sides  the  fibers  suddenly  divide  into  smaller  bundles,  which 
wind  in  and  out  around  bloodvessels,  and  bundles  of  fibers  which  pa.ss 
into  the  gingiva  and  are  reunited  into  large  bundles  to  be  inserted  into 
the  cementum  of  the  next  tooth.  On  the  lingual  side  the  arrangement 
is  like  that  of  the  labial,  except  Uiat  the  distance  to  which  the  fibers  of 


PERIDENTAL   MEMBRANE 


103 


Fi(!.  78 


Om 


Transverse  section  of  the  peridental  membrane  in  the  occlusal  third  of  the  alveolar  portion 
(from  sheep):  J/,  muscle  fibers;  Pec,  periosteum :  .4/,  bone  of  the  alveolar  process;  Pti,  peri- 
dental membrane  fibers  ;  P,  pulp  ;  D,  dentin  ;  Cm,  cementum. 


104         DEXTAL   IlISTOLOCY   AM)  OI'Kh'ATl  \  K   DKXTISTh'Y 

the  mcmhraiic  can  he  followed  hct'orc  (licv  arc  lost  in  the  lil)i-()iis  mat  of 
the  ^uiii  is  usually  ^M-ea(er  than  on  t\\r  lal)ial. 

In  the  occlusal  third  of  the  alveohir  j)ortioii  of  the  nienihrane  the 
fibers  pass,  at  riirht  anolcs  to  the  axis  of  the  tooth,  directly  from  the 
cementuin  to  the  hone.  In  this  jjosition  the  fibers  are  hir(,^e  and  do  not 
break  up  into  smaller  bundles,  but  the  original  fibers  can  be  followed 
uninterruptedly  from  the  eementum  to  the  bone  (Figs.  74  and  77). 
In  the  middle  third  the  fibers  are  inclined  occlusally,  and  this  inclina- 
tion increases  as  the  a])ical  third  is  ap])roaclied.  In  the  apical  third 
the  inclination  is  i«;reatest,  and  the  lil)ers  as  they  arise  from  the  eemen- 
tum are  very  large  and  break  up  into  fan-shaj)ed  fasciculi  as  they  pass 
across  to  the  bone.  Tn  the  apical  portion  the  fibers  radiate  from  the 
apex  in  all  directions  across  the  apical  region  and  sj>read  out  in  fan- 
shaped  bundles  like  those  in  the  apical  third  of  the  alveolar  portion. 

In  a  transverse  section  near  the  border  of  the  alveolus  (Fig.  7S),  at 
the  centre  of  the  labial  surface  of  the  root,  the  fibers  are  seen  to  extend 
directly  out  from  the  surface  of  the  root  to  tlie  bone  of  the  process, 
excepting  where  they  are  diverted  to  pass  around  bloodvessels.  Passing 
around  distally  at  the  corner  of  the  root,  the  fibers  swing  laterally  so  as 
to  be  almost  at  a  tangent  to  the  surface  of  the  root,  and  are  inserted 
much  farther  to  the  distal  on  the  wall  of  the  alveolus.  A  similar  arrange- 
ment is  noticed  at  the  other  corners  of  the  root,  though  these  tangential 
fibers  are  usually  more  marked  at  the  distal  than  at  the  mesial  corners. 

wStudying  the  arrangements  of  the  fibers  with  reference  to  the  physical 
function  of  the  membrane,  it  is  seen  to  be  the  best  that  could  be  devised 
to  support  the  teeth  against  the  force  of  mastication  and  to  support 
the  tissues  about  them.  In  the  gingival  portion  the  fibers  passing 
from  tooth  to  tooth  form  the  foundation  for  the  gingivae  between  the 
teeth  filling  the  interproximal  spaces;  so  that  if  these  fibers  are  cut 
off  from  the  eementum,  by  extending  a  crown  band  too  far,  or  by  the 
encroachment  of  calculary  deposits  beginning  in  the  gingival  space, 
the  gingiva  drops  down  and  no  longer  fills  the  interproximal  space.  In 
the  alveolar  portion  the  fibers  at  the  border  of  the  process  and  those 
at  the  apex  of  the  root  together  support  the  tooth  against  lateral  strain, 
while  those  in  the  rest  of  the  alveolar  portion  are  so  arranged  as  to 
swnng  the  tooth  in  its  socket  and  suppt)rt  it  against  the  force  of  occlu- 
sion (Fig.  73).  As  seeii  from  the  transverse  section,  the  fibers  of  the 
occlusal  third  of  the  alveolar  portion  are  so  arranged  as  to  support 
the  tooth  against  forces  tending  to  rotate  it  in  its  socket. 

Cellular  Elements  of  the  Membrane. — The  Jihroblasts  are  spindle-shaped 
or  stellate  connective-tissue  cells  which  are  found  between  the  fibers 
as  they  are  arranged  in  bundles.  In  sections  stained  with  hematoxylin 
they  take  the  stain  deeply,  and  the  fibers,  unstained,  are  differentiated 
by  the  cells  lying  in  rows  between  them.  The  number  of  fibroblasts  in 
the  membrane  decreases  with  age.    They  are  large  and  numerous  in  the 


PKRIDESTM.    MEMIiliA SK 


10- 


inenil)ranc  of  a  newly  (Mii|)ti-(1  tootli.  and  (■()iiii)arati\('y  small  and  few 
in  the  membrane  around  an  old  tooth.  This  is  eharaeteristic  of  fibro- 
blasts in  other  positions.  The  Hbroblasts  are  shown  as  they  appear 
in  a   hematoxylin-stained  section  witii   low  powers  in   Fif^.   79,   which 


Fig.  79 


Fibers  and  fibrobhists  from  trans\  erse  ^ci  Uua  uf  membrane:  F,  fibers  cut  transversely:  F\  fibers 
cut  longitudinally,  showing  fibroblasts.     (About  80  X  ) 

gives  part  of  the  membrane  in  the  gingival  portion  between  two  teeth. 
The  cells  are  seen  as  spindle-shaped  dots  which  mark  out  the  fibers; 
at  F  they  are  seen  in  a  position  where  the  fibers  are  cut  transversely. 
With  higher  powers  these  cells  appear  as  in  Figs.  81  and  90. 


Fig.  so 


:^Y^  -C 


Cementobkists.     (Drawing  by  Dr.  Black.) 

The  cementoblasts  are  the  cells  which  form  the  cementum,  and  are 
found  everywhere  covering  the  surface  of  the  root  between  the  fibers 
which  are  embedded  in  the  tissue.  ^Miile  these  cells  perform  the  same 
function  for  the  cementum  as  the  osteoblasts  do  for  bone,  they  are  in 
form  very  different  from  the  osteoblasts.  The  cementoblasts  are  always 
flattened  cells,  sometimes  almost  scale-like,  and  when  seen  from  above 


106         DENTAL   HISTOLOCY  AND  OPERATIVE  DENTISTRY 

are  very  irrefrular  in  oiitliiic.  Tliis  irrci^nilarity  of  outline  is  caused  by 
the  cells  fittiii",^  aroiind  the  attached  fibers  of  the  membrane  so  as  to 
cover  the  entire  surface  of  the  cenientuni  between  the  fibers.  Fig.  80, 
from  a  drawing  by  Dr.  Black/  shows  several  cementoblasts  as  seen 
when  isolated  bv  teasing.  The  cementoblasts  have  a  central  mass  of 
protoplasm  containing  an  oval  nucleus,  and  short  irregular  proces.ses 
which  fit  around  the  fibers  as  these  spring  from  the  surface  of  the  cemen- 
tum.     Fig.   SI    shows   diem   in   section   ])erpendicularly   to   die  surface 


Transverse  section,  showing  the  cellular  elements:  Fb,  fibroblasts;   Ec,  epithelial  structures; 
Cb,  ceinentobla-sts;  Cm,  cenientum;  D,  dentin.     (About  900    X) 

of  the  root,  where  they  are  crowded  between  the  fibers.  The  cemento- 
blasts often  have  processes  projecting  into  the  cementum  like  those 
from  the  osteoblast,  but  processes  projecting  into  the  membrane  have 
never  been  demonstrated. 

In  the  formation  of  the  cementum  occasionally  a  cementoblast  be- 
comes enclosed  in  the  formed  tissue  filling  one  of  the  lacuna',  in  which 
position  it  becomes  a  cement  corpuscle. 


>  Periosteum  and  Peridental  Mpnil>rane. 


PERIDENTAL  MEMBRANE 


107 


Fig.  82 


PclB 


EB 


^Per 


Border  of  growing  process :  Cm,  cementum  :  Prf,  peridental  membrane  :  Prf.B,  solid  subperidental 
and  subperiosteal  bone  with  imbedded  fibers;  Ms,  medullary  space  formed  by  absorption  of 
the  solid  bone;   -ff.-B,  Haversian-system  bone  without  fibers;  Pec,  periosteum.    (About  50 X.) 


108 


DEXTAL   lIISTOLOdY  AS  I)  Ol'ERATIVR   DKSTISTUY 


'i'lic  ().sfc(ihla.s/.s  ot"  the  iii<'iiil)r;iiic  cover  tlic  siirt'acc  of  tlic  l)oiic,  t'oniung 
the  wall  ot"  the  alveolus,  lyiiiu-  iK'twccn  tlic  fiUcrs  which  arc  hiiilt  into 
the  bone.  In  form  and  fiiiiction  they  are  like  the  osteoblasts  in  attached 
portions  of  the  periosteum.  They  form  bone  around  the  ends  of  the 
peridental-memV)rane  fil)ers,  buildirif;  them  into  the  substance  of  the 
bone.     The  bone  thus  formed  over  the  wall  of  the  alveolus  is  like  the 


Fi...  s:; 


r^i  M 


o/>'-^ 


1><I  B 


Penetrating  fibers  in  bone:  PdM ,  peridental  membrane;  O/)',  osteobla.st.s  of  peridental  membrane; 
Ob-,  osteoblasts  of  medullary  space;  PdB,  solid  subperidental  and  subperiosteal  t)one  with  embedded 
fibers;  Ms.  medullary  space  formed  by  absorption  of  the  solid  subperidental  bone  with  embedded 
fibers;  HB,  Haversian-system  bone  without  fibers  built  around  the  medullary  space.  (About 
200   X) 


solid  subperiosteal  bone,  and  is  penetrated  throu(j;hout  its  thickness 
by  the  embedded  fibers;  but,  as  with  the  subperiosteal  bone,  it  is  con- 
stantly being  penetrated  by  perforating  canals,  the  solid  bone  being 
removed  by  resorption  and  rebuilt  in  bone  with  Haversian  systems. 
This  process  is  shown  in  Fig.  <S2,  a  .section  through  a  growing  portion 


I'ERl  blL\  TA  L    M  KMliliANE 
Fi(i.  St 


109 


e% 


^^^ 


Osteoclast  absorption  of  bone  over  permanent  tooth :   Oc,  osteoclasts ;  B,  bone  of  crypt  wall 
F,  librous  tissue  of  follicle  wall ;  ^4,  ameloblasts.    (About  62  X  ) 

Fig..  85 


— Oc 


Osteoclasts  ;  Oc,  osteoclasts  ;  B,  bone.    (  About  66  X  ) 


110 


DENTAL   IIISTOLOCY   AND  OPEliAT I  V F.    DENTISTRY 


of  the  process  around  a  permanent  tooth.  A  lii<,f|i('r  p(»\vcr  (Fit,'.  83) 
shows  the  penetratinij^  fibers  and  the  formation  of  IIav<  isiiin-systein 
bone  witliout  fibers,  in  tiie  body  of  the  process. 

The  osteoclasis,  or  myelophi(iues,  are  bone-destroyiiif^f  cells  (Fig. 
84);  they  act  not  only  upon  bone,  but  also  uj)on  cementum  and  dentin. 
They  are  oval  cells,  often  as  much  as  .'JO  microns  in  diameter,  and  con- 
tain many  miclei — from  two  or  diree  to  fifteen  or  twenty.  They  are 
often  called  ^iant  cells.  The  osteoclasts  are  not  constantly  found  in  the 
membrane,  but  make  their  appearance  whenever  calcified  tissues  are  to 
be  destroyed.  In  order  for  them  to  act  upon  the  tissue  they  nuist  lie 
in  contact  with  its  surface,  and  therefore  the  first  step  in  absorption  of 
the  peridental  membrane  is  the  cuttin<r  off  of  the  fibers  einlx-ddcd  in 
the  bone  or  cementum.     Where  the  osteoclasts  act  upon  the  surface  of 


Fic.   80 


Record  in  the  calcified  tissue  of  an  uhsorption  repaired:  D.  dentin;  Cm,  ceinentuin  filling 
absorption  cavity.     (About  40   X  ) 


the  tissue  they  produce  bay-like  excavations,  in  which  they  lie,  and 
which  are  known  as  Howship's  lacuiue.  These  excavations  are  shown 
in  Fig.  87,  though  the  osteoclasts  have  disapj)eared.  In  Fig.  S(),  from 
a  ground  section,  the  basin-like  excavations  are  shown  filled  with  new- 
formed  cementum,  thus  leaving  in  the  tissue  the  recortl  of  an  absorp- 
tion repaired.  In  absorption  of  the  roots  of  the  temj)()rary  teeth  the 
osteoclasts  are  found  not  only  in  the  membrane  and  attacking  the 
surface  of  the  root,  but  all  through  the  medullary  spaces  in  the  bone, 
removing  the  temporary  alveolar  process. 

When  absorption  is  going  on  at  one  place  on  the  surface  of  a 
root  a  compensating  formation  of  cementum  is  going  on  at  another, 
so  that  not  all  of  the  fibers  of  the  membrane  are  cut  off.  This  is 
illustrated  by  sections  of  temporary  teeth  that  are  ready  to  be  shed 
(Fig.  87). 


PERI  DENT. \  L    MEMBRA  NE 


111 


Epithelial   Structures   of    the   Membrane.  -The    pcridciitiil    moiiil)rane 
contains  cellular  structures  of  epithelial  character  which  are  so  con- 


Fi<;.  87 


Root  of  a  temporary  incisor,  showing  absorption  and  rebuilding  of  cenientum  (from  sheep); 
G  gingiva;  D,  dentin;  Cm,  cementmii;  Ab,  absorption  cavity,  showing  Howship's  lacunse;  Cm', 
new-tormed  cementum.     (About  50  X ) 


spicuous    that   they   demand   consideration,    though    their   nature    and 
origin  are  not  as  yet  fully  understood. 

These  structures  were  first  well  illustrated  and  described  by  Dr. 
Black,  in  his  work  on  the  periosteum  and  peridental  membrane,  in  1887, 


112        DENTAL   lllSTOLOdY  AM)  OI'ICliATIVE   DENTISTRY 

Frr;.  88 


Diagram  of  glaml- Mf  jh  i  i^li  nt.i !  i. 
Fig.  89 


(<;.  V.  Black.) 


Ac 


Epithelial  structures  of  the  peridental  m.  i,      ,        from  sheep):   Fh.  fihrohlasts;   Ec,  epithelial 
structures;  Cb,  cementoblasts ;  Vnt,  ccuicritum  ;  D,  dentin.    (About  -168  X  ) 


riUil  DEX  TA  L    MEMIiliA  NE 


ii;] 


and  were  called  by  him  the  glands  of  the  peridental  membrane.  About 
the  same  time  von  Brunn^  described  what  are  probably  the  same  struc- 
tures, and  which  he  regarded  as  embryonal  remains  of  the  inner  layer 
of  the  enamel  organ,  which  he  described  as  growing  down  over  the 
surface  of  the  root.  These  structures  appear  as  cords  of  epithelial  cells 
arranged  in  die  form  of  a  network  winding  between  the  fibers  of  the 


Fic.  90 


Epithelial  structures  (from  sheep):  Fb,  fibroblasts;  Ec,  epithelial  structures;  Cb,  cementoblasts; 
Cm,  cemeiitum;  D,  dentine.    (About  700  X) 

membrane,  very  close  to  the  cementum  and  surrounding  the  root  almost 
to  the  apex.  Their  arrangement  is  illustrated  in  Fig.  88,  a  diagram  by 
Dr.  Black.  The  meshes  of  the  net  are  close  in  the  gingival  portion  of  the 
membrane,  but  grow  more  and  more  open  in  the  alveolar  portion.  They 
are  not  confined  to  the  membranes  of  young  teeth  or  the  temporary 
dentition,  as  Dr.  Black  has  shown  them  in  the  membrane  of  a  tooth  from 
a  man,  seventy  years  old,  though,  like  all  of  the  cellular  elements  of  the 
membrane,  they  become  less  numerous  as  age  advances.    These  struc- 


1  Archiv  f .  uiikros.  Anat. ,  1S87. 


114        DENTAL   nisrOLOCY  AM)  OI'EHATIV E  DESTISTUY 

tures  are  specially  well  shown  in  tlic  incinltiaiics  of  tlic  \)'\)s^  and  sheep. 
Fig.  89  shows  their  appearance  in  a  transverse  section  of  the  root  of  an 
incisor  of  a  sheep;  here  they  swing  ont  from  the  snrface  of  the  ceinen- 
tum  and  back  again  in  loops,  winding  in  and  ont  among  the  Hhers. 
Stndied  with  higher  powers  (Fig.  90),  they  are  seen  to  he  made  np  of 
epithelial  cells  with  large  oval  nuclei  which  react  to  the  characteristic 
epithelial  stains.  They  are  arranged  in  cords,  though  sometimes  what 
seems  to  be  a  lumen  of  a  gland  tul)ule  can  be  found  (Fig.  91).     The 


'-^5! 


-^MJMiHtwm.«wt:> 


Epithelial  structures:  Ec,  epithelial  coil.  ai)!,iarently  showing  a  lumen; 
Cm,  cementum;  D,  dentin.     (About  500  X) 


cords  are  invested  with  a  delicate  basement  membrane,  but  no  special 
relation  to  bloodvessels  has  been  demonstrated.  The  attempt  to  show 
their  connection  with  the  surface  epithelium  has  thus  far  failed.  As  the 
gingiva  is  approached  (Fig.  92),  they  seem  to  swing  out  from  the  sur- 
face of  the  root  and  are  lost  between  the  projections  of  the  epithelium 
lining  the  gingival  space.  There  is  evidence  that  these  structures  are, 
at  least  in  some  cases,  of  importance  as  the  primary  seat  of  pathological 
conditions  of  the  membrane. 


PERIDENTAL  MEMBRANE 
Fi(i.  1)2 


115 


Longitudinal  section:  Ep,  epithelium  lining  the  gingival  space;  Gg,  gingival  gland,  so  called, 
D,  dentin  ;  S,  Nasmyth's  membrane  ;  Du,  duct-liko  structure,  stretching  away  toward  the  gin- 
giva from  the  epithelial  cord,  seen  at  Ec :  Cm,  cementum,  separated  from  the  dentin  by 
decalcification.    (About  50  X  ) 


110         DESTAL   HISTOLOGY   AND  Ol'KRATlVl':   DESTISTUY 

Fig.  93. 


Fig.  94. 


Young  and  old  membranes  (from  sheep):  D,  dentin:  Cm,  cementum  :  CvO,  thickening  of  cemen- 
turn  to  attach  fibers  at  the  corner;  Pd,  peridental  membrane  ;  B,  boue  forming  the  wall  of  the 
alveolus  ;  P,  pulp.    (About  80  X  ) 


PERIDENTAL  MEM  lilt  AN  E  117 

Bloodvessels  and  Nerves  of  the  Membrane. — Bloodvessels. — The  hlood 
supply  of  tlio  peridental  membrane  is  very  abundant.  Several  vessels 
enter  the  membrane  from  the  bone  in  the  apical  region.  These  arteries 
])raneh  and  divide,  fonniiio;  a  rieh  network,  from  which  the  ca}>illary  ves- 
sels are  given  off.  The  arterial  network  is  constantly  receiving  vessels 
which  enter  the  membrane  through  Haversian  canals  opening  on  the  wall 
of  the  alveolus,  and  in  this  way  the  size  of  the  vessels  passing  oeclusallv 
is  maintained.  Arterial  vessels  also  enter  the  membrane  over  the  border 
of  the  process.  This  double  or  triple  supply  of  the  membrane  is  impor- 
tant, as  it  maintains  the  health  of  the  membrane  when  the  supply  entering 
through  the  apical  region  is  entirely  cut  oif  by  alveolar  abscess.  While 
the  arterial  supply  of  the  membrane  is  very  rich,  the  capillaries  in  the 
membrane  are  comparatively  few.  This  is,  however,  a  characteristic 
of  connective-tissue  membranes. 

The  nerves  of  the  peridental  membrane  have  not  been  sufficiently 
studied  to  be  described  in  detail.  Six  to  eight  medullated  nerve  trunks 
enter  the  apical  region  in  company  with  the  bloodvessels,  and  they 
receive  other  trunks  through  the  wall  of  the  alveolus  and  over  the  border 
of  the  process,  but  the  manner  of  their  distribution  and  the  nature  of 
their  endings  are  not  known. 

The  Changes  which  Occur  in  the  Membrane  with  Age. — When  a  tooth 
is  erupted  the  roof  of  the  bony  crypt  in  which  it  was  enclosed  in  the 
body  of  the  bone  is  removed  by  absorption  and  the  crown  advances 
through  the  opening.  The  diameter  of  the  alveolus  at  that  time  is, 
therefore,  greater  than  the  greatest  diameter  of  the  crown,  and  the 
peridental  membrane  which  fills  the  space  is  very  thick.  By  the  forma- 
tion of  bone  on  the  wall  of  the  alveolus  and  the  formation  of  cementum 
on  the  surface  of  the  root,  the  thickness  of  the  membrane  is  reduced. 
In  the  young  membrane  most  of  the  large  bloodvessels  are  found  in 
its  outer  half,  forming  a  rather  defined  vascular  layer  near  its  centre. 
In  the  old  membrane  most  of  the  bloodvessels  are  found  very  close  to 
the  surface  of  the  bone,  often  lying  in  grooves  in  its  surface.  Both 
young  and  old  membranes  are  illustrated  in  Figs.  93  and  94,  which  are 
taken  from  the  temporary  teeth  of  a  sheep,  one  just  after  eruption  and 
the  other  shortly  before  the  time  of  shedding. 


CHAPTER    III 
ANTISEPSIS  IN  DENTISTRY 

Bv  JAMES  TRUMAN,  D.D.8.,  LL.D. 

Antisepsis  has  now  become  recognized  as  of  \'ital  importance  in  all 
operations  connected  with  the  human  organism.  The  oral  cavity, 
with  its  contents,  has  been  considered,  of  recent  years,  one  of  the  most 
important  factors  in  producing  disease,  and  hence  both  dental  and 
medical  practitioners  have  realized  that  hygienic  and  prophylactic 
measures  must  begin  with  this,  the  vestibule  of  the  entire  system.  It 
is  here  that  the  pathogenic  organisms  find  a  prolific  culture  field  and 
with  the  possible  result  of  equally  infecting  many  important  organs. 
That  this  was  not,  in  earlier  dental  practice,  fully  recognized  is  due  to 
the  fact  that  the  part  played  by  bacteria  was  not  known  thirty  years 
ago,  as  it  is  now,  hence  cleanliness,  as  then  understood,  was  held  to  be 
sufficient.  This,  however,  will  not  meet  the  requirements  of  the 
present,  and  the  dental  practitioner  neglecting  to  avail  himself  of  all 
means  and  appliances  necessary  to  affect  antisepsis  is  assuming  a  grave 
responsibility.  The  skepticism  which  formerly  prevailed  as  to  the  value 
of  antiseptic  measures  had  its  origin  in  the  prevailing  idea  that  the  oral 
fluids  were,  with  ordinary  cleanliness,  sufficient  to  prevent  infection. 

This  has  never  been  proved  through  laboratory  experiments,  but  clini- 
cal observation  and  long  experience  have  demonstrated  that  injuries  in 
the  mouth  ordinarily  heal  rapidly.  It  seems  unreasonable  to  suppose  that 
a  fluid  peculiarly  subject  to  fermentation  should  have  this  effect,  and  this 
has  led  some  to  ascribe  it  to  a  vital  influence.  ]\Iiller^  says  of  this:  "It 
is  a  very  fortunate  provision  that  the  gums  in  a  healthy  state  offer  so 
powerful  a  resistance  to  the  invasion  of  the  germs  of  most  iiifrcfious  rJis- 
eases.  For  this  reason  a  wound  in  the  gums  may  be  followed  by  scarcely 
any  reaction  whatever,  while  a  similar  wound  on  the  hand  with  the  same 
instrument  may  produce  most  disastrous  results.  It  has  been  attempted 
to  account  for  this  fact  on  the  supposition  that  the  saliva  has  an  anti- 
septic action,  in  evidence  of  which  we  are  often  reminded  that  dogs  lick 
their  wounds,  and  that  these  heal  rapidly.  .  .  I  doubt  if  there  is 
anyone  who  would  wish  us  to  believe  that  the  dead  saliva  has  even  the 
slightest  antiseptic  properties,  in  consideration  of  the  fact  that  saliva, 

J  Dental  Cosmos,  July,  1831. 

(118) 


/1/V77.s'7?/'.SV.S'  IX   DENTISTRY  119 

especially  when  it  contains  much  organic  matter,  readily  j)utrcfies.  If 
the  saliva  possesses  any  such  property,  it  must  be  sought  for  in  its  living 
histological  elements — i.  e.,  in  the  living  leukocytes  or  phagocytes.'" 

AVhile  it  is  true  that  there  exists  a  degree  of  exemption  from  serious 
results,  leading  to  indifference  and  careless  management  of  cases,  it  is 
e(iually  true  that  infection  has  resulted  in  the  experience  of  almost 
every  operator  in  dentistry. 

Prior  to  the  period  when  Lister  announced  that  all  operations  in 
surgery  should  be  performed  antiseptically,  and  made  modern  sin-gery 
possible,  this  ignorance  was  excusable;  but  at  the  present  time,  with  the 
accumulated  knowledge  in  bacteriology,  it  should  be  impossible  for  any 
dental  operator  to  neglect  the  procedures  under  this  head  considered 
absolutely  essential  for  the  general  surgeon. 

The  difficulties  attending  antisepsis  in  dentistry  far  exceed  those  in 
other  branches  of  surgery.  The  dentist  is  necessarily  obliged  to  meet 
conditions  hourly  that  seem  to  preclude  absolute  freedom  from  sources 
of  contamination.  If  he  were  to  take  the  same  precautionary  measures 
now  regarded  as  necessary  for  the  surgeon,  he  would  find  practice  almost 
impossible.  While  this  is  true,  it  does  not  follow  that  every  ett'ort 
should  not  be  made  to  approach  absolute  surgical  cleanliness. 

The  usual  methods  employed  to  accomplish  this,  while  valuable  to 
a  limited  extent,  are  by  no  means  equal  to  what  could  readily  be  secured 
without  consuming  much  time  or  patience.  The  dentist  is  usually  sat- 
isfied that  he  has  fulfilled  all  antiseptic  precautions  when  he  has  dipped 
his  instrument  in  some  antiseptic  fluid,  generally  carbolic  acid.  Little 
or  no  attention  is  paid  to  the  possibility  of  infection  from  the  rubber 
dam,  towels,  hands,  and  the  variety  of  instruments  that  enter  into  dental 
operations.  Some  of  the  latter,  as,  for  instance,  the  separator,  are  more 
liable  to  carry  infection  than  the  excavator,  the  one  generally  regarded 
as  most  important. 

The  appliances  ordinarily  in  daily  use  are  the  rubber  dam,  excava- 
tors, broaches,  pluggers,  clamps,  ligatures,  separators,  drills,  hand- 
pieces, napkins,  and  forceps.  It  is  safe  to  assume  that  but  few  of  these 
will  receive  any  attention  beyond  ordina.ry  washing.  The  rubber-dam 
is  too  often  used  as  it  is  furnished  by  the  manufacturer.  If  an  attempt 
at  cleanliness  is  made,  it  consists  in  washing  the  dam  in  cold  or  warm 
water,  this  being  regarded  as  sufficient. 

The  boiling  of  the  rubber  in  water  has  the  effect  of  reducing  the 
absolute  tenacity  of  the  material.  The  continuation  of  the  boiling 
for  fifteen  minutes,  while  it  does  not  seem  to  aftect  immediately  the 
elasticity,  renders  the  rubber  apt  to  tear,  a  very  objectionable  feature. 
If  kept  for  a  few  da^'s  it  deteriorates  rapidly.    The  writer  has  tested 

1  For  an  elaborate  study  of  this  problem  see  Experimental  Study  of  the  Different  Modes  of 
Protection  of  the  Oral  Cavity  against  Pathogenic  Bacteria,  by  Arthur  C.  Hugenschmidt,  M.D., 
Dental  Cosmos,  xxxviii,  p.  797. 


120  ANTISEPSIS  IN  DENTISTRY 

this  at  various  periods  of  Ixjilinf^  without  any  marked  difference  in 
results.  The  boiHiig  of  rubber  cannot,  therefore,  })e  recommended. 
This  is  to  be  regretted,  for  it  is  evident  that  tlie  rubber,  as  it  comes 
to  the  dentist  in  sheets,  is  a  \ery  unsafe  material  to  place  in  the  mouth. 
To  meet  this  objection  there  remains  but  one  remedy,  and  that  is  thor- 
ough washing  in  water  with  a  good  antiseptic  soap.  This  has  no  injurious 
effect  on  the  material,  but  while  this  is  true,  it  cannot  be  regarded  as 
effective  sterilization,  but  with  other  aids  may  answer  the  purpose. 

The  dam  should  never  be  applied  without  first  bathing  the  gingivae 
of  the  teeth  to  be  covered  by  the  rubber  with  a  good  antiseptic  wash. 
The  most  effectual  is,  probably,  a  1  per  cent,  alcoholic  solution  of 
hydronaphthol.  Upon  the  removal  of  the  dam  this  bathing  should 
be  repeated,  saturating  thoroughly  the  free  margin  of  the  gums.  This 
is  especially  recpiired  after  the  use  of  ligatures  and  clamps. 

It  is  needless  to  add  that  the  rubber  should  never  be  used  a  second 
time  on  a  different  patient. 

\Vlien  it  is  remembered  that  this  is  passed  between  teeth  and  usually 
forced  up  under  gingival  margins  with  ligatures,  or  clamps,  fre(juently 
lacerating  the  surface,  it  becomes  evident  that  the  possibility  of  infection 
is  always  present.  If  infection  does  not  occur  from  the  rubber,  it  is 
almost  certain  to  produce  a  wound  in  a  locality  extremely  favorable  for 
the  growth  of  pathogenic  germs.  The  result  is  innumerable  lesions 
that  may  extend  to  pericemental  inflammations.  The  great  increase 
in  the  past  twenty-five  years  of  gingival  inflammations  subsequent  to 
operations  in  mouths  of  more  than  ordinary  health  must  be  partly 
ascribed  to  this  cause. 

Excavators  ordinarily  receive  the  most  attention,  and  yet,  when  their 
use  is  considered,  they  possibly  require  the  least.  It  is  rarely  necessary 
to  use  the  excavator  outside  of  a  cavity,  where  infection,  if  at  all  pos- 
sible, would  do  the  least  harm,  for  the  continual  washing  of  the  cavity, 
as  the  operator  proceeds,  reduces  the  danger  to  a  minimum.  Broaches 
and  all  instruments  intended  to  enter  the  pulp  canals,  require  the  most 
careful  attention,  and  this  applies  with  equal  force  to  drills;  yet  it  is 
fe.ired  that  both  of  these,  loaded  though  they  are  with  septic  matter, 
receive  but  indifferent  care.  When  the  dangerous  possibilities  which 
mav  result  from  this  negligence  are  considered,  it  I)econies  a  serious,  if 
not  a  criminal  offence.  The  difficulty  in  making  these  instruments  germ- 
free  and  in  keeping  them  from  becoming  contaminated  is  fully  appre- 
ciated; yet  the  effort  must  be  made,  and  it  is  not  a  difficult  procedure, 
nor  does  it  require  a  large  consumption  of  time — an  important  item  to 
the  dental  operator. 

Pluggers  cannot  be  regarded  as  a  source  of  infection.  They  are 
used  solely  in  connection  with  metal,  and  therefore  strict  cleanliness 
is  all  that  is  absolutely  required.  It  is  fortunate  that  this  is  so,  for 
these  instruments  require  unusual  care  to    protect   them    from  rust. 


ANTISEPSIS  IN  DENTISTRY  121 

Hence  immersion  in  an  antiseptic  fluid  may  he  deleterious  and  not 
required. 

Separators — and  under  this  head  are  included  metal  ones  with  screw 
attachments  and  wedges — require  special  attention,  but  probably  receive 
the  least.  They  should  be  made  as  nearly  sterile  as  possible  before 
their  use  upon  a  patient. 

Hand-pieces,  of  the  various  kinds  in  use,  are  probably  the  most 
difficult  to  keep  thoroughly  clean.  While  they  do  not  come  in  direct 
contact  with  the  tissues  of  the  mouth,  they  may  indirectly,  by  contam- 
inating the  hands,  produce  unpleasant  results.  Frequent  taking  apart 
and  boiling  are  essential,  and  should  not  be  omitted. 

Napkins  from  the  ordinary  wash  have  been  and  are  used  with  con- 
fidence that  no  bad  results  from  use  can  follow.  If  the  laundry  is  con- 
fined to  the  home,  this  may  ordinarily  be  true,  but  the  indiscriminate 
mingling  of  washes  indulged  in  by  the  commercial  laundryman  is 
always  a  menace  to  health.  Where  napkins  of  the  latter  character  are 
to  be  used  they  should  be  subjected  to  the  sterilizing  process. 

The  chair  occupied  by  a  variety  of  patients  may  be  a  source  of  dis- 
ease, and  should  be  carefully  cleansed,  especial  care  being  taken  with 
the  head-piece.  The  latter  should  be  covered  with  a  clean  napkin,  to 
be  changed  for  every  patient. 

The  cuspidor,  where  the  fountain  is  not  used,  is  ordinarily  an  abom- 
ination, for  here,  if  anywhere,  will  carelessness  be  manifest.  There  can 
be  no  excuse  for  this,  as  thorough  daily  scalding  with  boiling  water  and 
the  use  of  antiseptics  will  keep  it  measurably  free  from  unpleasant 
consequences. 

Glasses  require  to  be  thoroughly  boiled  both  before  and  after  use. 
Boiling  should  never  be  neglected  with  ejector  tubes,  either  metal 
or  glass,  glass  being  generally  used.  Hard  boiling  in  water  for  twenty 
minutes  should  be  sufficient. 

The  lancet  is  an  instrument  demanding  especial  care,  as  it  may  become 
a  dangerous  source  of  infection. 

This  instrument  should  be  thoroughly  sterilized  by  boiling  in  water 
in  which  sodium  bicarbonate  has  been  added.  This  must  never  be 
neglected,  mere  dipping  in  carbolic  acid,  or  a  milder  antiseptic,  has 
very  little  value. 

The  fact  that  the  lancet  must  frequently  be  employed  on  infants 
during  the  eruptive  stage  of  the  deciduous  teeth,  demands  special  care, 
and  before  attempting  its  use  the  gums  should  be  thoroughly  washed 
with  an  antiseptic  of  a  non-escharotic  character.  The  difficulty  attend- 
ant on  lancing  these  teeth  in  private  families,  where  this  is  generally 
required,  can  be  in  a  measure  overcome  by  the  preparatory  boiling 
process  in  the  office  and  careful  wrapping  the  blade  in  antiseptic  cotton, 
and,  before  its  final  use,  dipping  it  in  an  antiseptic  solution,  1  per 
cent,  solution  of  formalin  preferred. 


122 


ANTISEPSIS  IX  DENTISTRY 


Fig.  95 


The  forceps  employed  in  extraction  should  he  so  constructed  as  to 
render  the  blades  readily  scj)aral)lc  at  tiie  joint,  and  they  should  be 

boiled  in  soda  bicarbonate  solution  for  an 
hour.  The  recorded  cases  of  infection 
from  these  instruments  render  this  care 
imperative  in  all  instances. 

Fig.  95  shows  a  convenient  form  of 
apparatus  for  sterilizing  ordinary  dental 
instruments  by  a  l)oiling  soda  solution. 

The  writer  has  found  that  a  half  to  a 
teaspoonful  of  sodium  bicarbonate  to  a 
pint  of  water,  and  kept  at  boiling  temper- 
ature for  fifteen  minutes,  is  amply  suffi- 
cient for  sterilization  and  with  no  injury 
to  instruments.  The  amount  of  sodium 
bicarbonate  to  be  used  will  depend  on  the 
character  of  the  water  in  a  given  locality. 
Abbott^  in  his  valuable  chapter  on  steri- 
lization, thus  briefly  describes  those  agents 
which  will  "prove  of  value  in  rendering 
infectious  materials  harmless;  they  are: 
Heat,  either  l^y  burning,  by  steaming  for 
from  half  an  hour  to  an  hour,  or  by 
boiling  in  a  2  per  cent,  sodium  carbonate 
solution  for  fifteen  minutes;  3  to  4  per  cent,  solution  of  commercial 
carbolic  acid;  milk  of  lime  and  a  solution  of  chlorinated  lime  con- 
taining not  less  than  0.25  per  cent,  of  perchlorine."  It  must  be  evident 
that  the  only  available  method,  in  this  list,  for  the  dentist  is  by  boil- 
ing in  sodium  carbonate  solution. 

ORAL  DISEASES  AND  THEIR  TRANSMISSION 

The  possibility  of  carrying  disease  from  one  person  to  another  seems  so 
self-evident  that  it  ought  not  to  require  more  than  a  word  of  caution, 
and  yet  it  is  clear  that  the  attention  given  to  this  source  of  danger  is  by 
no  means  commensurate  with  the  risks  assumed  constantly  in  practice. 
The  peculiarly  transitory  character  of  much  of  dental  practice  precludes 
the  possibility  of  any  previous  history  of  patients,  and  therefore  every 
one  should  be  regarded  as  a  possible  source  of  infection. 

Diseases  the  result  of  pathogenic  bacteria  independent  of  possible 
external  infection  are  now  in  the  main  well  understood,  but  by  no  means 
equally  appreciated  by  medical  practitioners,  nor  are  they  properly  con- 
sidered by  dental  operators.     ]\Iiller  states  that  "  many  facts  favor  the 


Downie  steam  sterilizer. 


I  The  Principles  of  Bacteriology,  1902. 

*  The  Microorganisms  of  the  Human  Mouth,  p.ige  275. 


ORAL  DISEASES  AND  THEIR   TRANSMISSION  123 

.supposition  that  a  considerable  numl)er  of  pathop;enic  microorganisms 
may  tiirive  in  the  juices  of  the  mouth  without  showing  in  tlieir  vital 
manifestations  any  distinction  from  the  common  parasites  of  the  oral 
cavity  as  long  as  the  mucous  membrane  remains  intact.  If,  however, 
the  soft  tissues  have  been  wounded,  as  in  extraction,  or  if  the  resistance 
of  the  mucous  membrane  has  been  impaired,  these  organisms  may  gain 
a  point  of  entrance  and  thus  become  able  to  manifest  their  special 
actions."  This  fact,  now  well  recognized,  is  being  constantly  demon- 
strated in  the  use  of  the  various  appliances  that  may,  through  careless 
handling,  injure  the  mucous  membrane.  So  much  is  this  the  case  that 
a  large  proportion  of  gingival  inflammations  have  undoubtedly  had 
their  origin  from  this  cause.  It  has  come  under  the  observation  of  the 
writer  that  injuries  thus  received,  although  apparently  unnoticed  by 
dentist  or  patient,  have  resulted  in  the  course  of  forty-eight  hours  in 
very  disturbing  pericementitis,  confusing  to  the  operator  and  very  painful 
to  the  patient.  The  necessity  for  such  antiseptic  precautions  here  as  are 
taken  in  general  surgery  is  almost  entirely  overlooked.  Before  placing 
the  coffer-dam,  the  clamp,  or  ligature,  that  portion  of  the  mouth  should 
be  thoroughly  washed  with  an  antiseptic  -solution  and  an  effort  made 
to  render  the  appliances  equally  sterile,  or  at  least  to  inhibit  develop- 
ment for  a  definite  period.  (See  Treatment  of  Rubber  Dam.)  The 
evidence  is  abundant  that  many  cases  of  pyorrhea  alveolaris  have 
had  their  origin  from  this  careless  indiff'erence  to  accepted  and  necessary 
precautions. 

The  mouth,  as  a  source  of  disease  to  the  general  system,  does  not 
properly  belong  to  this  article  to  discuss,  but  its  importance  cannot  be 
overlooked.  Dental  writers  have  devoted  much  attention  to  this  sub- 
ject. It  is  for  the  dentist  to  understand  that  he  is,  to  a  large  degree, 
responsible  for  the  general  health  of  his  patient  as  far  as  the  mouth  is 
concerned,  and  he  should  insist  on  prophylactic  measures  that  will  at 
least  reduce  this  source  of  disease  to  a  minimum.  The  constant  danger 
of  what  IMiller  aptly  calls  "auto-infection"  from  the  collection  and 
propagation  of  pathogenic  bacteria  in  the  fluids  of  the  mouth  should 
suggest  to  the  dentist  constant  efforts  to  effect  the  removal  of  all  deposits 
on  the  enamel,  gingival  margins,  tongue,  and  mucous  membrane.  This 
line  of  study  will  bring  about  in  the  future  an  entirely  different  dentistry 
as  to  hygiene  and  prophylaxis  from  that  practised  at  the  present  time. 

The  pulp  of  a  tooth  is  not  ordinarily  regarded  as  a  point  of  infec- 
tion, and  yet  it  is  well  known  to  be  a  serious  menace  to  the  health  of 
an  individual.  Israel,  quoted  by  iMiller,^  asserts  that  "the  root  canal 
furnishes  a  point  of  entrance  even  for  the  ray-fungus,  actinomyces, 
and  in  one  case  the  microscopic  examination  revealed  the  elements  of 
this  organism  in  the  canal  of  a  pulpless  tooth."    ^^llen  it  is  considered 

1  The  Microorganisms  of  the  Human  ^louth,  p.  285. 


124  ANTISEPSIS  IX   DENTISTRY 

that  some  individuals  have  decomposed  jjulps  in  a  nnmher  of  teeth  at 
the  same  time,  and  tre<|uently  a  seore  of  dead  and  broken  roots,  sendinj^ 
out  their  infectious  material,  it  is  not  surprisini^;  that  disease  of  a  serious 
nature  may  supervene.  While  there  is  no  record  of  cases  coming  within 
the  observation  of  the  writer  of  pulps  produeini^  pyemia  directly,  it 
is  a  well-known  fact,  supported  by  a  lotii;'  list  of  recorded  cases,  that 
alveolar  abscess,  with  its  concentration  of  putrid  material,  is  liable 
to  be  followed  by  blood  poisoninj^. 

There  is  no  question  that  diseases  of  the  digestive  organs,  of  the 
lungs — in  fact,  of  all  the  organs  of  the  body — may  be  produced  by 
infected  material  germinated  in  the  mouth,  and,  indeed,  through  sputum 
ejected,  may  affect  individuals  remotely  situated. 

Miller,*  in  considering  this  portion  of  the  subject,  says:  "We  know 
that  under  certain  circumstances  saccharomycetes  may  directly  colonize 
in  the  mucous  membrane  of  the  mouth,  and  that  in  the  mouths  of 
enfeebled  individuals  bacteria  may  occasionally  obtain  a  foothold. 
The  mucous  membrane  of  the  mouth  and  pharynx  is  especially  sus- 
ceptil)le  to  the  action  of  certain  germs  of  infection  (those  of  diphtheria, 
syphilis,  etc.),  and  large  portions  of  the  mucous  membrane  and  the 
submucous  tissue  may  be  wholly  destroyed  by  parasitic  influences." 

The  extended  use  of  fixed  dentures  in  the  mouths  of  patients,  of 
so-called  bridge-work,  and  crowns  of  varied  character,  are  prolific 
in  mouth  disorders.  The  removable  bridge-piece,  in  a  measure,  over- 
comes liability  to  infection,  provided  the  patient  is  properly  instructed 
in  its  use  and  care,  but  the  average  patient  has  no  real  conception  of 
the  danger  from  infection  from  this  source.  It  becomes  the  duty  of 
every  dentist,  upon  inserting  such  a  piece,  to  insist  on  careful  anti- 
septic methods  of  cleanliness. 

There  is  a  phase  of  this  subject  that  requires  more  extended  inves- 
tigation. Inflammations  of  the  mouth  are  not  infrequent  where  great 
swelling  is  present.  This  may  be  observed  around  the  lower  third 
molars  with  no  explainable  cause  in  dead  pulps,  overlapping  mucous 
membrane,  retarded  eruption,  or  malpresentation.  It  is  evidently 
produced  by  bacterial  invasion,  but  has  not  always  yielded  to  anti- 
septic measures,  and  at  times  has  resulted  in  abscess  entirely  independent 
of  pulp  devitalization. 

Crowns  improperly  placed  are  a  continued  source  of  disease,  result- 
ing not  only  in  the  loss  of  the  roots  upon  which  these  are  placed,  but 
in  gingival  and  peridental  inflammations,  involving  not  only  local 
pathological  conditions,  but  extensive  gastric  disturbance. 

A  recent  report  of  three  cases  by  Dr.  John  A.  AlcClain'  in  the  medical 
practice  of  Dr.  M.  G.  Tull  is  interesting  as  indicating  possibilities. 
The  first  case  was  an  extensive  swelling  posterior  to  the  lower  third 

•  The  Microorganisms  of  the  Human  Mouth,  p.  295. 
-  International  Dental  .Journal,  October,  1900. 


INFECTION   FROM  MOUTH    TO  MO  I  Til  125 

molar.  He  could  not  coiiiiect  it  with  that  tooth,  and  suspt'ctcd  auto- 
infection,  lie  had  cultures  made  with  negative  re.sult,s.  Hi.s  theory 
was  that  it  was  diphtheritic;  and,  although  laboratory  evidence  wa.s 
wanting,  he  determined  to  inject  antitoxin.  This  injection  was  fol- 
lowed in  twenty-four  hours  by  an  entire  reduction  of  the  sweilinc- 
All  other  efforts  had  previously  failed  to  effect  any  result.  Two  other 
similar  cases  yielded  to  the  antitoxin  treatment  in  the  same  speedy 
manner.  If  this  can  be  regarded  as  something  more  than  a  coincidence 
in  practice,  it  may  lead  to  an  explanation  of  many  similar  anomalous 
pathological  cases  arising  posterior  to  the  third  inferior  molar,  yet 
apparently  not  connected  with  it.  Similar  conditions  have  been  the 
cause  of  much  uncertain  diagnosis  and  still  more  empirical  ti'eatment. 

The  more  the  writer  has  considered  this  subject  the  more  important 
it  has  appeared;  and  he  is  convinced  that,  when  the  proper  prophy- 
lactic measures  come  into  use  for  the  prevention  of  tuberculosis,  in  all  its 
protean  forms,  antisepsis  of  the  mouth  will  be  given  primary  importance. 

The  fact  is  very  apparent  that  very  little  attention  is  given  to  anti- 
sepsis of  the  mouth  in  hospital  treatment,  and  what  is  equally  remark- 
able, our  health  authorities,  in  all  cities  in  this  country,  have  not  until 
recently  awakened  to  its  importance  in  connection  with  the  public 
schools.  The  authorities  are  usually  quite  sufficiently  active  as  to 
the  general  health  of  the  children,  but  pay  not  the  slightest  attention 
to  the  condition  of  the  mouths  and  necessary  dental  care.  When  this 
care  is  given  one  of  the  open  doors  to  tuberculosis  will  be  closed. 


INFECTION  FROM  MOUTH  TO  MOUTH 

Infection  from  mouth  to  mouth  through  instruments  is  a  difficult 
matter  to  prove  by  cases,  but  theoretically  there  can  be  no  cause  for 
disputation.  The  question  will  always  arise.  Was  the  lesion  occasioned 
by  auto-infection  or  by  transmission  ?  The  answer  can  rarely  be  given 
with  the  assurance  desirable.  In  one  instance,  at  least,  in  the  writer's 
experience  the  origin  was  clearly  traceable.  This  was  in  a  patient  of  the 
better  class,  presenting  for  treatment  in  the  clinic  of  the  Dental  Depart- 
ment of  the  tjniversity  of  Pennsylvania.  Her  teeth  were  remarkable  for 
structure,  regularity,  and  cleanliness;  gums  perfectly  healthy.  Necrosis 
of  the  anterior  alveolar  plate  was  threatened  when  first  seen,  and  finally 
resulted  in  the  entire  destruction  of  the  alveolar  border  and  all  the 
anterior  upper  teeth,  but  did  not  involve  the  maxilla.  The  history 
of  the  case  as  given  was  that  a  bicuspid  had  been  extracted  from  the 
right  superior  region  by  a  dentist  notorious  for  his  uncleanly  habits. 
Not  long  thereafter  the  patient  noticed  a  serious  inflannnation.  These 
symptoms  indicated  a  syphilitic  infection,  and  the  family  physician  was 
consulted,  who  insisted  that  no  history  of  this  disease  existed  and  that 


126  ANTI^EI';Sl;S  IN   DESTISTHY 

iiitVctioii  iiuLst  1)0  the  cause.  The  patient,  tlir()ii<i;li  his  treatment  and 
that  ifiven  locally,  recovered,  but  was  forced  to  wear  an  artificial  sul)- 
stitute. 

Cases  of  infection  throufjh  extraction,  either  h\  the  forceps  or  after- 
infection  from  the  mouth,  miti;ht  be  quoted  almost  indefinitely.  Miller 
reports  case  upon  case — in  fact,  the  accumulation  of  these  has  become 
of  serious  moment;  and  yet,  in  the  face  of  undisputed  facts,  dentists 
will  continue  to  extract  teeth  frecjuently  without  any  precautions,  or, 
at  most,  relying  on  simple  washing  of  the  instrument.  Some  German 
writers  contend  that  antisepsis  after  extraction  is  wholly  unnecessary, 
as  the  clot  formed  is  a  sufficient  protection.  This  is  certainly  not  true 
in  all  cases.  It  is  not  always  the  fact  that  a  clot  is  formed,  or  when 
formed  that  it  serves  an  antiseptic  purpose.  One  of  the  most  serious 
cases  that  has  fallen  to  the  writer  to  treat  was  that  of  necrosis  of  the 
superior  maxilla  involving  destruction  of  the  right  side,  taking  in  all 
the  teeth  from  the  third  molar  to  the  lateral,  the  floor  of  the  antrum, 
a  portion  of  the  nasal  bones,  and  half  of  the  hard  palate.  This  was  the 
result  of  the  extraction  of  the  third  molar  by  a  specialist  before  the 
days  of  antisepsis;  whether  it  was  the  result  of  infection  is  difficult 
to  determine.  In  the  opinion  of  the  writer,  no  extraction  should  be 
attempted  until  the  instruments  used  have  been  thoroughly  sterilized  by 
boiling.  Before  the  forceps  are  applied  the  parts  surrounding  the  tooth 
should  be  well  washed  with  an  antiseptic  solution.  After  the  extraction 
the  socket  should  be  syringed  with  sterilized  water,  followed  by  some 
powerful  disinfectant.  In  view  of  the  serious  results  probable  in  this 
operation  there  is  no  longer  any  excuse  for  injuries  resulting  from 
infection,  and  a  suit  for  malpractice  could  be  well  sustained  against  an 
individual  who  had  failed  to  observe  the  well-understood  methods  of 
antisepsis,  while  no  intelligent  practitioner  could  conscientiously  appear 
on  behalf  of  the  defendant. 


EXTERNAL  INFECTION 

The  danger  to  the  operator  from  external  infection  from  instruments 
is  a  constant  menace;  the  constant  use  of  these  with  general  freedom 
from  serious  results,  however,  leads  to  a  degree  of  carelessness  not  w^ar- 
ranted  by  the  ever-present  danger  from  wounds.  There  is  more  real 
danger  to  the  operator  from  this  source  than  to  the  patient.  All  the 
excavators,  drills,  and  broaches  are  hourly  in  contact  with  infectious 
matter,  and  it  requires  but  a  slight  wound  to  produce  any  of  the  possi- 
bilities of  blood  poisoning.  The  operator  should  be  on  constant  guard 
in  this  respect,  upon  the  slightest  abrasion  immediately  taking  measures, 
to  destroy  all  possibility  of  infection  from  germs  that  may  have  been 
introduced  into  the  wound.     This  should  at  once  be  carefully  washed 


JMI'LANTATION  AND  TliANiSl'LANTATJON  127 

and  an  cscliarotic  employed,  hurninn;  the  parts.  For  tlil.s  purpose  zinc 
clilorid  or  carbolic  acid  are  probably  the  best  agents  to  use,  followed  by 
an  antiseptic.  The  latter  should  be  fre(|uently  renewed.  Experience 
has  demonstrated  the  value  of  turpentine  in  the  various  mechanical 
shops  where  this  agent  has  been  for  many  years  in  common  use  for 
wounds  from  rusted  iron,  the  possibility  of  trismus  resulting  from  such 
injuries  being  well  understood.  The  writer  has  used  this  agent,  after 
burning  the  wound,  almost  to  the  exclusion  of  other  antiseptics. 

An  illustration  of  the  ever-present  danger  from  wounds  occurred 
to  a  friend  of  the  writer's,  one  of  the  many  young  women  who  have 
graduated  in  dentistry  in  this  country.  She  accidentally  wounded  her 
hand  by  a  drill,  and  regarded  it  as  of  no  moment.  The  result  was  severe 
blood  poisoning  that  for  two  years  kept  her  hovering  between  life  and 
death.  After  suffering  from  severe  metastatic  abscesses,  she  was  finally 
restored  to  partial  health,  but  with  her  constitution  shattered  and  her 
practice  ruined  for  the  time  being. 


IMPLANTATION  AND  TRANSPLANTATION 

Previous  to  the  recognition  of  the  importance  of  antisepsis,  the  den- 
tists of  that  period  had  a  very  natural  objection  to  reimplanting  teeth; 
the  practice  of  transplantation  was  then  practically  an  unknown  oper- 
ation. The  danger  of  the  operation  was  appreciated,  but  the  reason 
was  not  then  comprehended.  When  the  study  of  bacteriology  had 
advanced  to  a  science  through  the  labors  of  Pasteur,  Koch,  and  a  host  of 
investigators,  the  reasons  for  this  fear  were  explained,  and  the  con- 
ditions necessary  to  avoid  unpleasant  results  being  understood,  the 
danger  from  infection  was  changed  to  absolute  security.  It  is,  moreover, 
to  be  ever  borne  in  mind  that  but  for  this  knowledge  implantation  and 
transplantation  could  today  not  be  practised  without  the  probability  of 
serious  results. 

A  case  illustrating  this  point  occurred  prior  to  the  knowledge  of  anti- 
sepsis in  the  hands  of  a  well-known  dentist.  He  had  removed  three 
teeth  and  successfully  reimplanted  them  for  the  cure  of  a  violent  case  of 
neuralgia  presumably  due  to  calcific  depositions  in  the  pulp  and  about 
the  external  portions  of  the  roots.  Relief  was  so  immediate  that  upon 
return  of  the  pain  another  tooth  was  attempted.  Trismus  followed, 
resulting  in  the  death  of  the  patient.  It  is  safe  to  assume  that  this 
unfortunate  result  could  not  have  happened  under  the  antiseptic  care 
usual  at  the  present  time,  even  imperfect  as  it  frequently  is. 

To  accomplish  antisepsis  in  this  operation  the  greatest  care  is  neces- 
sary. In  transplantation,  teeth  being  procured  from  other  mouths, 
the  danger  is  necessarily  much  increased.  The  method,  adopted  by 
some,  of  immersing  these  teeth  in  various  antiseptic  fluids  cannot  be 


128  ANT  I  SEPSIS  /.V  DENTISTRY 

commended.  Miller^  says  of  this:  "It  is  generallv  accepted  that  the 
operator  takes  every  possible  precaution  when  he  allows  the  tooth 
to  lie  for  one-half  to  one  hour  in  a  1  per  cent,  solution  of  carbolic  acid, 
or  in  a  1  to  i ()()()  solution  of  bichlorid  of  mercury.  .  .  ,  In  order 
to  reach  bacteria  that  may  have  penetrated  into  the  lacuna'  or  chance 
vascular  canals,  a  much  lon<;er  action  of  the  antiseptic  is  necessary, 
and  to  be  perfectly  certain  that  we  have  accomplished  our  object  we 
should  have  recourse  to  boiling  water." 


AGENTS  USED  FOR  STERILIZATION 

The  necessity  for  a  definition  of  the  words  used  in  sterilization  may 
not  be  apparent  to  the  average  reader,  but,  nevertheless,  there  seems 
to  be  a  wide  difference  of  opinion  in  the  use  of  the  terms  germicide, 
disinfectant,  and  antiseptic.  It  is  evident  that  these  three  cannot 
ha\e  a  synonymous  interpretation,  but  they  are  frequently  used  as 
meaning  death  to  bacteria.     Abbott^  defines  these  terms  as  follows: 

"An  antiseptic  is  a  body  which,  by  its  presence,  prevents  the  growth 
of  bacteria  without,  of  necessity,  killing  them;  a  body  may  be  anti- 
septic without  possessing  disinfecting  properties  to  any  very  high 
degree,  but  a  disinfectant  is  always  an  antiseptic  as  well. 

"A  germicide  is  a  body  possessing  the  property  of  killing  bacteria." 

The  possibility  of  injuring  instruments  has  deterred  dentists  from 
using  many  of  the  agents  recommended  for  the  purpose  of  sterilization. 

Miller'^  made  tests  of  various  agents  with  indifferent  results,  with 
the  exception  of  carbolic  acid,  trichlorphenol,  and  mercury  bichlorid. 
The  list  tested  included  the  following: 

Carbolic  acid  in  5  per  cent,  aqueous  solution  and  in  pure  form. 

Lysol  in  5  per  cent,  aqueous  solution. 

Trichlorphenol  in  5  per  cent,  acjueous  solution. 

Sul)limate  in  5  per  cent,  aqueous  solution;  also  in  the  strength  of 
1  to  1000  of  water. 

Benzoic  acid  in  the  strength  of  1  to  300  of  water. 

Potassium  permanganate  in  5  per  cent,  aqueous  solution. 

Resorcin  in  10  per  cent,  aqueous  solution. 

Hydrogen  peroxid    in  10  per  cent,  aqueous  solution. 

Saccharin  in  concentrated  alcoholic  and  acjueous  solution. 

^-naphthol  in  5  per  cent,  alcoholic  solution. 

Pyoktanin  in  concentrated  aqueous  solution. 

Absolute  alcohol. 

Antiseptin  in  5  per  cent,  aqueous  solution. 

Zinc  sulfate  in  concentrated  aqueous  solution. 

The  essential  oils  in  5  per  cent,  emulsions  and  in  pure  form. 

>  Dental  Cosmos,  July,  1S91.  2  The  Principles  of  Bacteriology.  1909. 

3  Dental  Cosmos,  July,   1891,  page  520. 


AGENTS    USED  FOli  STERILIZATION  129 

The  three  previously  named,  carbolic  acid,  trichlorphenol,  and  mer- 
cury bichlorid,  were  the  only  ones  that  gave  any  satisfactory  results, 
and  these  only  partially  so.  In  regard  to  the  rest,  Prof.  Miller  says: 
"They  all  fall  far  short  of  those  already  mentioned.  The  10  per  cent, 
solution  of  the  'peroxide  of  hydrogen  came  next  to  carbolic  acid,  but 
is  considerably  inferior  to  it.  The  essential  oils,  in  emulsions  as  well 
as  in  pure  form,  utterly  failed  to  produce  the  desired  action." 

The  results  obtained  by  Miller  are  not  wholly  in  accord  with  those 
of  some  others.  Charles  B.  Nancrede,  M.D.,  in  an  article'  gives  a 
list  of  agents  which  have  "proved  most  reliable  clinically,  can  be  resorted 
to  in  any  emergency,  or  are  peculiarly  applicable  to  meet  exceptional 
indications:" 

Marked  inhibition.  Complete  inhibition. 

Mercuric  chlorld 1  to  1,600,000  1  to  300,000 

Oil  of  mustard             1  to  333,000  1  to  33,000 

Thymol 1  to  86,000 

Oil  of  turpentine 1  to  75,000 

lodin 1  to  5,000  1  to  1,000 

Salicylic  acid 1  to  3,300  1  to  1,500 

Eucalyptol 1  to  2,500  1  to  1,251 

Borax 1  to  2,000  1  to  700 

Potassium  permanganate 1  to  1,400 

Boric  acid 1  to  1,250  1  to  800 

Carbolic  acid 1  to  1,250  1  to  850 

Quinin 1  to  830  1  to  625 

Alcohol 1  to  100  1  to  12.5 

At  the  time  these  tables  were  prepared  one  agent  not  mentioned  was 
practically  unknown  as  an  antiseptic — formaldehyd,  or  in  solution 
known  as  formalin. 

Dr.  Elmer  G.  Horton,  B.S.,  assistant  in  bacteriology,  Department 
of  Hygiene,  University  of  Pennsylvania,  undertook,  at  the  request  of 
Dr.  Edward  C.  Kirk,  a  series  of  investigations  with  formaldehyd,^  the 
results  of  which  are  given,  omitting  the  details  of  experiments. 

"We  employed  the  gas  generated  by  heating  over  an  alcohol  lamp 
a  pastil  which  contained  five  grains  of  paraform.  The  lamp  was  placed 
in  a  tin  box  of  nearly  one  cubic  foot  capacity  .  .  .  (Fig.  96).  Among 
the  instruments  employed  in  the  tests  were  various  chisels,  excavators, 
and  burs.  These  were  boiled,  shown  by  cultural  method  to  be  sterile, 
then  either  dipped  into  bouillon  cultures  or  infected  from  selected  cases 
found  in  the  operative  clinic  of  the  Department  of  Dentistry,  University 
of  Pennsylvania.  After  infection  each  instrument  was  placed  in  a  sterile 
tube  and  kept  at  incubator  temperature  (37.5°  C.)  for  three  hours  ,  .  . 
In  a  single  test  with  moist  instruments  we  found  sterilization  complete. 
After  the  infection  and  subsequent  drying  the  tubes  containing  the 
infected  instruments  were  separated  into  two  lots,  one  to  be  subjected  to 
the  method  of  disinfection  and  the  others  to  be  kept  as  controls,  by 

1  Treatment  of  Wounds:  Antisepsis  and  Asepsis,  Surgery  by  American  Authors,  Park,  page  365. 
'  Dental  Cosmos,  July,  1898. 
9 


130 


ANTISEPSIS  IN   DENTISTRY 


wliic-h  would  be  shown  that  no  step  other  than  the  action  of  formal- 
tlehvd  destroyed  the  vitaHty  of  tlie  ^ernis.  .  .  .  After  exactly  ten  or 
fifteen  minutes,  according  to  the  experiment,  the  door  was  opened  and 
theinstrument(|uickly  removed.  .  .  .  Each  instninient  (controls  like- 
wise) was  placed  in  a  considerable  amount  of  sterile  bouilhm  and  these 
cultures,  to<i;ether  with  the  subcultures  made  from  them,  observed  for 
at  least  one  week,  ...  In  all  experiments  a  free  growth  (levelo[)ed 
from  the  controls.  .  .  .  The  disinfection  of  instruments  purposely 
infected  in  the  clinics  from  cases  of  caries,  pyorrhea,  and  gingivitis  was 
satisfactorily  accomplished  in  every  case.  .  .  .  We  concluded  that 
infected  dental  instruments  can  be  disinfected  without  injury  in  a  closed 

Fig.  96 


Schering's  formiilin  sterilizer. 

space  of  less  than  one  cubic  foot,  by  an  exposure  of  fifteen  minutes  to  the 
formaldehyd  gas  generated  from  a  pastil  containing  five  grains  of  para- 
form  by  heating  the  pastil  over  a  proper  alcohol  lamp\" 

In  an  article  on  the  "Uses  and  Limitations  of  Formaldehyd  in 
Dentistry,"  by  Dr.  F.  W.  Low,  Buffalo,  N.  Y.,^  the  effect  of  formal- 
dehyd gas  is  further  given  as  shown  by  a  series  of  experiments  con- 
ducted by  Dr.  Thos.  B.  Carpenter,  assistant  bacteriologist  to  the  Health 
Department  of  the  City  of  Buffalo.  Without  entering  into  detail,  the 
experiments  consisted  of  two  series,  one  of  infected  instruments  and  the 
other  of  clothing  either  of  school  children,  of  nurses,  or  of  the  doctor 
in  the  presence  of  contagion,  to  determine  whether  they  could  be  thor- 
oughly sterilized  by  placing  them  over  night  in  a  wardrobe  exposed  to 
the  fumigation  of  the  lamp  used. 


I  Dental  Cosmos,  February,  1900. 


AGENTS  USED  FOR  STERILIZATION  131 

The  conclusion  of  Dr.  Carpenter  was  that  "This  apparatus  can  be 
rehed  upon,  after  an  exposure  of  from  ten  to  fifteen  minutes,  to  destroy 
thin  hiyers  of  the  eonnnon,  non-spt)ruhitlng  pathogenie  organisms." 

In  regard  to  the  second  series  of  experiments  with  clothing,  he  says: 
"It  is  evident,  therefore,  that  twelve  hours'  exposure  to  the  action  of 
this  lamp  in  a  eloset  15.8  cubic  feet  capacity  is  sufKcient  for  effective 
surface  disinfection,  the  most  resistant  pathogenic  bacteria  being  de- 
stroyed." 

A  third  series  of  experiments  was  undertaken  with  scaling  instru- 
ments taken  from  the  instrument  cases  from  several  operators,  including 
that  of  Dr.  Low.  The  result  of  this  elaborate  experimentation  is  thus 
summed  up  by  the  author:  "Every  set,  except  the  one  where  the  lehole 
case  was  fumigated  over  night,  produced  some  cultures;  but  not  one  set 
developed  a  culture  cf  pathogenic  organisms." 

"The  Low  lamp  consists  of  an  asbestos-lined  tray,  or  box,  supported 
on  legs  (Fig.  97,  A),  with  an  opening  in  the  bottom  to  admit  the  chimney 
of  the  lamp,  the  purpose  of  which  is  to  conduct  the  fumes  of  the  for- 
maldehyd  gas  into  the  tray  and  upon  the  instruments  it  is  desired  to 
sterilize. 

"The  working  parts  of  the  lamp  are  shown  in  the  illustration.  An 
ordinary  alcohol  wick  is  drawn  into  the  wick  tube.  To  place  the  lamp 
{B)  in  operation,  fill  it  with  ivood  alcohol,  grain  alcohol  being  incapable 
of  generating  formaldehyd.  Adjust  the  cone-shaped  platinum  coil  so 
that  it  just  touches  the  top  of  the  wick.  Light  the  latter;  place  on 
chimney,  and  after  a  few  seconds'  waiting  blow  out  the  flame.  If  the 
cone  be  in  proper  adjustment  to  the  wick,  it  will  be  observed  that  the 
coil  glows  like  a  live  coal,  but  there  is  no  flame  or  dangerous  heat. 

"Having  the  lamp  in  operation,  as  described,  and  the  tray  properly 
adjusted  to  set  over  it,  as  in  the  illustration,  instruments  may  be  placed 
in  the  tray  and  allowed  to  remain  for  ten  minutes,  a  sufficient  time  to 
eft'ect  sterilization.  When  taken  out  they  should  be  wiped  dry  with  a 
surgiealli/  clean  napkin  or  towel. 

"To  stop  the  fumigation  going  on  in  the  lamp,  remove  the  chimney 
and  slide  the  cage  high  up  on  the  tube,  so  that  the  platinum  cone  no 
longer  touches  the  wick,  then  allow  it  to  cool  before  replacing  chimney." 

While  it  is  not  difficult  for  the  average  dentist  to  use  formaldehyd 
as  a  disinfectant,  it  will  probably  be  considered  a  useless  expenditure 
of  time,  and,  therefore,  boiling  in  water  and  soda  for  at  least  twenty 
minutes  seems  the  more  feasible  and  is  equally  certain  in  the  results. 

The  dentist  who  aims  to  keep  only  aseptic  instruments  should  have 
two  sets  in  daily  use.  "\Mien  through  with  one  patient  the  instruments 
should  undergo  the  boiling  process  in  preparation  for  the  next.  At 
the  close  of  the  day  all  instruments  used  should  be  thoroughly  boiled 
and  dried  upon  aseptic  napkins  and  placed  in  the  case.  The  possibility 
of  infection  from  the  latter  must  not  be  overlooked.     The  first  and 


132 


ANTISEPSIS  IN    DENTISTRY 


second  set,  therefore,  used  the  next  day  for  the  first  time  should  be 
either  boiled  again  or  each  instrument  dipped  into  an  antiseptic  fiuid. 
For  this  purpose  the  writer  prefers  a  strong  sohition  of  hydronaphthol 
(S  grains  to  the  ounce  of  alcohol)  to  the  carbolic  acid  solution  ordinarily 
used.     With  this  care  all  danger  of  infection  can  be  removed  and  the 


Fi<;.  97 


Fig.  98 


dentist  relieved  of  all  legal  responsibility.  The  combination  sterilizer 
and  hot-water  heater  for  gas  or  alcohol,  designed  by  Dr.  George  J. 
Paynter,  seems  to  be  a  convenient  arrangement  for  the  office. 

Fig.  99  represents  a  very  convenient  and  efficient  sterilizer  where 
the  electrical  current  is  established.     It  sterilizes  with  boiling  water. 


AGENTS   USED  FOI{  STElil IJZATION 


133 


The  full  capacity  of  this  stcrili/cr  is  two  quarts.  It  has  rounded  corners 
and  all  seams  are  eliminated,  with  the  exception  of  one  at  the  terminal 
This  prevents  collection  of  debris,  and  facilitates  cleaning.     It 


en( 


is  provided  with  a  tray  for  small  instruments,  and  with  nickel-plated 
hooks  for  lifting  it.    The  lid  is  provided  with  a  wooden  knob. 

It  can  be  run  by  the  direct  or  alternating  current,  and  will  boil  water 
in  fifteen  minutes.  It  is  made  of  heavy  copper,  nickel  plated  outside 
and  tinned  inside.  The  equipment  includes  a  six  foot  connecting  cord, 
with  terminals  and  plug.  Its  efficiency,  simplicity,  and  ornamental 
character  recommends  it  for  the  dental  office  where  available.  It  is 
introduced  by  the  S.  S.  White  Dental  Manufacturing  Company. 


Fig.  99 


The  preparation  of  the  hands  previous  to  operations  is  most  per- 
plexing to  the  conscientious  operator,  whether  this  be  in  surgery  or 
dental  practice.  In  order  that  dental  operators  may  be  able  to  arrive 
at  definite  conclusions  in  regard  to  what  may  be  required  of  them  in 
their  daily  work,  the  following  quotation  is  given  from  Nancrede's 
article^  on  the  care  required  in  hospital  surgical  practice: 

"Sterilized  water  as  hot  as  can  be  borne  should  be  employed.  This 
must,  of  course,  be  never  cooled  by  the  addition  of  any  but  cold  ster- 
ilized water.  .  .  The  nail  brush,  best  made  of  vegetable  fiber,  must 
always  be  carefully  rinsed  after  use  and  sterilized  by  heat  for  each 
operation.  .  .  Although  it  is  alleged  that  all  soaps  made  by  heat  are 
sterile — indeed,  that  potash  soap  is  an  active  germ  inhibitor  in  the  pro- 
portion of  1  to  5000 — yet  it  is  the  part  of  prudence  to  combine  with  the 
soft  soap  5  per  cent,  of  hydronaphthol  or  thymol,  to  insure  that  the 
soap  itself  is  free  from  germs.  After  thoroughly  rubbing  into  the  hands 
and  arms  and  under  the  nails  abundance  of  soap,  the  nail  brush  and 


1  Loc.  cit. 


134  ANTISEPSIS  IN   DENTISTRY 

hot  water  must  be  vioorously  used,  espeeiall}'  beneath  and  arounil  tlie 
nails,  for  from  two  to  five  minutes.  Next,  carefully  clean  the  nails  and 
around  them  with  a  nail  cleaner.  Removal  of  all  grease  can  now  he 
eifected  by  ether  or  by  innnersion  in  alcohol,  or  best  l)y  alcohol  contain- 
ing 5  per  cent,  of  dilute  acetic  acid,  which  should  be  rinsed  oil"  thor- 
on<j^hlv  with  sterilized  water,  removing  the  last  traces  of  soap.  Finally, 
the  hands  should  be  immersed — not  merely  dij^ped — in  a  1  to  2000  mer- 
curic chloride  solution  foi*  not  less  than  three — preferably  five — minutes. 
Instead  of  corrosive  sublimate  solution,  ordinary  mustard  flour  mixed 
in  the  hands  into  a  thin  paste  with  sterilized  water,  used  with  gentle 
friction  for  two  or  three  minutes  and  then  removed  with  sterilized 
water,  will  pi'ove  a  most  successful  germicide." 

While  the  foregoing  may  serve  as  a  basis  for  comj)arison,  it  would 
be  wholly  impracticable  in  dental  practice.  It  n^nains,  however,  that 
the  hands  of  the  dental  operator  should  be  the  subject  of  constant  care. 
Nails  should  be  kept  short  and  scrupulously  clean. 

The  importance  of  this  to  the  dentist  cannot  be  overstated,  and  it 
is  probably  the  one  precaution  most  neglected.  The  fingers  are, 
necessarily,  continually  in  the  mouth  of  the  patient,  and  nothing  dis- 
turbs a  cleanly  person  more  than  ill-kept  nails,  possibly  loaded  with 
infectious  matter.  Nails  should  be  closely  cut  and  the  surrounding 
tissue  well  cared  for  by  brush  and  antiseptic  solutions. 

It  seems  to  the  writer  that  the  use  of  a  good  potash  soap  and  nail  brush, 
with  bathing  the  hands  in  alcohol,  will  be  amply  sufficient  unless  work- 
ing on  a  syphilitic  patient,  when  more  effective  methods  must  be  resorted 
to,  and  there  can  be  nothing  better  than  the  mode  described  l)y  Dr. 
Nancrede. 

The  conclusions  to  wdiich  the  writer  has  arrived  from  experience  and 
study  of  the  subject  may  be  summed  up  briefly  as  follows: 

1.  Dipping  instruments  in  an  antiseptic  fluid  previous  to  operating, 
while  beneficial,  is  not  sterilization. 

2.  That  boiling  in  w^ater  with  soda  added  is  for  the  dentist  the 
most  convenient  means  of  sterilizing  instruments  without  injury,  while 
the  more  recently  introduced  method  of  formaldehyd  antisepsis  is  a 
dry  process  that  does  not  rust  or  injure  steel  instruments  and  is  also 
promptly  effective.  The  acjueous  solution  of  formaldehyd  (formalin, 
3o  to  40  per  cent.)  is  probably  the  best  agent  where  simply  dipping 
the  instrument  is  desired.     Two  per  cent,  is  of  sufficient  strength. 

3.  That  the  ordinary  methods  used  to  eftect  sterilization  in  surgical 
practice  are  not  possible  in  dentistry,  but  that  every  dentist  is  legally 
and  morally  bound  to  live  as  near  to  the  rules  of  antisepsis  as  is  possible 
with  the  demands  of  a  daily  practice. 


CHAPTEE    IV 

EXAMINATION  OF  'VlIK  TEETH  AND  ORAL  CAVITY 
PRELIMINARY  TO  OPERATION— REM()\AE  OF  DE- 
POSITS—APPLIANCES AND  METHODS  — RECORDING 
RESULTS 


By  8.  H.  GUILFORD,  A.M.,  D.D.S.,  Ph.D. 

Before  undertaking  the  examination  of  the  teeth  it  ^^•ill  be  necessary 
to  remove  any  calcic  deposits  that  may  be  found  upon  the  various  tooth 
surfaces  in  order  that  every  portion  of  the  crowns  may  be  open  to 
inspection  and  instrumental  exploration. 

This  operation  is  usually  known  as  "scaling,"  from  the  fact  that  the 
deposits  are  generally  of  a  hard  consistency,  and  when  force  is  applied 
come  away  in  scaly,  fractured  portions. 

The  instruments  employed  are  denominated  scalers  and  are  furnished 
in  a  variety  of  forms.  Those  of  a  siclde  shape  have  met  with  the  greatest 
favor,  their  peculiar  form  enabling  the  operator  to  reach  conveniently 
more  portions  of  the  tooth  surface  than  would  be  possible  with  an 
uncurved  point. 

Fig.  100 


3  41  42  10 

Scaling  instruments. 

Some  of  these  are  shown  in  Fig.  100.  Frequently,  however,  a  large 
sized  hoe  or  a  spoon  excavator  will  be  found  to  operate  more  readily  and 
expeditiously  where  large  masses  of  the  deposit  are  to  be  removed,  as 
upon  the  lingual  surfaces  of  the  lower  incisors  and  the  buccal  surfaces 
of  the  upper  molars. 

In  the  removal  of  the  hard  deposits  from  the  teeth  great  care  should 
be  exercised  to  avoid  injury  to  the  soft  tissues  and  the  infliction  of  un- 
necessary pain. 

(135) 


i;^()       EXAMINATION  OF   THE  TEETH  AND  ORAL  CAVITY 

As  the  deposits  usually  tcnniiiatc  in  an  abrupt  uuirifiu  next  to  the 
gum,  the  edge  of  the  instrunuiit  cinpioycd  tor  removal  should  be  caught 
above  this  ledge  and  drawn  toward  the  o.eclusal  oi"  iueisal  surface  with 
some  force,  so  as  to  dislodge  as  large  a  portion  of  the  material  with  each 
movement  as  possible.  By  repeated  efforts  of  this  character  every  portion 
of  the  deposit  may  be  removed  without  tissue  injury  or  bloodletting. 

With  the  exercise  of  care  the  operation  of  scaling  need  not  be  painful, 
except  in  the  case  of  loosened  and  diseased  teeth,  and  even  then  the 
discomfort  may  be  greatly  lessened  by  steadying  with  the  thumb  and 
forefinger  of  the  left  hand  each  tooth  as  it  is  operated  upon. 

The  teeth  once  freed  from  deposits,  their  examination  should  be  pro- 
ceeded with.  The  importance  of  a  careful  and  thorough  examination 
can  scarcely  be  overestimated,  for  failure  to  discover  even  a  small 
lesion  might  result  in  subsequent  serious  consequences.  In  making 
the  examination,  certain  instruments  and  accessories  are  necessary  and 
should  be  at  hand. 


Fig.  101 


/^^ 


^)       (tt))     --     B 


Record  chart. 

Record  Charts. — Charts  consisting  of  a  diagram  of  the  teeth  may  be 
printed  upon  ordinary  pa})er  and  fastened  together  in  tablet  form,  or 
they  may  be  printed  upon  heavier  paper,  or  cardboard,  and  handled 
separately.  Charts  of  different  design  are  to  be  had,  but  the  one  shown 
in  Fig.  101,  designed  by  the  writer,  has  answered  every  purpose;  it 
represents  both  the  permanent  and  temporary  sets  of  teeth  and  each 
arch  in  its  natural  position.  This  enables  the  examiner  to  make  his 
record  more  cjuickly  and  easily. 

Exploring  Instruments. — These  are  delicate,  tapering  steel  points,  with 
spring  temper  and  bent  at  an  angle  near  the  point.  Those  designed 
by  Dr.  Perry  have  met  with  the  greatest  favor.  They  come  in  a 
number  of  forms,  fashioned  into  different  angles  and  curves,  as  shown 
in  Fig.  102. 


MACNIFYING  GLASS 


137 


The  explorers  arc  funiishecl  either  as  sohd  iiistniments  or  as  points  to 
be  screwed  into  a  cone-socket  handle,  the  latter  heinn;  preferred  hecause, 
when  broken,  they  may  be  easily  and  (juickly  replaced.  The  first  two 
shown  in  the  illustration  will  serve  all  ordinary  purposes,  but  the  others 
are  valuable  in  reaching  points  difficult  of  access. 


'r-\ 


Fig.  102 


fnl 


Wi 


13 


14  15      17 

Exploring   instruments. 


Mouth  Mirrors. — These  may  be  had  either  with  a  plain  surface,  wdiich 
reflects  the  image  in  its  natural  size,  or  a  concave  surface,  in  which  the 
image  is  magnified.  Some  prefer  one  form,  some  the  other,  but  the 
majority  of  practitioners  favor  the  use  of  the  concave  glass,  since  with 
tlie  enlargement  of  the  image  w-e  have  also  the  magnifying  of  the  defect, 
which  enables  it  to  be  more  quickly  detected. 

Fig.  103 


Jeweller's  eye-glass. 


Magnifjdng  Glass. — To  obtain  a  still  further  enlargement  of  the  object, 
many  operators  use  a  magnifying  glass  of  some  form  in  addition  to  the 
mouth  mirror.  One  known  as  the  jeweller's  eye-glass,  shown  in  Fig. 
103,  is  probably  the  simplest  and  the  most  convenient  form  for  dental 
examination.  In  use  it  is  held  between  the  thumb  and  forefinger  of  the 
left  hand,  about  four  inches  from  the  object,  and  by  its  magnification 
surfaces  of  the  teeth  may  be  examined  very  quickly  and  accurately. 
Frequently  the  mouth  mirror,  held  in  the  right  hand  and  placed  under- 


138        EXAMINATION  OF   TIII'J   TEETH   AND  ORAL  CAVITY 

neath  the  tootli  to  be  examined,  throws  a  htfht  upon  the  surtaee  in  such 
a  way  as  to  illumine  it,  and  with  the  eye-glass  on  the  opposite  side,  the 
illumination  and  enlargement  are  com])lete.  By  the  combined  use  of 
the  two  glasses,  cavities  or  partly  disintegrated  enamel  are  discovered 
which  would  have  been  missed  by  the  ordinary  means  of  examination. 

Silk  Floss.— Silk  floss  is  a  very  important  accessory,  as  it  enables  us  to 
detect  any  lesion  or  roughness  on  the  approximal  surface  which  has  not 
otherwise  been  discovered.  The  silk  should  not  be  waxed,  for  if  unwaxed 
the  fraying  of  its  fibers  when  passed  between  the  teeth  serves  to  indicate 
any  unnatural  condition  of  the  surface.  If  waxed,  no  fraying  would  be 
likely  to  occur,  the  wax  serving  as  a  lubricant.  The  strands  should 
not  be  too  light  nor  yet  too  heavy;  an  intermediate  grade  being  the  best. 

Air  Syringe. — An  air  syringe  is  a  valuable  adjunct  in  removing  moisture 
from  any  surface  of  the  tooth  or  between  the  teeth,  thus  enabling  us  to 
examine  the  parts  more  thoroughly. 

Absorbent  Paper. — Thin  Japanese  absorbent  paper  or  absorbent 
cotton,  together  with  delicate  tweezers  to  assist  in  applying  it  to  different 
surfaces  for  the  purpose  of  removing  moisture,  should  also  be  provided. 
With  all  these  accessories  at  hand,  the  examination  may  be  begun.  The 
patient  should  be  placed  comfortably  in  the  chair  and  the  clothing  pro- 
tected by  a  towel  or  a  large  napkin  fastened  around  the  neck.  A  glass 
of  water  should  be  provided  and  additional  hand  napkins  placed  upon 
the  bracket  table  for  the  patient's  use. 

Technique. — The  positions  where  caries  is  most  likely  to  be  found  are 
in  the  fissures  and  sulci,  and  upon  the  approximal  surfaces,  the  latter 
requiring  the  greatest  care  in  examination  on  account  of  their  difficulty 
of  access.  In  beginning  the  examination  a  general  inspection  of  the 
mouth  and  teeth  should  be  made  with  the  mouth  mirror,  and  the  visible 
cavities  and  defects  marked  upon  the  chart  with  a  pencil.  The  explorer 
should  next  be  passed  over  every  exposed  surface  carefully  and  also 
under  the  free  margin  of  the  gum.  Occasionally  cavities  are  found 
hidden  under  the  gingival  margin  which  would  not  be  discovered  unless 
revealed  by  the  explorer.  In  examining  the  approximal  surfaces  they 
should  be  made  as  dry  as  possible  with  absorbent  paper  or  cotton, 
followed  by  a  blast  from  the  air  syringe  thoroughly  to  dry  the  surface. 
The  explorer  should  be  introduced  into  the  interproximal  space  witli 
its  point  directed  toward  the  occlusal  surface;  then,  by  passing  it  back 
and  forth,  every  portion  of  the  approximal  surface  may  be  examined, 
excepting  the  contact  point.  This  should  V)e  followed  by  silk  ffoss, 
passing  it  back  and  forth  between  the  points  of  contact.  Even  after 
the  use  of  the  explorer  and  the  silk  it  is  well  to  inspect  these  surfaces 
with  a  jeweller's  glass,  for,  while  there  may  be  no  extensive  disintegration 
of  the  enamel,  there  may  be  an  altered  condition  of  the  surface,  as 
evidenced  by  discoloration  or  a  chalky  appearance  near  to  or  at  the 
point  of  contact,  which  will  be  revealed  by  the  use  of  the  jeweller's  glass 


TKCIIMQCE  l:-}9 

above  aiul  reHectinii;  mirror  helow.  In  order  that  tlie  examination  may 
be  orderly  and  nothin<i;  omitted,  it  is  well  to  follow  a  definite  j)lan. 

We  may  begin  the  examination  at  the  median  line  of  the  upper  areh, 
examinino-  eaeh  tooth  successively  back  to  and  includintf  the  third  molar; 
then,  by  beginning  again  at  the  median  line  and  passing  around  the  other 
side  in  the  same  manner,  we  will  have  included  all  the  teeth  of  the  uj)per 
arch.  The  lower  arch  should  then  be  examined  similarly.  As  cavities 
or  defects  are  found  they  should  be  marked  upon  the  chart,  and  it  is 
well  even  to  note  any  disposition  toward  tooth  disintegration  that  may 
be  met  with  in  the  course  of  the  examination.  The  electric  mouth  mirror 
has  been  recommended  as  an  aid  in  examination,  but  it  does  not  seem  to 
be  a  necessary  adjunct.  It  has  its  use  in  determining  whether  the 
pulp  in  a  tooth  is  alive  or  not,  but  the  mirrors  previously  mentioned 
are  sufficient  for  the  purpose  of  detecting  any  injury  to  tooth  substance. 

In  addition  to  marking  upon  the  chart  such  new  cavities  as  may  be 
found,  we  should  examine  the  condition  of  any  fillings  previously  inserted 
and  note  whether  or  not  they  are  fit  to  remain.  If  these  are  defective 
the  fact  should  be  noted  upon  the  chart,  and  if  in  the  course  of  the 
examination  places  are  found  where  it  cannot  be  definitely  decided 
whether  tooth  substance  has  been  injured  or  not,  it  should  be  noted 
for  further  examination.  In  addition  to  marking  upon  the  chart  the 
cavities  found,  it  is  well  to  indicate  upon  the  figure  of  the  tooth  the 
apparent  extent  of  the  tooth  injury;  in  other  words,  the  pencil  mark 
should  indicate  the  relative  size  of  the  cavity. 

If  it  is  desired  to  indicate  at  the  same  time  the  character  of  the  filling 
material  to  be  used  in  the  various  cavities,  it  may  be  done  by  the  use  of 
colored  pencils,  using  a  difterent  color  for  each  kind  of  material  to  be 
employed.  The  advantages  of  a  chart  record  are  various.  It  shows  at 
a  glance  the  extent  and  character  of  the  services  needed;  it  forms  the 
basis  for  the  estimating  of  time  required  or  expense  involved;  by  checking 
of?  each  item  as  completed  it  will  indicate  the  still  unperformed  opera- 
tions, and  permit  the  selection  at  each  sitting  of  such  work  as  is  fitted 
to  the  time  set  apart;  in  addition,  it  will  be  of  service  in  showing  to  the 
patient  the  number  and  character  of  the  proposed  operations. 

If  in  course  of  the  examination  it  is  apparent  that  the  patient  has  not 
been  in  the  habit  of  giving  proper  attention  to  his  teeth,  a  good  oppor- 
tunity is  aft'orded  for  instructing  him  in  the  matter,  and  impressing  upon 
him  the  fact  that  if  the  proposed  operations  are  to  be  lasting  and  efficient, 
it  is  quite  important  that  personal  care  on  his  part  shall  contribute  to  the 
desired  success. 


CHAPTER    V 

CREATINE  INTERDENTAL  SPACES  PREPARATORY  TO 
FILLINCJ;  (iRADUAL  SEPARATION;  IMMEDIATE  OR 
FORCIBLE  SEPARATION 

By  S.  H.  GUILFORD,  A.M.,  D.D.S.,  Ph.D. 

In  separating  teeth  to  obtain  space  for  operation  npon  their 
approximal  surfaces,  great  care  should  be  exercised  to  avoid  injury 
to  tlie  soft  tissues  or  undue  irritation  of  the  pericementum.  The  opera- 
tion at  best  is  one  which  patients  dread,  on  account  of  the  soreness 
induced  in  the  moving  teeth.  The  teeth  of  children,  either  deciduous 
or  permanent,  are  more  easily  and  quickly  separated,  owing  to  the 
greater  thickness  of  the  pericementum  and  imperfect  calcification  of 
the  alveolar  septa,  while  the  teeth  of  adults  move  more  slowly  and 
require  greater  time  for  their  separation  because  of  the  lessened  thick- 
ness of  the  pericementum  and  the  greater  density  of  the  septa. 
In  view  of  these  facts  the  character  of  the  force  to  be  applied 
and  the  means  of  applying  it  must  be  suited  to  existing  conditions. 
When  wedging  is  very  gradual  it  is  accompanied  by  little  irritation, 
and  conseciuently  the  soreness  is  reduced  to  the  minimum.  Where  it  is 
more  rapid  the  operation  is  attended  with  greater  irritation  and  more 
pain.  Various  substances  and  methods  may  be  employed  to  create 
interdental  spaces;  fibrous  substances  such  as  cotton,  tape,  wood,  etc., 
operate  by  the  absorption  of  moisture  and  consequent  expansion; 
elastic  rubber  exerts  resilient  force  and  operates  rapidly;  mechanical 
separation  by  steel  separators,  while  limited  in  its  results,  is  direct  in 
its  operation  and  often  very  useful  as  an  accessory  method. 

Gradual  Separation. — Cotton. — Cotton  for  separation  can  be  used  to 
the  best  advantage  when  a  wisp  of  it  is  twisted  and  drawn  between  the 
teeth  at  their  points  of  contact.  It  should  be  kept  dry  while  being 
inserted,  and  when  in  place  clipped  close  on  the  labial  and  lingual 
surfaces  of  the  teeth;  as  its  expansive  properties  are  largely  due  to  the 
absorption  of  moisture  and  are  limited,  it  should  be  renewed  each 
day  until  sufficient  space  is  gained.  The  fibers  may  be  constricted  and 
expansion  consequently  increased  by  passing  a  silk  ligature  through  the 
interdental  space  between  the  cotton  and  gum  and  around  the  pledget, 
then  drawing  it  tight  and  tying  in  a  knot — this  tying  of  the  cotton  also 
serves  to  keep  it  in  place  more  securely.  A  modification  of  this  plan 
consists  in  wrapping  or  twisting  the  wisp  of  cotton  around  a  silk  liga- 
(140) 


GRA  D  UA  L  SEP  A  UA  TION 


14] 


tiire.  After  it  has  heen  drawn  hetweon  the  teeth  the  free  ends  of  the 
ligature  are  passed  around  the  mass  as  in  tlie  previous  instance,  and  tied. 
Linen  Tape. —  This  substance  operates  on  the  same  principle  as 
cotton,  and  is  more  convenient  to  iiandle  and  place  in  position.  The  tape 
should  be  thin  and  very  little  more  than  one-eighth  of  an  inch  in  width; 
one  thickness  should  be  drawn  between  the  teeth  the  first  day,  two  on  the 
second,  tTiree  on  the  third,  and  so  on  until  sufficient  space  has  been 
gained.  Some  operators  employ  waxed  tape  for  separating,  but  the 
unwaxed  is  preferable  because  it  absorbs  moisture  rapidly  and  it  is 
the  expansion  of  the  fiber  from  absorption  of  moisture  that  gives  it  its 
efficiency.  As  the  tape  is  easy  to  grasp  and  manipulate,  patients  fre- 
quently can  insert  the  subsequent  thicknesses  themselves  after  the  first 
piece  has  been  placed  by  the  operator.  \Miile  both  of  the  foregoing 
methods  of  separation  are  slow,  requiring  four  or  five  days  to  produce 
the  desired  result,  they  are  almost  painless  on  account  of  their  slowness. 

Fig.  104  ■ 


Wood  wedges. 


Wood. — Compressed  hickory  in  the  form  commonly  known  as  pivot- 
wood,  or  some  softer  wood,  as  bass-wood  strips,  can  be  used  for  wedging. 
The  latter,  in  order  to  have  its  efficiency  increased,  should  be  cut  into 
strips  lengthwise  and  then  compressed  laterally  by  being  passed  between 
the  rolls  of  a  rolling  mill.  In  introducing  wood  of  any  kind  it  should  be 
whittled  to  a  wedge  (Fig.  104)  and  pressed  firmly  between  the  teeth  to 
be  separated.  When  in  place  and  the  protruding  portions  have  been 
clipped  oft'  with  a  wedge  cutter,  the  rough  ends  should  be  smoothed  with 
a  small  corundum  wheel  in  order  to  avoid  possible  irritation  of  the  lips 
or  tongue.  Like  cotton  or  linen  tape,  the  wood  expands  by  the  absorption 
of  moisture,  and  as  it  has  been  compressed  before  introduction,  its 
expansion  is  not  only  greater  but  more  rapid. 

Ccyrk. — On  account  of  its  compressibility  and  rapid  expansion  in  the 
presence  of  moisture,  cork  is  an  admirable  substance  for  the  separation 
of  teeth.  The  tenacity  w^th  which  it  clings  to  the  tooth  surface  is  another 
advantage  which  it  possesses,  because  it  is  less  likely  to  become  displaced 
than  wood.    Thin  slices  of  good  bottle  cork  may  be  used,  and  after  being 


142  CREATISa  INTERDENTAL  SPACES 

introduced  between  the  teeth,  should  he  chpped  (•h).se  with  a  siiurp 
bistoury.  As  cork  is  lacking  in  strength  it  cannot  l)e  forced  between 
teeth  that  are  cU:).se  togetlier.  A  shght  space  nnist  first  be  created  by 
the  use  of  some  other  material,  and  then  the  separation  contiimed  by 
pieces  of  cork  of  varied  thicknesses.  Although  its  operation  is  slow, 
cork  is  one  of  the  least  impleasant  substances  to  use  so  far  as  the 
patient's  comfort  is  concerned. 

Elastic  Rubber. — This  substance  operates  more  (juickly  in  sej)arating 
teeth  than  any  other  material  used  for  gradual  sej)aration.  Its  resiliency 
is  so  great  that  when  a  strip  of  it  is  drawn  between  the  teeth  its  effort  to 
return  to  its  original  form  causes  it  to  operate  incessantly  until  this  is 
accomplished.  Owing  to  its  constant  expansion,  the  teeth  under  its 
influence  are  rapidly  moved  apart,  and  as  a  result,  irritation  is  often  set 
up  in  the  pericementum,  accompanied  by  soreness  of  the  teeth  when 
touched.  Because  of  its  rapid  action  it  is  employed  far  more  fre(juently 
than  any  other  substance  for  the  separation  of  teeth,  and  as  the  irritation 
brought  about  by  its  use  is  its  only  objectionable  quality,  this  may  be 
modified  by  beginning  the  separation  with  a  very  thin  piece.  If  the 
teeth  to  be  separated  are  in  close  contact,  a  narrow  strip  of  medium 
rubber  dam  may  be  tlrawn  between  them  to  start  the  separation;  after 
this  has  lieen  in  place  for  a  day  it  can  be  followed  by  a  somewhat  thicker 
piece  which  may  be  allowed  to  remain  for  two  or  three  days. 

A  very  convenient  form  of  rubl)er  is  that  known  as  French  rubber 
tubing.  It  comes  in  various  sizes,  the  thickness  increasing  with  the 
diameter.  Sections  cut  from  the  tubing  and  then  slitted  afford  a  very 
convenient  means  for  introduction  between  the  teeth. 

According  to  the  writer's  experience,  the  use  of  elastic  ruljber  should 
be  confined  to  the  first  stages  of  separation,  to  be  followed  by  the  use 
of  cork  or  tape;  in  this  way  teeth  may  be  separated  with  very  little 
resulting  soreness.  As  rubber  is  extremely  slippery  when  moist,  it  is  very 
liable  to  change  its  position  in  the  act  of  separating,  and  to  slip  up  and 
impinge  upon  the  soft  gum  tissue  of  the  interdental  space;  it  has  been 
known  to  bury  itself  under  this  tissue  and  create  great  irritation  when 
the  patient  has  remained  away  from  observation  too  long.  To  avoid 
this  possibility,  when  rubber  is  placed  betw-een  the  teeth  it  should 
never  be  allowed  to  touch  the  gum,  and  at  the  same  time  should  not  be 
clipped  too  close  to  the  incisal  or  occlusal  surface. 

The  same  caution  should  be  exercised  in  the  placing  of  any  separating 
material  between  the  teeth.  Whatever  substance  is  employed,  we  should 
endeavor  to  retain  it  in  its  proper  position  by  any  and  every  means 
at  our  command.  At  the  same  time  the  patient  should  be  instructed  to 
return  at  once  to  the  office  if  it  be  found  that  the  substance  lietween  the 
teeth  has  become  loose  or  has  shifted  its  position.  Should  the  teeth 
show  symptoms  of  extreme  soreness  after  separation  by  any  method, 
it  may  be  relieved  before  operating  upon  them  by  placing  some  non- 


IMMEDIATE  Oli   FORVIBLE  SEPARATION 


143 


resilient  substance  like  o-utta-pereha  between  them  and  allowinjr  it  to 
remain  for  a  few  days.  In  this  way  the  space  will  be  preserved  and 
the  teeth  given  time  to  recover  from  their  tenderness. 

Base-plate  Gidta-pcrcha. — Where  large  approximal  cavities  exist,  and 
it  becomes  necessary  to  separate  the  teeth  in  order  that  their  normal 
contour  may  be  restored  by  filling,  a  very  excellent  method  is  to  pack 
the  cavities  a  little  more  than  full  with  red  or  white  base-plate  gutta- 
percha. By  the  action  of  the  opposing  teeth  in  closing,  the  material 
will  be  forced  farther  between  the  teeth  and  thus  separate  them  gradually 
and  almost  painlessly.  This  idea  originated  with  the  late  Dr.  W.  G.  A. 
Bonwill,  who  found  it  of  the  greatest  value  and  claimed  that  in  addition 
to  separating  the  teeth,  gutta-percha  would  force  the  gum  tissue  beyond 
the  gingival  margin  and  thus  expose  that  portion  of  the  cavity  which 
is  usually  difficult  of  access. 


Fig.   105 


Fig.  107 


Perry  separators. 


Capwell's  "  single-bow"  separator. 


Immediate  or  Forcible  Separation. — ^The  earliest  method  of  producing 
immediate  separation  consisted  in  driving  wooden  wedges  alternately 
between  the  teeth  at  their  points  of  contact  and  througli  the  interdental 
space  near  the  gingival  margin.  It  was  a  crude  and  painful  method, 
and  later  was  superseded  by  steel  separators  acting  upon  the  screw 
principle.  One  of  the  first  of  this  type  to  be  devised  was  the  "double- 
bow"  separator  invented  by  Dr.  S.  G.  Perry.  It  is  shown  both  separately 
in  Fig.  105  and  in  position  in  Fig.  106.  The  first  one  of  the  Perry 
separators  was  intended  for  use  between  the  incisors,  but  as  soon  as  its 
value  began  to  be  recognized,  others  of  the  same  form  were  devised  for 


144  CREATING  INTERDENTAL  SPACES 

use  hetween  the  side  and  posterior  teeth;  tinis  a  set  of  six  was  j)hiee(l  uj)on 
the  market  which  seem  to  meet  all  requirements  of  an  instrument  of  this 
character.  The  Perry  sej)arator  probably  is  used  today  more  than  any 
other  mechanical  separator  ever  devised.  Another  form  of  separator, 
shown  in  Fig.  107,  and  known  as  the  "single-bow,"  was  devised  by  Dr. 
G.  C.  Capwell.  While  it  may  be  used  between  any  of  the  teeth,  it  is 
more  especially  serviceable  in  the  anterior  part  of  the  mouth.  As  will  be 
noticed,  it  is  extremely  simple  in  construction,  and  when  in  position  is  well 
out  of  the  way  of  the  operator.  The  handle  used  to  operate  the  screw 
is  removable,  which  is  a  feature  peculiar  to  this  instrument. 

While  the  mechanical  separator  is  sometimes  regarded  as  a  painful 
instrument  on  account  of  its  rapidity  of  action,  it  really  need  not  be  a 
source  of  distress  to  the  patient  if  the  operation  is  not  hurried.  With 
one  or  two  turns  of  the  operating  screw  follow^ed  by  a  rest  of  a  few 
minutes  and  this  process  repeated,  a  fair  amount  of  space  can  be  obtained 
in  from  five  to  ten  minutes'  time.  It  will  not  usually  provide  as  great  a 
space  as  that  obtained  by  the  slower  methods,  but  a  plan  frequently 
followed  is  to  do  part  of  the  separating  by  the  slow  method  of  expansion 
and  then  at  the  time  of  the  operation  gain  a  little  more  space  by  the  use 
of  the  mechanical  separator.  It  has  also  been  observed  that  if  the  teeth 
should  retain  some  of  their  soreness  after  gradual  separation,  the  appli- 
cation of  the  mechanical  separator  and  its  tightening  will  immediately 
relieve  such  soreness  and  permit  the  operation  to  be  performed  painlessly. 

This  is  doubtless  due  to  the  paralyzing  of  the  nerve  fibers  of  the 
pericementum  under  the  pressure  developed  by  the  rapid  action  of  the 
screw.  The  mechanical  separator  can  be  used  to  great  advantage  in 
the  separation  of  children's  teeth  since  the  greater  thickness  of  the 
pericementum  permits  its  more  rapid  compression. 


CHAPTER    VI 

MODIFICATION  OF  DENTINAL  SENSITIVITY  BY  DE- 
HYDRATION; TOPICAL  MEDICATION;  ELECTRICAL 
OSMOSIS;  GENERAL  ANESTHESIA 

By  8.  H.  GUILFORD,  A.M.,  D.D.S.,  Ph.D. 

As  all  normal  dentin  is  sensitive,  the  term  sensitive  dentin  is  incorrect 
when  used  to  designate  hypersensitive  dentin,  which  may  be  defined 
as  an  exaltation  of  the  normal  sensitiveness  of  dentin.  The  dentin 
which  comprises  the  large  bulk  of  the  hard  tissues  of  a  tooth  is  covered 
by  enamel  on  the  crown  and  cementum  on  the  root;  therefore,  in  the 
condition  of  normality  the  only  indication  we  have  of  the  sensitiveness 
of  dentin  is  that  which  we  experience  in  the  application  of  substances, 
usually  food,  either  considerably  above  or  below  the  normal  temperature 
of  the  mouth.  If,  however,  the  enamel  has  been  removed  from  a  tooth 
in  whole  or  in  part,  either  by  accident,  mechanically,  or  by  caries,  the 
dentin  is  exposed  and  thus  sensitiveness  becomes  immediately  apparent. 
Normal  dentin  may  become  exposed  to  outside  influence  through 
erosion,  abrasion,  traumatism,  or  caries.  When  exposed  by  erosion  or 
abrasion  it  may  or  may  not  be  hypersensitive.  Very  often  hyper- 
sensitiveness  is  observed  in  teeth  where  the  enamel  has  been  worn  away 
from  the  point  of  the  cusps  or  where,  through  gum  recession,  the  cemen- 
tum has  become  exposed  and  gradually  removed  by  friction.  When 
enamel  has  been  abraded,  as  by  a  clasp  on  a  plate,  its  wearing  through 
to  the  dentin  is  so  gradual  that  when  the  latter  becomes  exposed  it  is 
not  apt  to  be  very  sensitive;  in  this  case  the  pulp,  stimulated  to  new" 
activity  by  the  external  irritation,  has  formed  new  dentin  upon  the 
pulpal  wall  to  compensate  for  that  worn  away  externally  by  attrition, 
which  accounts  for  the  lessened  sensitivity.  When  a  tooth  has  been 
invaded  by  caries  there  may  be  no  actual  exposure  of  the  dentin  to  the 
air  and  other  external  influences,  since  the  soft  products  of  caries  overlie 
and  protect  it,  thus  serving  as  a  non-conductor.  In  the  process  of 
excavating  a  cavity,  when  the  debris  of  caries  is  removed,  actual  dentinal 
exposure  takes  place  and  the  cutting  of  the  dentin  in  the  continued 
excavation  of  the  cavity  is  often  found  to  be  very  painful.  In  such 
cases  the  dentinal  fibrillse  may  have  been  exposed  to  the  action  of  caries- 
producing  influences,  generally  lactic  acid,  and  become  irritated  thereby. 
This  is  especially  true  when  the  progress  of  caries  has  been  rapid;  when 
It  is  slower  the  pulp  has  opportunity  to  protect  itself  from  irritating 
10  '  (145) 


14(i  MODIFICATION  OF  DENTINAL  SENSITIVITY 

influences  hy  the  formation  of  secondary  dentin  on  the  wall  of  the  pulp 
chaniher  opj)osite  the  point  of  irritation.  In  carious  cavities  the  dentin 
is  usually  most  sensitive  at  the  junction  of  the  enamel  and  dentin,  while 
the  layer  of  dentin  immediately  beneath  the  carious  mass  is  more  sensitive 
than  that  l)eyond  it.  In  some  cases  even  large  cavities  may  be  excavated 
with  almost  no  pain,  whereas  in  others  of  apparently  similar  character  the 
slightest  touch  of  the  instrument  will  cause  almost  unbearable  pain. 
So-called  hard  or  dense  teeth  are  less  sensitive  than  others,  owing  to 
the  lesser  amount  of  protoplasmic  matter  in  the  tubuli. 


TREATMENT 

Remedies  may  be  arranged  in  two  classes.  In  the  first  are  those 
that  benumb  or  anesthetize  the  fibrillar  in  the  tubuli,  and  in  the  second, 
those  that  chemically  destroy  the  fibrillse  to  a  certain  depth. 

Remedies  that  Benumb. — Dehydration. — As  moisture  is  necessary 
to  enal)le  nerve  filaments  to  convey  sensation  to  the  nerve  centres, 
absence  of  moisture  will  necessarily  interfere  with  or  prevent  such 
transmission;  therefore  the  simplest  and  most  logical  method  of 
producing  analgesia,  in  whole  or  in  part,  in  a  tooth  cavity  for 
the  purpose  of  excavating,  is  to  dispel  the  moisture  from  the  walls 
of  the  cavity  and  from  the  tubuli  which  form  such  surfaces.  It  has 
been  found  that  desiccation  of  a  cavity  either  by  ordinary  exposure  to 
the  air  for  a  length  of  time,  or  by  subjecting  it  to  a  current  of  warm 
air  will  bring  about  a  condition  of  immunity  to  sensation  in  propor- 
tion as  such  desiccation  is  thorough  or  partial.  To  best  accomplish 
desiccation  of  the  dentin,  the  rubber  dam  should  be  adjusted  to  the 
teeth  and  the  greater  portion  of  the  carious  mass  carefully  removed 
with  spoon  excavators;  the  cavity  should  be  bathed  with  absolute 
alcohol,  and  then  subjected  to  a  stream  of  warm  air  applied  in  some 
convenient  manner.  The  ordinary  air  syringe  or  chip  blower  may  have 
its  point  heated  in  a  flame,  and  then  by  forcing  the  air  in  the  bulb 
slowly  through  the  tube,  a  jet  of  w^arm  air  wnll  be  delivered  in  the  cavity. 
By  holding  the  nozzle  of  the  syringe  at  the  proper  distance,  and  having 
learned  by  experience  how  much  heat  to  apply,  one  can  often  inject  a 
current  of  air  into  the  cavity  at  nearly  the  same  temperature  as  that  of 
the  tooth;  but  if  the  air,  when  it  reaches  the  cavity,  should  be  either 
perceptibly  above  or  below  the  proper  temperature,  pain  will  be  pro- 
duced. In  some  warm-air  syringes  the  tube  is  provided  with  a  hollow 
receptacle  somewhere  along  its  length,  which,  when  heated,  raises  the 
temperature  of  the  air  within  it  before  being  directed  into  the  tooth 
cavity.  Neither  of  these  methods  is  at  all  exact,  and  they  are  therefore 
liable  to  produce  more  or  less  pain  in  the  act  of  dehydration.  A  better 
plan  is  to  employ  9.  syringe  in  which  a  coil  of  fine  platinum  wire  is 


T  HE  ATM  EN  T 


147 


contained  within  the  orifice;  this  coil  is  connected  by  wires  throufijh 
the  body  of  the  syringe  with  a  source  of  electric  current;  in  operation 
the  resistance  encountered  by  the  current  of  electricity  passing  through 
the  platinum  coil  heats  it  and  maintains  a  steady  temperature.  Air 
forced  over  this  coil  and  through  the  nozzle,  especially  air  supplied  from 
a  receiver  and  under  pressure  that  can  be  controlled,  may  be  heated  to 
a  temperature  that  will  approximate  very  closely  that  of  the  tooth,  and 
therefore  produce  little  or  no  pain.  If  the  air  passing  from  the  nozzle 
of  the  syringe  should  be  too  warm,  it  can  be  modified  by  holding  it  a 
little  farther  away  from  the  tooth,  or  if  not  warm  enough,  more  heat  will 
be  delivered  when  it  is  held  in  closer  proximity. 

Fig.  108 


Electric  warm-air  syringe. 


Fig.  108  represents  an  instrument  of  this  character  with  a  compressible 
bulb  instead  of  an  air  supply  from  a  receiver.  The  operation  of  desicca- 
tion should  not  be  hurried;  time  must  be  allow^ed  for  raising  the  air  to  a 
suitable  temperature,  so  as  to  cause  as  little  pain  as  possible.  In  addition, 
the  operation  should  be  continued  until  the  dentinal  walls  of  the  cavity 
have  become  perceptibly  lighter  in  color,  indicating  that  they  have  been 
robbed  of  their  moisture.  If  desiccation  is  not  carried  to  this  point 
it  will  fail  in  its  effectiveness;  but  if  the  moisture  has  been  removed 
from  the  dentin  to  a  considerable  depth,  as  it  may  be  if  desiccation  be 
sufiBciently  continued,  sensitiveness  W'ill  have  become  nearly  or  entirely 
obliterated.  Whether  we  depend  entirely  upon  dryness  to  relieve  the 
hypersensitivity  or  not,  it  should  always  be  resorted  to,  for  it  proves  a 
most  valuable  preliminary  where  it  is  to  be  followed  by  medication  of 
any  kind. 

Another  means  of  avoiding  excessive  pain  in  excavating  is  by  the  use 
of  sharp  instruments  and  burs.  It  is  well  known  that  a  sharp  instrument 
wall  sever  sensitive  tissue  with  less  pain  than  a  dull  one,  and  this  is  equally 
true  in  the  cutting  of  a  substance  like  dentin,  which  contains  a  consider- 
able amount  of  organic  matter.  Burs  cause  pain  in  operating  principally 
through  dulness  or  through  being  held  in  contact  with  the  ca\dty  wall 
too  continuously.     They  should  not  only  be  sharp,  but  run  at  high 


148  MODIFICATION   OF   DENTINAL  SENSITIVITY 

speed  and  allowed  to  touch  the  .surface  very  li^litly  as  they  revolve; 
this  avoids  the  heat  of  friction  and  conse(juently  lessens  pain. 

Topical  Medication.  Kefrio;eration  by  a  spray  of  ether  or  ethyl  chlorid 
will  reduce  the  temperature  of  the  sensitive  tissue  and  benumb  it,  but 
this  is  a  painful  method  and  consequently  not  often  resorted  to.  A 
constant  stream  of  warm  water  slightly  above  the  temperatiu'e  of  the 
blood,  directed  into  the  cavity  during  the  operation  of  excavation  has 
been  found  in  many  cases  greatly  to  lessen  the  normal  sensitivity  of  the 
part;  but  as  it  is  inconvenient  to  use  and  very  difficult  for  one  to  oju'rate 
in  the  presence  of  this  stream  of  liquitl,  the  method  has  not  been  gener- 
ally adopted.  Vapocain,  a  proprietary  remedy  consisting  of  a  15  per 
cent,  solution  of  cocain  in  ether,  found  some  favor  a  few  years  ago  for 
reducing  the  hypersensitiveness  of  dentin  previous  to  excavating,  but  as 
it  was  not  efficient  in  a  large  number  of  cases  it  soon  fell  into  disfavor. 
Cocain  hydrochloric!  in  a  10  per  cent,  to  25  per  cent.  a(|ueous  solution 
forced  into  the  tubules  sometimes  produces  a  mollifying  etVect,  but  it  is 
difficult  to  retain  the  licjuid  and  apply  pressure  except  in  cavities  of 
limited  size  and  favorable  form. 

The  late  Prof.  W.  1).  Miller  claimed  good  results  from  the  following 
method:  After  removing  the  bulk  of  debris  from  a  cavity,  he  packed  a 
mass  of  vulcanizable  rubl)er  into  it  to  take  its  form.  Removing  this  and 
drying  the  cavity  he  placed  within  it  a  small  portion  of  cotton,  saturated 
with  a  10  per  cent,  solution  of  cocain  hydrochlorid.  Replacing  the  mass 
of  rubber  in  the  cavity,  he  exerted  pressure  upon  it  in  such  manner  as 
to  force  the  solution  into  the  tubuli  and  produce  desensitization.  By 
repeating  the  treatment  at  intervals  during  excavation,  he  was  able  to 
prepare  very  sensitive  cavities  with  very  little  pain. 

Electrical  Osmosis. — Another  method  of  employing  cocain  is  by  having 
it  carried  into  the  substance  of  the  dentin  by  means  of  electrical  osmosis. 
This  process,  known  as  cataphoresis,  consists  in  placing  a  solution  of 
cocain  on  cotton  in  the  sensitive  cavity,  and  having  it  carried  along  the 
dentinal  tubuli  toward  the  pulp  by  means  of  a  galvanic  current.  A 
battery  is  employed  with  the  negative  electrode  inserted  in  the  cavity, 
and  the  anotle  placed  upon  some  part  of  the  patient's  body,  as  the  hand 
or  cheek.  The  current  carries  the  cocain  into  the  deeper  j)ortions  of  the 
tooth  and  anesthetizes  it.  While  in  this  condition,  which  usually  lasts 
for  an  hour  or  more,  the  tooth  may  be  worked  u|>on  without  any  pain. 
For  a  wiiile  this  method  met  with  great  favor  because  of  the  perfect 
results  obtained,  but  later  it  was  foimd  to  be  a  very  slow  method,  often 
consuming  more  time  than  the  operator  had  at  his  command,  and 
occasionally  requiring  a  second  application  in  order  to  produce  complete 
anesthesia  of  the  tooth;  in  addition,  the  cocain  in  some  cases  penetrated 
to  the  pulp  itself  and  devitalization  followed. 

Cocain  Analgesia. — A  better  method  of  using  cocain  for  anesthetiza- 
tion consists  in  forcing  a  weak  solution  of  it  into  the  dentin  of  a  tooth 


COCAIN  ANALGESIA 


149 


by  means  of  a  powerful  coinpoiiiul  pressure  syringe.  Several  instru- 
ments of  this  character  are  on  the  market,  but  that  known  as  the  Weaver 
is  probably  one  of  the  most  efficient.    It  is  shown  in  Fig.  109. 


Fig.  109 


In  use  a  small  pit  is  drilled  through  the  enamel  to  the  dentin  with  a 
No.  ^  bur,  the  nozzle  of  the  syringe  being  tapered  to  fit  the  pit  accurately. 
After  the  barrel  of  the  syringe  has  been  charged  with  a  5  to  15  per  cent, 
solution  of  cocain  in  water,  the  point  is  forced  tightly  into  the  pit  in  the 
tooth,  and  pressure  brought  to  bear  upon  the  plunger  of  the  syringe. 
If  the  fit  between  the  drill-pit  and  the  nozzle  point  is  accurate,  and  the 
pressure  in  the  syringe  is  kept  up  for  one  or  two  minutes,  it  will  be  found 
that  the  dentin  has  become  entirely  anesthetized  and  can  be  operated 
upon  without  pain.  As  this  method  is  much  simpler  than  that  of  cata- 
phoresis,  it  has  met  with  great  favor.  Some  practitioners  have  hesitated 
to  adopt  the  use  of  the  syringe  for  fear  of  the  anesthetization  being 
carried  so  far  as  to  result  in  pulp  devitalization.  There  is,  of  course, 
this  possibility  if  the  pressure  be  continued  too  long,  and  also  in  cases 
where  the  resistance  of  the  teeth  to  such  pressure  is  less  than  normal, 
but  those  who  have  adopted  the  method  and  have  become  familiar 
through  experience  with  the  conditions  that  favor  its  employment  are 
very  loud  in  its  praise.  This  method  of  injecting  cocain  is  also  fre- 
quently employed  to  desensitize  dentin  in  the  gradual  approach  to  the 
pulp  for  its  devitalization.  Secondary  dentin  is  difficult  to  penetrate  on 
account  of  its  greater  density;  sometimes  several  applications  being 
required  before  anesthetization  is  accomplished.  Still  another  method 
of  relieving  hypersensitivity  of  the  dentin  consists  in  injecting  a  1  per 
cent,  solution  of  cocain  into  the  gum  tissue  overUing  the  apex  of  the 
root.  This  acts  by  paralyzing  the  sensory  nerve  leading  from  the  pulp. 
Some  practitioners  claim  very  satisfactory  results  from  its  use. 


150 


MODIFICATION  OF  DENTINAL  SENSITIVITY 


General  Anesthesia. — 'I'liis  radical  uiethotl  of  treatment,  while  very 
sekloin  ealled  for,  is  of  the  very  greatest  vahie  in  cases  where  the 
hypersensitivity  of  cavities  is  so  extreme  as  not  to  permit  of  the  least 
progress  in  excavation,  and  where  the  nervous  condition  of  the  patient 
does  not  warrant  the  infliction  of  any  pain  whatsoever.  In  the  inthu-e- 
nient  of  this  condition,  some  of  the  general  anesthetics  may  l)e  employed; 
several  are  serviceable,  and  the  choice  rests  with  the  operator.  Somno- 
form,  a  proprietary  compound,  consisting  of  ethyl-  and  methyl-chlorid 
and  ethyl-bromid,  has  w'on  favor  in  dental  and  surgical  practice,  and 
has  been  found  to  be  reasonably  safe  in  its  anesthetic  action.  Chloro- 
form has  been  used  on  account  of  its  rapid  action  and  the  freedom  from 
nausea,  but  its  unfavorable  action  on  the  heart  in  some  cases  should 
prohibit  its  use  in  dental  practice.  In  the  employment  of  ether  only 
sufficient  of  the  drug  should  be  inhaled  to  induce  partial  or  peripheral 
anesthesia.  Frecjuently,  while  there  is  absence  of  sensation,  conscious- 
ness is  still  present. 


Fig.  110 


Fig.  110  represents  a  simple  appliance  for  convenient  administration. 
It  is  a  metal  tube  about  one  inch  in  diameter,  with  a  convex  termination 
at  one  end  having  a  central  opening  about  three-sixteenths  of  an  inch 
in  diameter.  Into  the  other  end  is  fitted  a  cap  with  an  extension  for 
holding  in  the  hand.  In  use,  the  tube  is  loosely  filled  with  cotton,  upon 
which  a  (juantity  of  the  anesthetic  is  poured.  After  the  cap  is  replaced 
the  appliance  is  given  to  the  patient  with  instructions  to  hold  it  to  the 
nose  and  inhale.  ^Yhen  the  hand  drops  it  is  evident  that  muscular 
relaxation  and  partial  anesthesia  have  been  produced,  and  excavation 
can  be  proceeded  with.  When  sensation  returns  the  patient  will 
have  to  repeat  the  inhaling  to  again  produce  anesthesia,  when  further 
operations  may  be  resumed.  By  this  mild  administration  the  patient 
is  absolutely  relieved  of  all  pain  without  any  unpleasant  effects.  In 
this  as  in  all  other  cases  where  insensibility  is  produced  the  operator 
must  proceed  with  great  caution,  otherwise  the  pulp  may  be  reached 
and  injured  without  warning.  The  writer  has  had  several  cases  in 
which  he  could  accomplish  nothing  by  the  usual  methods  of  desensiti- 
zation,  but  which  were  rendered  amenable  to  treatment  by  partial 
general  anesthesia.  In  ordinary  practice  it  will  be  found  that  thorough 
desiccation  under  the  rubber  dam  with  sharp  instruments  delicately 
handled,  and  an  occasional  application  of  carbolic  acid,  will  usually 


TREATMENT  151 

mitigate  or  relieve  most  of  tlie  pain  in  nine-tenths  of  all  cases  presenting; 
for  the  balance,  where  sensitivity  is  unusual,  the  high-pressure  syringe 
and  cocain  will  be  found  most  effective. 

Remedies  which  Chemically  Destroy  the  Fibrils  to  a  Limited 
Depth,  Preventing  Transmission  of  Sensation,  are  the  Common 
Cauterants. — Those  principally  used  for  this  purpose  are  zinc  chlorid, 
silver  nitrate,  carbolic  acid,  and  the  latter  combined  with  potassium 
hydroxid.  To  cause  coagulation  or  destruction  of  the  tubular  content, 
their  efficiency  depends  upon  the  length  of  time  they  are  applied,  and 
all  of  them  cause  more  or  less  pain. 

Zinc  Chlorid  is  more  irritating  than  the  others,  but  by  adding  crystals 
of  cocain  to  the  zinc  chlorid  at  the  time  of  its  application  this  effect 
may  be  modified.  In  deep-seated  cavities  it  should  not  be  employed  on 
account  of  the  danger  of  pulp  irritation  either  at  the  time  of  application 
or  subsequently. 

Carbolic  Acid.^ — ^^fhis  drug  may  be  applied  in  full  strength  to  cavities 
of  any  depth  without  danger.  It  operates  quickly  but  not  to  any  great 
depth,  and  is  the  most  generally  used  of  all  obtundents.  Whenever  used 
for  desensitization  the  cavities  should  be  dried  as  thoroughly  as  possible 
before  application,  for  in  this  way  the  acid  is  not  diluted  to  so  great  an 
extent  by  the  water  in  the  tubuli.  Cavities  sensitive  to  air  after  excava- 
tion are  immediately  relieved  by  the  application  of  carbolic  acid.  It  not 
only  serves  to  counteract  thermal  shock  after  filling,  but  gives  to  the  tooth 
a  warm  and  comfortable  feeling.  For  this  reason  many  operators,  as 
a  precautionary  measure,  wipe  all  cavities  with  carbolic  acid  before 
filling.  Another  virtue  possessed  by  carbolic  acid  is  that  of  a  sterilizer 
of  dentin. 

Silver  Nitrate. — This  salt  is  slow  in  action  and  does  not  operate  to  a 
great  depth;  it  cauterizes  the  contents  of  the  tubuli  and  gives  them  a 
protective  coating.  It  is  useful  on  denuded  dentin  at  the  necks  of 
teeth  or  exposed  surfaces  on  the  tooth  crown.  The  discoloration  pro- 
duced by  its  use  is  objectionable,  but  on  all  exposed  dentin  surfaces 
where  it  is  not  visible  it  is  an  admirable  desensitizer. 

Robinson's  Remedy. — ^This  preparation  is  composed  of  equal  parts  of 
caustic  potash  (potassium  hydroxid)  and  carbolic  acid;  it  is  sometimes 
useful  in  relieving  sensitiveness  in  cavities,  though  it  is  generally  preferred 
for  application,  like  silver  nitrate,  to  denuded  surfaces,  and  operates  by 
destroying  the  tubular  contents.  Some  operators  occasionally  depend 
upon  time  and  the  presence  of  a  filling  to  mitigate  hypersensitiveness. 

Temporary  fillings,  the  various  zinc  cements  or  non-conducting 
gutta-percha,  will  frequently  produce  a  marked  effect  in  this  respect. 
After  partial  excavation  and  filling  with  some  temporary  material,  it 
has  been  found  that  the  tooth  becomes  less  sensitive  to  thermal  influences, 
and  that  after  the  temporary  filling  has  remained  in  a  cavity  for  several 
months,  excavation  may  be  resumed  and  carried  forward  with  com- 


152  MODIFICATION  OF  DENTINAL  SENSITIVITY 

parative  comfort.  The  chanjjjr  in  sensitiveness  of  a  cavity  brought 
about  by  the  presence  of  a  non-conductive  filling  was  formerly  attributed 
to  a  process  of  eburnation  or  solidification  of  the  tul)ular  structure,  but 
more  recent  investigations  indicate  that  it  is  due  to  a  deposition  of 
secondary  dentin  on  the  walls  of  the  pulp  chamber,  thus  increasing  the 
mass  of  dentin  through  which  sensation  has  to  be  conveyed.  Tsually, 
hy{)ersensitive  dentin  needs  to  be  treated  at  the  time  of  its  discovery 
during  excavation  .so  that  the  operation  may  not  be  needlessly  delayed. 


CHAPTER    VII 

TECHNIQUE  OF  CAVITY  PREPARATION 

By  THOMAS  E.  WEEKS,  D.D.S. 

In  the  light  of  our  present  knowledge  we  must  consider  all  cavities  as 
the  result  of  some  pathological  condition.  We  cannot  consider  a  carious 
tooth  as  an  individual  apart  from  its  fellows  and  its  environment,  or  the 
cavity  simply  as  a  hole  to  be  filled.  We  must  study  the  mouth  and 
teeth  as  a  whole  and  endeavor  to  determine  what  abnormal  or  patho- 
logical conditions  are  responsible  for  the  beginning  of  any  particular 
cavity. 

We  know  that  caries  is  the  result  of  the  breeding,  growth,  and  life 
activities  of  certain  microorganisms,  that  these  microorganisms  must 
be  sheltered  and  protected,  else  they  are  destroyed  or  their  action 
inhibited  by  nature's  weapons  against  disease  which  are  present  in 
every  mouth. 

We  know  that  well-formed  teeth,  arranged  in  proper  relation  to  their 
fellows,  both  as  regards  contact  and  occlusion,  in  mouths  which  are 
maintained  in  a  clean,  healthy  condition,  seldom  decay. 

Assuming  that  the  student's  knowledge  of  dental  anatomy  is  sufficient 
to  enable  him  to  recognize  normal  conditions,  the  following  several 
points  should  be  noted:  (1)  Form  of  the  teeth;  (2)  their  arrangement 
in  the  arch ;  (3)  their  proximal  contact ;  (4)  the  interproximal  spaces  and 
embrasures;  (5)  occlusion;  (6)  the  health  of  the  gums,  and  especially 
the  condition  of  that  portion  which  should  fill  the  interproximal 
spaces. 

Without  a  knowledge  of  what  is  normal  we  cannot  recognize  the 
abnormal.  Unless  we  can  determine  how  much  we  can  improve  existing 
conditions  by  our  completed  operation,  the  preparation  of  any  given 
cavity  will  not  be  performed  with  that  intelligence  necessary  to  insure 
the  best  results. 

A  perfect,  well-formed  tooth  is  one  in  which  there  are  no  structural 
imperfections  which  result  in  pits  and  fissures,  having  such  form  that 
when  in  position  in  the  arch  it  will  make  perfect  contact  with  its  fellows 
(similarly  well  formed),  i.  e.,  a  small  contact  point  in  the  incisal  or 
occlusal  third  in  both  labio-lingual  and  gingivo-occlusal  aspects.  If 
this  form  prevails,  the  result  must  be  well-formed  interproximal  spaces, 

(153) 


154 


TECHNIQUE  OF  CAVITY  PREPARATION 


with  sufficient  septum  of  alveolar  tissue  to  support  and  nourish  enough 
healthy  gum  tissue  to  properly  fill  the  space.  With  such  form  we  will 
have  broad  embrasures,  which  will  insure  the  cleansing  of  all  of  that 
portion  of  the  proximal  surfaces  not  covered  and  protected  by  the  gum 
septum  in  the  movement  of  the  food  as  it  is  forced  rootward  in  the  act 
of  mastication.  When  we  consider  the  cases  on  record  where  all  of  the 
teeth  have  been  forced  into  improper  occlusion  by  the  imperfect  occlusal 
form  of  one  filling,  the  importance  of  the  occlusion  is  apparent.  When 
we  have  reached  this  point  in  our  diagnosis  it  will  usually  be  apparent 
that  much  of  the  unhealthy  condition  of  the  soft  tissues,  if  any  exist,  is 
due  to  some  of  the  faulty  conditions  in  form  already  noted.  When  this 
is  corrected  and  normal  spaces  restored,  the  tissues  will  resume  a  healthy 
appearance.  If  due  to  other  causes,  it  is  usually  amenable  to  treatment 
detailed  in  another  chapter. 

In  order  that  the  text  may  be  intelligible  we  must  understand  the 
language  of  its  descriptions.  The  nomenclature  employed  is  that 
adopted  by  the  National  Institute  of  Dental  Pedagogics,  which  is  based 
upon  the  suggestions  of  Dr.  Black,  and  applies  only  to  prepared  cavities : 


REPORT  OF  COMMITTEE  NATIONAL  ASSOCIATION  OF  DENTAL  PEDAGOGICS. 
CAVITY  NOMENCLATURE 


All  that  is  to  be  said  in  describing  cavity  preparation  can  be  expressed  by  the  use 
of  the  following  nouns  and  adjectives: 


Cavity, 
Wall, 
Margin, 
Plane, 


Surface, 
Angle, 
Thirds, 
Emljrasure, 


Labial, 
Buccal, 
Lingual, 
Proximal, 


Mesial, 
Distal, 
Incisal, 
Occlusal, 


Gingival, 
Axial, 
Pulpal, 
tSubpulpal. 


CAVITY    NAMES 


Cavities  in  the  teeth  take  the  names  of  th^  surfaces  in  which  they  occur. 


Cavity  ' 


Simple 


Complex 


Labial, 
Buccal, 
Lingual, 
Mesial, 
Distal, 
Occlusal. 
Mesio-incisal, 
Disto-incisal, 
Mesio-lal)ial, 
Disto-labial, 
Mesio-lingual, 
I  )isto-lingual 
Mesio-occlueal, 
Disto-occlusal, 
Linguo-occlusal, 
Bucco-occlusal, 
Mesio-distal-occlusal, 
(( )ther  combinations 
by  the  same  rule.) 


TECHNIQUE  OF  CAVITY  PREPARATION 


155 


WALL  NAMES 


L;il)i;il. 
Jlucciil, 
Incisal, 
( )cclusal, 
ljii<:;iial, 
Wall  i    Mesial, 
])i.stal, 
CJingival, 
v\xial, 
Pulpal, 
Subpulpal. 

Rule,    cavity  walls  take    the   names   of    the    surfaces   of   the  tooth  which  they 
appi'oach. 


That  wall  of  a  cavity  in  an  axial  surface  of  a  tooth  that 
covers  the  pulp  is  called  the  (i.ri<iL  wall.  If  the  cavity  is  ex- 
tended to  include  the  pulp  chamber  tliis  wall  takes  the  name 
of  the  wall  of  the  pulp  chamber.  'J'iie  l)ottom  or  floor  of 
occlusal  caviti(\s  is  called  the  pulpal  wall.  If  extended  to 
include  the  pulp  chamber  it  becomes  tlie  subpulpul  wall. 


Angles 


Line  (Axial) 


Angles  (Simple  Cavities) 


Mesio-buccal, 
Mesio-lingual, 
Disto-buccal, 
Disto-lingual. 


Point 


Line  (Pulpal) 


Bucco-axial, 
Lin^uo-axial, 
Mesio-axial, 
Disto-axial, 

Bucco-pulpal, 
Linguo-pulpal, 
Mesio-pulpal, 
Disto-pulpal. 

Bucco-gingival, 

Linguo-gingival, 

Mesio-gingival, 

Disto-gingival, 

Axio-gingival, 

(and  combinations  with 

occlusal  wall). 

Mesio-buccal-pulpal, 
Disto-bucco-pulpal. 


Occlusal 

Cavities. 


Axial  Surface 
Cavities. 


Occlusal  Cavities. 


Axial  Surface 
Cavities. 


Mesio-linguo-pulpal, 
Disto-lingual-pulpal. 


Point  Angles  (the  union  of  three  line  angles)  take  their  names  from  the  surfaces 
forming  them.     In  occlusal  cavities  there  are  four. 

In  complex  cavities  on  axial  surfaces  there  is  another  horizontal  line-angle,  i.  e.,  in 
axial  cavities  combined  with  occlusal,  the  one  formed  by  union  of  the  axial  and  the 
pulpal  wall — axio-pulpal. 

Division  into  Thirds 

Cavities  may  be  divided  into  thirds,  for  convenience  in  description,  as  teeth  are 
divided. 


Names  op  Margins 


Mesial, 
Distal, 
Buccal, 
Labial, 
Lingual, 
Incisal, 
Occlusal, 
.  Gingival. 


Margins  ■ 


156 


TECHNIQUE' OF  CAVITY  PREPARATION 


Nomenclature  of  Simple  Cavities 


Occlusal  Cavities 

Mesial, 

Distal. 

Walls        .      .  i  Buccal. 

Linujual, 

.  I'uliKil. 

f  Mesio-huccal, 
Line  Angles      I  Mosio-lingual, 
(Longitudinal)   ]   Disto-buccal, 
Disto-lingual. 


Line  .\ngles 

(Transverse) 


Cavo-surface 
Angles' 


Point  Angles 


M1\RGIXS 


f  Mesio-pulpal, 
J  Disto-pulpal, 
I  Linguo-pulpal, 
I  Bucco-pulpal. 

r  Mesio-occlusal, 
J  Disto-occlusal, 
I  Buceo-occlusal, 
I  Lingiio-occliisal. 

[  Mesio-biicco-piilpal, 
Disto-bucco-pulpal, 
Mesio-linguo-piilpal 

I  Disto-lingiio-piilpal. 

[  Mesial, 
I  Distal, 
I  Buccal, 
I  Lingual. 


Labial,  Buccal,  or  Lingual  Cavities 

Mesial, 
Distal, 
Walls  .  -I  Gingival, 

<  )cclu.sal  or  Incisal, 
Axial. 


Line  Angles     j  Mesio-axial, 

(Longitudinal)        I,  Disto-axial. 


Mesio-occlusal, 

Disto-occlusal, 

Mesio-gingival, 

Disto-gingival, 

Occluso-axial, 

Oingivo-axial. 

Based  on  the  .same 
rule  a.s  for  occlusal 
cavities. 

Mesio-axio-gingival, 

Disto-axio-gingival, 

Mesio-axio  occlusal, 

I  Disto-axio-occlusal, 

Mesial, 
Distal, 
Gingival, 
.  Occlusal  or  Incisal. 


Line  Angles 

(Transverse) 


Cavo-surface 
Angles' 


Point  Angles 


Margins 


Simple  cavities  on  proximal  surfaces  have  the  same  number  of  walls,  angles,  and 
margins  as  those  on  other  axial  surfaces,  and  are  named  similarly. 

With  this  basis  all  cavities,  however  complex,  may  be  easily  named  and  described. 

Cavity  Classification,  Nomenclature,  and  Preparation 
Classificatinti 


Cavities 


Pit  and  Fissure. 
(No  extension  for 
prevention) 


Cavities  in   the   lingual  surfaces  of    upper 

incisors. 
Cavities  in  occlusal  surfaces  of  bicuspids  and 

molars. 
Cavities  in  the  occlusal  two-thirds  of    the 

buccal  and  lingual  surfaces  of  molars. 


Smooth  Surface 

(Extension  for 

prevention) 


Cavities  in  the  gingival  third  of  the  labial, 
buccal,  and  lingual  surfaces. 

Cavities  in  proximal  surfaces  of  incisors  and 
cuspids  which  do  not  involve  the  mesial 
or  distal  incisal  angle. 

Cavities  in  proximal  surfaces  of  incisors  and 
cuspids  which  do  involve  the  mesial  or 
distal  incisal  angle. 

Cavities  in  the  proximal  surfaces  of  bicus- 
pids and  molars. 

Note. — Cavities  occurring  in  consequence  of  arrested  development  are  not  in- 
cluded. 

This  report  was  adopted  by  the  Institute. 

'  Cavo-surface  angle — An  angle  formed  by  a  wall  of  a  cavity  and  the  surface  of  the  tooth  in 
which  the  cavity  is  situated. 


INSTRUMENTS 


157 


PREPARATION 


In  cavity  preparation  there  are  four  definite  steps: 

1.  Establi.sliing  outline  of  the  cavity. 

2.  Removing  softened  dentin  (decay). 

3.  Giving  the  cavity  proper  shape, 
retention  form,  and  convenience  form. 

4 


This  iiickides  resistance  form, 


Bevelling  and  smoothing  the  enamel  wall. 


INSTRUMENTS 

The  instruments  used  in  cavity  preparation  are  hand  instruments — 
those  held  in  and  manipulated  by  the  hand;  and  engine  instruments 
— those  held  in  a  hand-piece  and  revolved  by  power.  The  power  instru- 
ments or  burs  have  the  same  advantage  over  hand  instruments  that  the 
power  planer  has  over  the  hand  planer,  but  owing  to  the  peculiar  con- 
struction of  the  teeth,  especially  the  enamel,  there  are  many  parts  of  the 
operation  which  may  be  more  effectively  and  speedily  performed  with 


115        116        117 


20 

16 

65       3 

20 

20 

20 

9 

Darby- 

9 

9 

6 

Perry, 

12 

12 

2 

L 

R 

12 

hand  instruments.  The  hand  instruments  used  are  chisels  and  exca- 
vators. Chisels  are  straight  (Fig.  HI),  oblique  (Fig.  112)  (this  form 
is  made  in  pairs,  right  and  left),  or  double  oblique  (Fig.  113),  and 
those  in  which  the  blade  is  at  an  angle  with  the  axis  of  the  shaft  (Fig. 
114).  Excavators  are  divided  into  three  classes,  according  to  the  form  or 
position  of  the  blade:  hatchets,  hoes,  and  spoons,  or  discoids.  Hatchet 
excavators  are  those  in  which  the  hatchet-shaped  blade  is  at  an  angle 
with  the  axis  of  the  shaft,  with  its  edge  in  the  plane  of  the  angle  (Fig. 
115).  Hoe  excavators  are  those  in  which  the  hoe-shaped  blade  is  at  an 
angle  with  the  shaft,  with  its  edge  at  right  angles  with  the  plane  of  the 
angle  (Fig.  116). 


158  TECHNIQUE  OF  CAVITY  PREPARATION 

Spoons  arc  eitlicr  contra-aii^fle  hoes,  with  a  rounded  cuttirif^  t'di^^e,  for 
direct  cutting,  or  contra-angle  rights  and  lefts,  for  side  cutting  (Figs. 
117  and  US). 

Discoids  have  a  disk-shaped  blade  with  a  cutting  edge  around  the 
whole  periphery  except  where  it  is  attached  to  the  shank  (Fig.  119). 
As  the  point  to  be  operated  upon  is  so  frefjuently  inaccessible  to  direct 
force,  the  necessity  arises  ioT  obli(jue  chisels  or  those  which,  like  exca- 
vators, have  the  blade  at  an  angle  with  the  shaft.  If  the  j)()int  to  be 
operated  upon  can  be  a{)proached  so  the  force  can  be  delivered  in  a 
straight  line  from  the  hand  or  mallet  to  the  point  to  be  cut,  the  handle, 
shank,  and  blade  may  have  a  common  axis  (Fig.  120  h).  If  the  point 
to  be  operated  upon  is  not  accessible  to  direct  force,  i.  c,  when  the  force 

Fig.  120 


must  be  delivered  from  a  point  somewhere  between  6  and  d  (Fig.  120), 
w^e  must  employ  chisels  of  the  oblique  type  or  those  with  the  l)lade  at  an 
angle  with  the  shaft,  or  excavators.  In  instruments  having  angles,  the 
angle  between  the  shaft  and  blade  is  greater  or  less  as  the  point  of 
approach  is  far  from  or  near  to  the  line  h  (Fig.  120). 

Angles  and  curves  between  blades  and  shafts  and  in  shanks  are  for 
the  purpose  of  bringing  the  blade  into  direct  action  upon  surfaces  which 
are  inaccessible  to  straight  instruments. 

These  angles  are  expressed  in  centigrades  (Black),  divisions  of  the 
circle  into  100  equal  parts;  each  part  is  called  a  centigrade  (Fig.  121). 
If  the  shaft  of  an  excavator  is  laid  upon  a  line  passing  vertically  through 
the  centre  of  the  circle,  with  the  angle  between  the  blade  and  shaft  at 
the  centre  of  the  circle,  the  line  which  passes  through  the  centre  of  the 
blade  will  indicate  the  degree  of  the  angle  in  centigrades  (Fig.  122). 

Excavators  in  common  use  have  an  angle  somewhere  between  6  and 
28  centigrades.     It  has  also  b^en  found  that  those  most  universally  used 


INSTRUMENTS 


159 


are  those  luivin<ij  angles  6,  12,  and  23.  These  differences  in  angles 
divide  all  forms  of  excavators  int(^  three  groups.  The  next  point  of 
difference  between  excavators  is  the  variation  in  width  and  length  of 
blades.  The  width  may  be  expressed  in  tenths  of  a  millimeter  and  the 
length  in  millimeters.  Observation  also  shows  that  those  most  used 
have  blades  0.12,  0.8,  and  0.0  mm.  wide,  and  5,  3,  and  2  mm.  long. 


Fig.  121 


Fig.  122 


270 


270 


180 


Understanding  these  measurements,  the  dentist  can  accurately  express 
in  figures  the  width  of  blade,  the  length  of  blade,  and  the  angle  between 
the  blade  and  the  shaft  so  that  any  instrument  maker  can  make  the 
instrument  desired  from  a  formula.  In  writing  a  formula,  the  first 
figure  expresses  the  width  of  the  blade;  the  second,  the  length  of  the 
blade;  and  the  third,  the  angle  between  the  blade  and  the  shaft  (devia- 
tion from  the  axis  of  the  shaft  in  centigrades).  Arranging  the  hatchet 
and  hoe  excavators  most  widely  used  into  three  groups,  the  formulae 
appear  as  follows: 


12 

8 

6 

12 

8       6 

12        S 

5 

3 

2 

5 

3       2 

5       3 

6 

6 

6 

12 

12     12 
Fig.  123- 

23     23 
-Hatchets. 

6,  width  of  blade. 
2,  length  of  blade. 
23     23     23,  angle  in  centigrades. 


1 


? 

8 

6 

12 

8 

6 

12 

8 

6 

5 

3 

2 

5 

5 

2 

5 

3 

2 

§ 

6 

g 

12 

12 

12 

23 

23 

23 

IGO 


TECHNIQUE  OF  CAVITY  PREPARATION 


Fig.  124 — Hoes. 


12 

8 

6 

12 

8 

G 

12 

8 

6 

5 

3 

2 

5 

3 

2 

5 

3 

2 

6 

6 

C 

12 

12 

12 

23 

23 

23 

There  are  two  other  hatchets  which  are  ahnost  indispensable  in 
shaping  the  retention  angle  in  the  incisal  third  of  proximal  cavities  in 
incisors  and  cuspids;  these  have  an  acute  angle  between  the  blade  and 
the  shaft.     Their  formula  is  as  follows: 


5      3 
3      2 

28     28 — 2  instruments. 

Fig.  125 


When  the  blade  of  an  excavator  is  more  than  3  mm.  long  and  the 
angle  is  12  centigrades  or  more,  there  should  be  two  angles,  one  contra 
to  the  other  (contra-angled).  The  rule  for  contra-angling  is  that  the 
angles  be  so  formed  that  the  edge  of  the  blade  is  in  line  Avith  the  central 
axis  of  the  shaft,  or  when  the  handle  is  laid  on  a  plane  surface  the  edge 
of  the  blade  will  just  touch  the  surface.  In  spoon  excavators  there  are 
two  types,  the  contra-angle  spoon,  or  modified  hoe,  in  three  sizes, 
expressed  by  the  following  formulae: 

10    20    30 
3       4       5 
12     12     12--^3  instrnments. 


INSTRUMENTS 


161 


Fio.  126 


The  other  type  is  the  contra-aiigle 
double  plane,  side-cutting  rights  and 
lefts: 

20    15    10 
9      8      6 
12     12     12—6  instruments. 

Fig.  127 


Chisels. — Chisels  may  be  divided 
into  two  groups — straight  and  bin- 
angle  (contra-angle).  Three  in  each 
group  will  be  found  sufficient.  The 
blades  in  both  groups  measure : 

20     15  and  10  wide 
9       8  and     6  long. — 6  instruments. 


Fig.  128 


Fig.  129 


20 

15 

10 

20 

15 

10 

9 

8 

6 

9 

8 

6 

6 

6 

6 

The    binangles   have   an   angle    of 
6  centigrades. 
Another  form  of  contra-angle  chisels,  is  the  enamel  hatchet.     They 
are  called  hatchets  because  the  width  of  the  blade  is  in  the  plane  of 
the  angles,  but  they  are  chisels   because    the  blade  is  of   the   chisel 
form. 
11 


162 


TECHNIQUE  OF  CAVITY  PREI'AUATION 


They  are  rights  and   lefts,  and  are  used  as  side-ciittiii<i;  instniinents. 
Three  pairs  will  be  found  useful,  the  formula  for  which  is  as  follows: 

2U    15    10 
9       8       6 

12     12     12. — 6  instruments. 


Fig.  130 


Fig.  131 


20 

20 

1.5 

15 

10 

10 

9 

9 

8 

8 

6 

6 

12 

12 

12 

12 

12 

12 

L 

R 

L 

R 

L 

R 

Two  other  forms  of  chisels  which  have  not  been  reduced  to  formula  are 
those  known  by  Catalogue  Numbers  47, 48,  and  48  S  (Fig.  131).  Those 
instruments  known  as  gingival  margin  trimmers  are  also  chisels.  They 
are  contra-angled  double  plane  side-cutting  instruments.  As  the  edge 
of  the  blade  is  at  an  oblique  angle  with  the  long  axis  of  the  blade,  it  is 
necessary  to  use  another  figure  to  designate  this.  This  figure,  which 
indicates  the  angle  of  the  edge  with  the  axis  of  the  blade,  is  placed  l^etween 
the  first  and  second  figures.  There  are  two  groups  of  these  instruments 
formed  by  the  diflference  in  the  width  of  the  blades,  and  the  angle  between 
the  edge  and  the  axis  of  the  blade.     Their  formula  is  as  follows: 

20  20  15  15,  width. 

95  80  95  80,  angle  of  edge. 

19  9  9  9,  lengths. 

12  12  18  12,  angle. — 8  instruments. 

Fig.  132 


20 

20 

20 

20 

15 

15 

15 

15 

95 

95 

80 

80 

95 

95 

80 

80 

9 

9 

9 

9 

8 

8 

8 

8 

12 

12 

12 

12 

12 

12 

12 

12 

L 

R 

L 

R 

L 

R 

L 

R 

INSTRUMENTS 


1G3 


These  instruments  are  used  in^ivin^  the  final  bevel  ^'f--  i33 

to  the  gingival,  buceal,  and  lingual  walls  of  proximal  /fflj^ 

cavities,  especially  in  bicuspids  and  molars.  ^*^ 

Burs. — liurs  are  divided  into  two  groups,  indicated 
by  the  manner  in  which  the  blades  are  cut. 

Cavity  Burs:  Those  having  smooth  leaves. 

Dentate  Burs:  Those  having  the  leaves  cross-cut  or 
serrated  (forming  teeth)  (Fig.  133). 

The  first  class  or  group  (cavity  bur)  is  divided  into 
eight  groups,  indicated  by  the  form  of  the  point  or 
head,  as  follows:  Round  or  rose;  oval;  pear-shaped; 
bud-shaped;  inverted  cone;  wheel;  fissure  (square  end); 
fissure  (pointed)  (Figs.  134  to  141). 

Second  class  or  group  (dentate  burs)  is  divided  into 
four  groups:  Round;  pear-shaped;  fissure,  square  end; 
fissure,  pointed.     There  is  still  another  form  of  dentate  bur,  the  tapered 
fissure  (Fig.  142).     Both  square  end  and  pointed.     All  forms  of  burs  are 
made  in  from  six  to  eight  sizes,  varying  from  0.4  mm.  to  0.30  mm.  in 
diameter.     The  sizes  mostly  used,  however,  are  0.4,  0.6,  0.8,  0.10,  and 


Fig.  134 


Fig.  135 


Fig.  136   Fig.  137 


Fig.  138 


Fig.  139   Fig.  140   Fig.  141 


0.12  mm.  in  diameter.  Burs  are  catalogued  by  number,  but  it  is  apparent 
that  more  accuracy  would  be  attained  if  manufacturers  would  designate 
and  dentists  would  order,  by  the  diameter  of  the  head,  indicated  in  tenths 
of  a  millimeter.  This  is  simple  if  one  possesses  a  Boley  micromillimeter 
gauge  (Fig.  143).  This  instrument  is  so  useful  for  many  other  purposes 
that  every  dentist  should  possess  one.  Dentate  burs  are  designed  for  cut- 
ting enamel.  They  are  made  in  four  forms, as  follows:  Round;  pear- 
shaped;  fissure,  square  end;  and  fissure,  pointed.  They  are  made  in  six 
sizes,  but  the  writer  finds  that  the  pear  and  the  fissure,  both  square  end  and 


164 


TECHNIQUE  OF  CAVITY  I' RE  I' A  HAT  ION 


pointed,  in  two  sizes,  are  the  most  useful  (Fig.  144).  There  are  some 
places,  however,  where  the  tapered  fissure  is  very  effective  (Fig.  142). 
Cavity  burs  are  designed  for  cutting  dentin,  and  are  made  in  eight  forms, 
with  from  eight  to  twelve  sizes  in  each  form.      Here  again  the  writer 


Fig.  144 


LI   1  L 

580  581  568  569  557  558 


I 


FiQ.  142 

^^S)^!^f^^ 

-= — 

— ir    1) 

^^i^Cl 

—  ■'  -       '~~ 

-   -w 1) 

Fig.  143 


Boley's  micromillimeter  gauge. 

Fig.  145 

m       m      TO 


/ 


Vi      2      6       8      33  H   34     35    3()    38       49     51         50    57    85 


Fig.  146 


I  J 


TT 


selects  four  forms,  as  follows:    4  round,  5  inverted  cone,  2  bud,  and 
3  square-end  fissures  (Fig.  14.5). 

Disks,  Wheels,  and  Points. — These  are  sold  under  the  trade  names  of 
Carborundum  and  Gem.     Also  small  metal  disks  charged  with  Carbo- 


ins;truments 


105 


rundiim  or  diamond  dust.  Disks  are  efTective  in  opening  fissures. 
Small  wheels  and  points  are  very  useful  in  extending  enamel  walls  and 
shaping  eavities  for  inlays.  The  most  useful  forms  are  shown  in  Fig. 
140.  All  of  these  instruments  must  })e  kept  wet  while  in  use.  The 
selection  and  manner  of  using  instruments  will  be  treated  more  fully  in 
the  text  of  cavity  preparation. 


Fig.  147 


In  Nos.  1,  3,  4,  5,  and  7  are  shown  typical  cavities  which  occur  on  the  lingual  surfaces  of  the 
upper  incisors  and  cuspids.  When  prepared  as  in  Nos.  2,  6,  and  8  the  outline  is  established  to 
include  all  sulcate  grooves,  the  cavity  in  the  dentin,  which  has  been  given  the  mortise  form,  and  the 
enamel  walls  bevelled  sufficiently  to  give  strength  to  the  cavo-surface  angle. 


The  writer  believes  that  the  student  should  be  taught  in  his  technique 
course  how,  when,  and  where  to  use  the  bur;  he  will  thus  appreciate 
the  uses  and  relative  value  of  both  hand  and  engine  instruments  and  will 
not  attempt  enamel  cutting  and  other  unwise  uses  of  the  engine  when 
he  comes  to  operate  on  the  patient. 


166 


TECHNIQUE  OF  CAVITY  PREPARATION 


PREPARATION  OF  CAVITIES  BY  CLASSES 

First  Step. — Pit  and  Fissure  Cdvitics.-  Tht'se  occur  on  tlie  liii^nial 
surfaces  of  upper  incisors  and  cuspids.  Tiie  lingual  surface  of  uj)per 
molars,  the  buccal  surfaces  of  lower  molars,  but  most  fre(juently  on  the 
occlusal  surfaces  of  all  the  bicuspids  and  molars  (Figs.  147,  148,  149,  150, 
and  151).  As  these  cavities  are  usually  confined  to  the  surfaces  upon 
which  they  begin,  they  may  be  considered  as  inlays,  as  this  term  is  ap})lied 
in  mechanics;  their  ouUine  varying  as  influenced  by  the  form  and 
markings  of  the  surface  upon  which  they  occur. 

Fig.  148 


The  lingual  surfaces  of  the  upper  molars,  especially  the  first  molar,  frequently  show  cavities,  as  in 
Nos.  1  and  2.     The  preparation,  as  in  No.  3,  follows  the  same  rules  as  those  given  in  P"ig.  147. 


In  carpentry,  the  general  form  of  the  cavity  for  an  inlay  is  the  simple 
mortise  (No.  1,  Fig.  152).  Several  forms  of  its  application  to  teeth  are 
shown  in  Nos.  2,  3,  and  4,  Fig.  152.  In  many  locations,  because  of  the 
direction  of  the  enamel  rods,  this  simple  form  might  result  in  leaving 
some  enamel  rods  at  the  margin  of  the  cavity  unsupported  by  dentin. 
Fig.  153  (modified  from  Noyes)  show^s  how  this  might  occur.  This  con- 
dition is  overcome  by  laying  that  portion  of  the  wall  formed  by  the 
enamel  in  a  different  plane  from  that  formed  by  the  dentin  (Fig.  154). 
Fig.  155  shows  a  similar  cavity,  in  which  the  dentin  and  enamel  walls  are 
in  the  same  plane.     A  careful  study  of  the  sections  shown  will  establish 


PREPARATION  OF  CAVITIES  BY  CLASSES 


107 


Fig.  149 


In  the  lower  molars,  especially  the  first  molar,  cavities  occur  in  the  buccal  grooves,  Nos.  1  and  2. 
In  No.  3  is  shown  the  preparation  when  the  cavity  is  confined  to  the  terminal  fossa.  In  cavities 
like  Nos.  1  and  2  it  would  be  necessary  to  extend  the  cavity  to  the  occlusal  surface,  connecting  it 
with  the  occlusal  filling,  if  one  be  present. 


Fig.  150 


6»   9/   n^ 


The  teeth  from  which  these  pictures  were  made,  as  well  as  all  of  those  having  ca^'ities,  that  appear 
in  the  other  plates,  were  selected  from  a  large  number  of  teeth  similarly  decayed,  as  being  typical 
of  their  class.  If  lines  are  drawn  to  include  all  silicate  grooves  and  give  a  graceful  outline,  the  size 
and  form  of  the  prepared  cavity  will  be  indicated.     (See  Fig.  162.) 


1G8 


TECHNIQUE  OF  CAVITY  PREPARATION 


Fio.  151 


5  6  7  8 

These  pictures  will  repay  careful  study.  They  are  not  extremes,  only  types.  Draw  outlines 
to  include  all  sulcate  grooves,  and  at  the  same  time  preserve  all  the  cusp  formation  possible.  (See 
Fig.  162.) 

Fig.  1,52 


No.  1  show.s  the  simplest  form  of  morti.se  employed  in  mechanics.  No.  2  is  presented,  not  to 
show  a  practical  cavity,  but  to  bring  out  the  modification  necessary  to  establish  the  proper 
"bevel"  of  the  enamel  wall.  No.  3  shows  a  common  type  of  the  simple  mortise  as  applied  in  a 
lower  second  molar.  No.  4  illustrates  the  modification  necessary  to  include  all  susceptible  areas. 
It  is  still  a  simple  mortise. 


PREPARATION  OF  CAVITIES  BY  CLASSES 


109 


Fkj.  153 


This  excellent  section,  reproduced  from  a  photograph  in  the  writer's  possession  (by  Dr.  F.  B. 
Noyes),  shows  the  condition  of  the  enamel  rods  if  cavity  walls  were  laid  at  any  point  parallel  with 
the  vertical  lines.  A  study  of  this  picture  will  indicate  the  line  of  bevel  necessary  to  protect  the 
enamel  rods  at  any  point  between  the  sulcus  and  the  summit  of  the  cusps. 


Fig.  154 


Fig.  155 


This  section  shows  the  simple  mortise  form 
of  cavity  in  the  dentin  with  the  enamel  walls 
properly  bevelled  to  protect  the  enamel  rods. 


This  section  shows  a  cavity  where  the  dentin 
walls  and  the  enamel  walls  are  in  the  same 
plane.  This  form  of  mortise  is  permissible 
where  the  walls  are  so  located  that  the  enamel 
rods  will  be  protected  when  the  enamel  walls 
are  in  the  vertical  plane.  This,  or  some  slight 
modification,  is  necessary  when  amalgam  is 
used. 


170  TECHNIQUE  OF  CAVITY  PREPARATION 

the  fact  that  in  tlie  preparation  of  all  cavities  we  have  to  deal  with  two 
distinct  substances,  dentin  and  enamel,  and  that  it  is  in  the  dentin  that 
we  secure  the  seat  or  anchora^je  for  the  fillin^r.  Also,  that  the  structure 
of  the  enamel  makes  it  necessarv  that  it  should  he  so  cut  that  the  rods  at 
the  cavo-surface  an^le  will  rest  upon  sound  dentin.  If  we  divide  the 
walls  of  a  cavity  into  two  parts  and  think  of  that  portion  in  the  dentin 
as  "dentin  wall"  and  that  part  in  the  enamel  as  "enamel  wall"  it  will 
simplify  our  procedure. 

Fig.  156 
12  3 


4  5 

These  sections  were  made  from  teeth  in  which  the  surface  indications  were  no  greater  than  in  the 
smallest  cavities  shown  in  Figs.  150  and  151.  They  ilhistrate  the  behavior  of  caries  after  the  enamel 
has  been  penetrated. 

In  No.  2,  Fig.  152,  is  show^n  the  application  of  the  simple  mortise  to  a 
cavity  in  a  lower  second  molar.  Sections  of  similar  teeth  show  how  the 
direction  of  the  enamel  rods  modifies  the  simple  mortise  (Figs.  156  and 
157).  Following  the  prescribed  order  of  procedure,  we  first  open  the 
cavity  and  establish  its  outline.  In  tho.se  cavities  where  caries  has  not 
progressed  so-far  as  to  leave  the  enamel  unsupported,  it  is  best  to  open 
and  extend  the  fissures  with  dentate  burs,  either  pear-shaped  or  pointed 


PREPARATION  OF  CAVITIES  BY  CLASSES 

Fig.  157 


171 


5  6  7 

These  sections  are  from  some  of  the  teeth  shown  in  Fig.  151,  and  are  offered  as  instructive  exam- 
ples of  the  interior  spreading  of  caries.  Note  the  cutting  necessary  to  estabhsh  strong  enamel 
walls  in  some  of  them. 


Fig.  158 


This  cut  shows  a  worn  fissure  bur  which 
has  been  converted  into  an  effective  drill  for 
sxtending  fissures,  by  bi-bevelling  the  point. 


This  cut  shows  the  manner  of  using  a  drill 
made  from  a  worn  fissure  bur,  in  opening  and 
extending  fissures. 


172 


TECHNIQUE  OF  CAVITY  PREPARATION 


fissure  (Fig.  133).  Partially  worn  fissure  l)urs  may  he  made  into  efTective 
instruments  by  I )i-l)e veiling  the  end,  forming  a  drill  (  Fig.  ].'")S).  If  the  bur 
is  entered  in  a  pit  to  the  dento-enamel  junction,  and  the  cutting  done 


Fig.  100 

^ 

^5-5, 

./^ 

4k 

^ 

y 

^ 

ig 

Xy  >flr 

i 

,-.<^ 

^  J  ~'^"i  i 

r 

y^ 

1. 

i 

.  ^ 

^ 

4 

^^H^^Ty^S* 

p 

^ 

Manner  of  holding  an  instrument  by  the  "pen"  grasp,  and  the  position  of   the  fingers   to   provide 

a  "re.st." 


Fig.  161 


Manner  of  holding  an  instrument  by  the  "  palm  "  grasp,  with  the  position  of  the  thumb  to  provide 

a  "  rest." 


from  within  outward,  it  will  expedite  the  ^\ovk,  as  enamel  cuts  much 
easier  in  this  way  (Fig.  159). 

After  the  cavity  is  opened  in  this  way,  or  by  the  extension  of  the 
caries,  the  unsupported  enamel  is  split  off  with  chisels.     While  these 


PREPARATION  OF  CAVITIKH   BY  CLASSES  173 

may  be  used  by  hand  pressure  aloue,  it  is  usually  best  to  employ  the 
haud  mallet,  as  uuich  larger  pieces  may  be  sj)lit  oti'  iu  this  way  with 
less  discomfort  to  the  patieut.  lu  the  use  of  chisels  there  are  two  prin- 
cipal o'rasps — the  pen  grasp  (Fig.  100)  and  the  palm  and  thumb  grasp 
(Fig.  102).  With  either  of  these  grasps,  rests  and  guards  are  necessary. 
The  illustrations  will  show  the  manner  of  using  the  third  and  fourth 
finger  in  the  pen  grasp,  and  the  thumb  in  the  palm  grasp.  The  rule  for 
cavity  outline  in  these  pit  and  fissure  cavities  is  that  all  pits  must  l)e 
extended  until  the  enamel  rods  at  the  margin  of  the  cavity  rest  upon 
sound  dentin  and  no  sulcate  grooves  radiate  from  the  cavity  margin. 
All  fissures  must  be  extended  until  they  become  grooves.  A  study  of 
Figs.  148, 149, 150,  and  151  will  show  the  amount  of  extension  which  is 
necessary. 

Fig.  162 
1  2  3 


These  figures  illustrate  a  safe  preparation  of  some  of  the   cavities  shown  in   previous  plates,  and 
show  the  application  of  the  simple  mortise. 

Here  let  us  recall  the  definition  of  certain  terms  (from  Black) : 

Fossa  (plural  Fossae) :  A  rounded  or  angular  depression  in  the  surface 
of  a  tooth. 

Pit:  A  sharp-pointed  depression  in  the  enamel. 

Groove:  A  long-shaped  depression  in  the  surface  of  a  tooth. 

Sulcus  (plural  Sulci) :  A  notably  long-shaped  depression  in  the  surface 
of  a  tooth,  the  inclines  of  which  meet  at  an  angle.  A  sulcus  has  a 
developmental  groove  at  the  junction  of  its  inclines. 


174  TECHNIQUE  OF  CAVITY  PRE/'ARATION 

Fissure:  A  fault  in  the  surface  of  a  tooth  caused  i)y  the  imperfect 
joining  of  the  enamel  of  the  different  lobes. 

In  such  cavities  as  occur  from  faulty  union  of  the  enamel  along  devel- 
opmental lines  in  what  would  normally  be  fosste  and  grooves,  it  is  only 
necessary  that  the  walls  be  extended  until  all  enamel  unsupported  by 
dentin  is  removed  and  until  the  margins  are  unl)roken  by  sulcate 
grooves  leading  off  from  them,  which  would  prevent  the  j^erfect  finishing 
of  the  margins  of  the  filling. 

These  rules  have  been  observed  in  the  preparation  of  the  cavities  for 
the  illustrations  (Figs.  152  and  1()2). 

Second  Step. — Removal  of  Softened  Dentin. — After  the  cavity  is 
opened  all  softened  dentin  should  be  removed  with  spoon  or  discoid 
excavators  (Figs.  1 17, 1  IS,  1 19).  These  are  usually  held  by  the  pen  grasp 
(Fig.  160) .  The  first  cutting  is  made  with  a  sweeping  motion,  first  to  the 
right  and  then  to  the  left,  around  the  cavity,  just  below  the  dento-enamel 
junction;  the  deeper  portions  can  then  be  removed  with  a  lifting  motion 
of  the  blade.  When  we  begin  to  operate  upon  the  dentin  the  whole 
picture  of  its  structure  should  rise  before  us,  especially  the  intimate  rela- 
tion of  its  organic  portion,  the  fibrilhe,  with  the  pulp  and  the  possible 
change  in  its  structure  as  the  result  of  caries.  (See  Chapter  II.)  When 
a  cavity  presents,  the  first  thing  is  to  ascertain  its  extent,  how  much 
dentin  is  already  destroyed.  To  do  this  we  must  perform  the  first  i\\o 
steps.  Then  and  only  then  can  we  determine  intelligently  w^hat  the 
outline  of  the  cavity  must  be.  When  we  discover  that  in  a  majority  of 
cases  this  can  be  done  with  chisels  and  excavators  alone,  better  and 
easier  for  the  patient,  than  with  the  engine,  we  shall  have  gained  much  in 
the  esteem  of  the  patient  and  in  ability  as  an  operator.  Figs.  163,  164, 
and  165  show  occlusal  cavities  with  outline  established  and  decay 
removed. 

Third  Ste'^.—Shapim/  the  Cavity  for  Resistance,  Retention,  ami  Con- 
venience.— ^When  the  form  of  the  cavity  is  established  as  indicated  by  the 
extent  of  the  caries  and  the  cutting  necessary  to  remove  faults  in  the 
enamel  and  insure  perfect  margins  in  the  completed  filling,  it  remains 
for  us  to  determine  how  much  this  form  must  be  changed  to  meet  the 
above  requirements. 

\\Tien  the  first  two  steps  have  been  carefully  and  thoroughly  per- 
formed, many  cavities  need  l)Ut  little  modification  to  provide  the  neces- 
sary resistance,  retention,  and  a  form  convenient  for  the  insertion  of  a 
filling  (Figs.  163, 164,  and  165,  and  No.  1,  Fig.  166).  All  cavities  of  this 
type  may  be  considered  as  simple  inlays,  the  fault  or  hole  to  be  stopped 
with  a  mass  formed  to  fit  the  prepared  cavity  and  inserted  en  masse. 
Having  mastered  these  principles,  it  becomes  easy  to  modify  forms  to 
meet  the  demands  of  the  various  materials  and  methods  employed. 
Remember,  that  now  we  are  considering  only  simple  cavities,  those 
confined  to  one  surface,  and  having  continuous  surrounding  walls.     In 


PREPARATION  OF  CAVITIES  BY  CLASSES 


175 


No.  4,  Fig.  152,  we  see  the  form  the  meehanic  would  make,  the  depth  of 
his  cavity  varying  to  meet  the  demands  determined  l)y  the  nature  of  the 
material  employed  and  the  amount  of  stress  to  which  the  completed 
operation  is  to  i)e  subjected.  This  is  what  governs  us  in  the  amount  of 
resistance  and  retention  form  we  give  to  our  cavities. 


Fig.  163 


Fiu.  164 


Fig 

165 

Bv 

\ 

•  1          H 

y'^'^l 

K^  fl 

m 

Ih 

These  sections  show  the  form  of  ca^-ities  after  the  unsupported  enamel  has  been  broken   down 
and  the  softened  dentin  removed.     This  comprises  the  first  two  steps  in  cavity   preparation. 

Referring  again  to  the  occlusal  cavities  in  bicuspids  and  molars,  we 
find  that  all  the  stress  save  that  exerted  by  such  adhesive  substances  as 
sticky  candy,  etc.,  which  occur  in  the  food,  falls  within  a  radius  of  180 
degrees  (Fig.  120). 

Reference  to  sections  of  the  teeth,  appearing  in  the  illustrations,  show^s 
that  the  position  of  the  pulp  regulates  the  depth  of  the  cavity  which  it  is 


17G  TECIIMQl'E  OF  CAVITY  PRE  I' A  RAT  I  ON 

safe  to  establish  in  vital  teeth.  A  rule  has  been  promulcrated  that  the 
depth  of  a  cavity  having  parallel  walls,  should  l)e  e(|ual  to  its  diameter 
(No.  2,  Fig.  J()(),  and  Xo.  2,  Fig.  i(;7).    wi^m,  this  is  not  possible,  we  may 


1  2  3 

No.  1  shows  an  occlasal  cavity  in  a  bicuspid  after  the  enamel  walls  have  been  sufficiently  extended 
and  all  softened  dentin  removed.  No.  2  show.s  the  depth  of  cavity,  as  compared  with  the  di:imeter, 
necessary  to  provide  sufficient  retention  when  the  walls  of  the  cavity  are  parallel  in  both  dentin 
and  enamel.  No.  3  shows  the  dovetail  form  in  the  dentin  to  provide  additional  retention,  with  the 
enamel  walls  in  a  distinctly  different  plane,  to  insure  protection  to  the  enamel  rods. 


Fig. 

167 

r 

^ 

1 

m 

^ 

i 

I 

1 

^^H 

[m 

1 

1 

1 

L* 

^^H 

^^^gl 

■ 

I 

ii 

i^fl 

No.  1  shows  the  enamel  bevel  which  is  necessary  when  gold  is  the  material  u.sed  for  the  filling. 
No.  2  shows  an  amalgam  filling.  This  cavity  hits  the  en;unel  walls  in  the  siune  plane  with  the 
dentin  walls  in  order  that  the  margins  of  the  filling  may  be  protected  from  fracture. 

resort  to  the  dovetail  form  (No.  3,  Fig.  100,  and  No.  1 ,  Fig.  107).  Refer- 
ring again  to  the  sections,  it  w\\\  be  seen  that  in  the  majority  of  cavities 
the  enamel  walls  must  be  divergent,  i.  c,  in  a  different  plane  from  the 


r REPARATION  OF  CAVITIES  BY  CLASSES  177 

dentin  walls;  conseqnently,  the  retentive  form  of  the  cavity  is  confined 
to  the  dentin. 

In  mechanics,  when  the  simple  mortise  is  insufficient  to  furnish  the 
necessary  resistance,  the  dovetail  mortise  is  employed.  Where  the 
filling  is  inserted  in  a  plastic  form  or  built  in  piecemeal,  as  with  gold 
or  tin,  this  form  is  easily  filled;  but  when  the  filling  is  inserted  en  masse, 
as  in  an  inlay,  the  dovetail  form  must  be  made  after  the  inlay  is  fitted, 
and  the  cementing  substance  depended  upon  to  key  the  piece  against 
stress,  if  necessary.  In  most  cases  where  decay  has  not  destroyed  suffi- 
cient dentin  to  allow  a  proper  depth  to  permit  parallel  walls  (where 
diameter  is  greater  than  depth),  it  is  necessary  to  employ  the  dovetail 
form,  i.  e.,  to  make  the  dental  walls  convergent  as  they  rise  from  the 
pulpal  wall  or  floor  of  the  cavity  (No.  3,  Fig.  16(3,  and  No.  1,  Fig.  167). 
It  is  not  always  necessary  that  the  dovetail  form  be  given  to  all  of  the 
walls.     It  is  often  sufficient  to  apply  it  to  only  two  opposite  walls. 

Instrumentation. — As  the  box  or  mortise  form  results  in  definite  angles 
at  the  junction  of  the  peripheral  walls  with  the  pulpal  or  axial  wall,  it 
is  necessary  to  employ  instruments  the  edge  of  which  is  at  right  or  acute 
angles  with  the  axis  of  the  blade;  such  instruments  are  the  hatchet  and 
hoe  excavators  (Figs.  123  and  124).  In  burs,  the  inverted  cone  and 
the  square  end  fissure  are  indicated. 

In  using  burs  in  dentin  in  vital  teeth  it  will  be  found  much  less  pain- 
ful and  quite  as  effective  to  use  the  small  sizes.  In  establishing  the  proper 
form  it  is  best  to  get  the  shape  roughly  with  burs,  smoothing  the  walls 
and  defining  the  angles  with  excavators. 

If  the  "convenience  points"  recommended  by  Black  are  indicated, 
they  are  best  formed  with  small  inverted  cone  burs  (Fig.  145). 
.  Bevelling  and  Finishing  Enamel  Walls. — The  bevel  or  plane  of  the 
enamel  walls  is  indicated,  first,  by  the  direction  of  the  enamel  rods  at 
the  border  or  margin  of  the  cavity;  second,  by  the  character  of  the 
filling  material.  Observation  of  the  line  of  cleavage  as  the  enamel  splits, 
when  using  the  chisel,  will  indicate  the  bevel  or  inclination  of  the  enamel 
wall  necessary  to  insure  that  the  rods  at  the  cavo-surface  angle  rest  upon 
dentin  and  that  they  are  supported  by  a  buttress  of  shorter  rods  which 
are  covered  and  protected  by  the  filling  or  inlay.  (See  sections  shown  in 
illustrations.)  In  inlays  or  fillings  of  gold,  which  possess  ductility, 
tenacity,  and  edge  strength,  the  margins  of  the  filling  may  show  more 
acute  angles  in  section  without  danger  (No.  l,Fig.  167).  'When  porce- 
lain, tin,  amalgam,  or  cement  is  used,  it  is  necessary  to  modify  the  incli- 
nation or  bevel,  that  the  angle  shown  in  section  may  be  sufficiently 
strong  to  avoid  the  danger  of  fracture  or  chipping  of  the  filling  under 
stress  (No.  2,  Fig.  167).  These  conditions  may  make  it  necessary  to 
extend  the  enamel  walls  at  certain  points  beyond  the  lines  indicated  by 
the  rules  for  establishing  outlines,  already  noted. 

Whatever  the  inclination  of  enamel  walls,  they  should  always  show  a 
12 


178  TECHNIQUE  OF  CAVITY  PREPARATION 

true  plane  at  any  point  in  section.  (See  prepared  cavities  in  section.) 
A  short  supplemental  bevel  of  the  occlusal  fifth  of  the  wall  (cavo-surface 
anfi^le)  may  he  n;iven  to  insure  the  huttrcssiiif;  already  referred  to. 

Instrumentation. — The  final  shaping  and  finishing  of  enamel  walls  is 
best  accomplished  with  chisels  and  gingival  margin  trimmers,  'i'hese 
must  he  razor  sharp.  Fine  grinding  stones  and  disks  may  be  used,  but 
the  danger  is  always  present  of  destroying  the  [)lane  surface — definitive- 
ness  of  the  cavo-surface  angle — leaving  the  wall  rounded  as  in  No.  1, 
Fig.  IGG.  This  must  be  avoided,  because  it  is  impossible  to  properly 
finish  the  margins  of  a  filling  under  these  conditions.  The  most  useful 
forms  of  chisels  are  those  shown  in  Figs.  129,  130,  LSI,  and  132. 

Final  Touches  to  the  Cavity. — As  freshly  cut  surfaces  are  clean,  it  fol- 
lows that  the  final  cutting  of  all  walls  should  be  done  after  the  application 
of  the  rubber  dam  or  some,  other  equally  efficient  means  of  excluding 
the  fluids  of  the  mouth.  When  the  instrumentation  is  complete,  all 
surfaces  should  be  carefully  wiped  with  cotton,  spunk,  or  bibulous 
paper.  The  practice  of  flooding  the  cavity  with  drugs  for  their  supposed 
antiseptic  value  is  unnecessary  if  the  cavity  is  properly  prepared — all 
decayed  dentin  removed.  If  asepsis  cannot  be  secured  by  instrumenta- 
tion alone,  the  cavity  should  be  sterilized  before  the  final  preparation 
of  the  enamel  walls.  When  the  cavity  is  to  receive  an  inlay,  the  walls 
should  be  protected  in  the  interim  between  the  preparation  of  the  cavity 
and  the  cementing  of  the  inlay,  by  a  temporary  stopping  and  finally 
washed  with  alcohol  or  ether.  A  safe  rule  is  never  to  permit  the  contact 
of  the  fluids  of  the  mouth  or  any  viscid  or  oily  substance  after  the  final 
preparation. 

SMOOTH  SURFACE  CAVITIES 

Cavities  in  the  Gingival  Third  of  Labial,  Buccal,  and  Lingual  Surfaces  of 
the  Teeth. — As  these  cavities  are  confined  to  one  surface,  they  have  con- 
tinuous surrounding  walls,  and  come  under  the  class  of  simple  inlays; 
consequently,  the  rules  for  dentin  form  and  enamel  bevels  are  the  same 
as  in  pit  and  fissure  cavities.  The  cause  for  the  occurrence  of  these 
cavities  cannot  be  discussed  here,  but  should  be  considered  in  establishing 
the  outlines  of  the  cavity.  The  extent  of  each  cavity  must  be  governed 
by  the  conditions  existing  in  that  particular  case.  Reference  to  Fig.  KiS 
will  show  that  these  cavities  are  not  always  confined  to  the  gingival 
third.  Even  so,  they  may  be  distinguished  from  those  cavities  which 
have  their  beginning  in  pits  and  fissures,  as  this  fact  influences  their 
outline  (Figs.  147  and  148).  The  preparation  of  these  cavities  is  shown 
in  Nos.  3,  4,  and  5,  Fig.  168. 

Cavities  in  the  Proximal  Surfaces  of  Incisors  and  Cuspids  Which  do  Not 
Involve  the  Incisal  Angle. — These  are  shown  in  Figs.  169  and  170.  These 
cavities  should  have  their  margins  extended  until  they  are  so  placed  as 


SMOOTH  SURFACE  CAVITIES  179 

to  be  easily  cleansed.    Specimens  are  shown  in  Figs.  171  and  172.    When 
the  cavity  is  opened  it  will  present  an  appearance  like  Fig.  173.    In  com- 

FiG.  108 


5  6  7 

Nos.  1  and  2  show  the  characteristic  cavities  which  occur  in  the  gingival  third  of  the  labial  sur- 
faces of  the  teeth.  Nos.  3  and  4  show  the  preparation  of  this  class  of  cavities  which  will  insure 
the  best  results  mechanically  and  artistically.  The  lower  group  (Nos.  6,  7,  and  8)  offers  a  study 
of  typical  cavities  which  occur  on  the  smooth  portion  of  buccal  surfaces,  usually  in  the  gingival 
third.     In  No.  5  may  be  seen  a  typical  cavity  preparation  for  this  class  of  cavities. 

pleting  the  cavity  form,  the  gingival  wall  is  made  flat  in  both  horizontal 
planes,  with  the  axial  wall  meeting  it  at  a  right  angle.  The  labial  and 
lingual  walls  meet  the  gingival  at  an  acute  angle.     They  also  meet  the 


180  TEL'HNIQLE  OF  CAVITY  I'REI'ARATION 

axial  wall  at  a  slightly  acute  angle  in  the  gingival  third.  This  forms 
two  acute  point  angles  and  gives  retentive  form  in  the  base,  or  gingival 
third. 

Vir..  100 

1  2  ■.'.  i 


No.  1  shows  a  gold  filling  in  which  recurrent  decay  has  begun  at  the  labio-gingival  and  linguo- 
gingival  angles.  No.  2,  Fig.  176,  shows  the  cavity  after  the  filling  wa.s  removed,  and  No.  1  (sanie 
Fig.)  is  the  writer's  suggestion  for  a  correct  preparation,  which  .should  include  the  area  of  recurrent 
decay.     Nos.  2  to  10  are  offered  for  study  as  representing  typical  proximal  cavities. 

The  incisal  anchorage  i.s  formed  hy  making  the  labial  and  lingual  walls 
meet  the  axial  wall  at  right  angles  in  the  incisal  third,  but  the  point 
angle  formed  by  their  union  is  an  acute  angle  with  the  axial  wall.  This 
gives  the  third  leg  of  the  triangular  anchorage,  which  is  well  shown  in 
Fig.  174  and  in  Xo.  4,  Fig.  175.  There  are  no  undercuts  or  angles  formed 
by  the  union  of  the  labial  and  lingual  with  the  axial  wall  in  the  middle 
third.     No.  1,  Fig,  169,  shows  a  gold  filling  where  recurrent  caries  is 


SMOOTH  SURFACE  CAVITIES  181 

beoiiiniiio-  at  the  labio-^-in^ival  and  Hnp;uo-f]^in^ival  angles.  The  original 
preparation  of  this  cavity  is  shown  in  No,  2,  Fig.  17G.  If  this  cavity  had 
been  originally  prepared,  as  in  No.  1,  Fig.  176,  recurrent  caries  would 
not  have  appeared.  Fig.  177  shows  labial  and  lingual  views  of  this  type 
of  cavities.     In  establishing  the  labial   margin  of  these  cavities,  care 

Fig.  170  Fig.  171  Fig.  172 


Fig.  170. — This  section  is  from  the  tooth  shown  in  No.  2,  Fig.  60.  and  is  worthy  of   study. 
Fig.  171. — Shows  a  typical  preparation  for  cavities  like  those  shown  in  Nos.  1  to  5,  Fig.  169. 
Fig.  172. — A  typical  preparation  for  cavities  in  the  lower  incisors  and  cuspids,  like  those  shown 
in  Nos.  6  to  10,  Fig.  169. 

Fig.  173  Fig.  174 


Shows    a   cavity   after   the   first  two    steps  Shows    a   cavity    where   conditions  necessi- 

have  been  performed  (establishing  the  outline  tated   a   little  broader  cutting.     Observe  that, 

and  removing  all  softened  dentin).  no  matter  what  the  size  of    the  cavity,   the 

general  form  is  the  same. 

should  be  taken  to  avoid  the  semicircular  form  so  often  seen.  There 
is  a  harmony  of  lines,  as  well  as  a  harmony  of  sound  and  color,  and  the 
form  shown  in  the  illustrations  is  more  in  harmony  with  the  general 
outlines  of  the  teeth.  The  lingual  w^all  should  be  carried  far  enough  on 
to  the  lingual  surface  to  include  the  linguo-marginal  ridge.     Experience 


182 


TECHNIQUE  OF  CAVITY  PREPARATION 

Fi.;.  17.-, 


No.  1  shows  a  tooth  in  which  caries  ha.s  resulted  in  sufficient  loss  of  substance  to  demand  extra 
incisal  anchorage.  No.  2  shows  the  first  stage  in  preparation,  and  No.  3  a  lingual  view  of  the 
second  stage.'  No.  4  is  a  section  showing  the  dovetailed  form  of  two  cavities  where  ail  of  the 
incisal  point  anchorage  is  provided  in  an  emphasized  point  angle,  and  is  entirely  within  the  cavity 
walls. 

Fio.  176 


1  2 

No.  2  shows  the  cavity  as  originally  prepared  for  the  gold  filling  shown  in  No.  1.  Fig.  169.  No.  1 
shows  the  writer's  preparation  of  the  same  cavity.  (It  was  prepared  in  the  same  tooth,  there 
being  no  recurrent  decay  in  the  cavity.) 

'  The  writer  uses  this  term  to  indicate  the  order  in  which  a  compound  cavity  is  prepared,  and 
should  not  be  confused  with  "step."  The  forming  of  the  main  cavity  is  the  first  "stage,"  and  the 
■  'step"  is  formed  in  the  second  '  'stage." 


SMOOTH  SURFACE  CAVITIES 


183 


has  shown  that  recurrent  caries  is  frequent  where  the  lino;ual  wall  is  left 
well  within  the  linirual  embrasure. 


Fig.  177 


Fifi.  178 


1 

2 

r" 

'^^^^^B 

-• 

M 

i 

-'^^^^^l 

il 

^m 

•■'M^H 

i^^^^i 

'a-^'tH 

^^^^H 

L 

■v.r-.    \-;J 

^ 

J 

No.  1  shows  the  labial  and  No.  2  the  lingual  outline 
of  average  cavities  which  do  not  involve  the  incisal 
angle.  This  form  is  more  in  harmony  with  the  general 
outlines  of  the  teeth  than  the  semicircular  form  so 
often  seen. 

Fig.  179 


Shows  the  application  of  the 
"dovetailed  mortise"  to  a  cavity 
in  a  cuspid  tooth.  This  form  is 
applicable  in  teeth  having  short, 
thick  crowns. 


Cavities  in  both  upper  and  lower  incisors  which  do  not  involve  any  more   loss   of   substance  than 
shown  in  No.  2  may  be  prepared  as  in  No.  1 .  emphasi:;ing  the  gingival  and  incisal  point  angles. 

Instrumentation. — If  caries  has  progressed  so  that  the  enamel  is  under- 
mined, the  chisel  (No.  48  S,  Fig.  131)  is  indicated  for  estabhshing  cavity 
outlines.  "\Mien  the  enamel  is  not  undermined,  a  small  round  bur  should 
be  used  to  cut  away  the  dentin  immediately  beneath  the  enamel,  after 
which  the  enamel  may  be  cut  away  with  chisels.     After  removing  the 


184 


TECIISIQUE  OF  CAVITY  rREPARATIOX 


Fig.  180 


JI^^^^^^^B              '-^n 

I 

Nos.  1  and  2  show  labial  and  lingual  views  of  cavities  like  No.  1,  Fig,  17.5.  where  the  '  'incisal  step" 
is  employed.  Nos.  3  and  4  show  the  lingual  '  "step  "  in  similar  cavities  in  such  teeth  as  are  too  thin 
in  the  incisal  third  to  warrant  the  employment  of  the  incisal  "step." 


Fig.  181 


The  application  of  the  "lingual  step''  in  an  extreme  case  for  a  gold  iulay. 


SMOOTH  SURFACE  CAVITIES 


185 


softened  dentin  with  small  right  and  left  ,s])()()n  excavators,  the  retention 
form  is  made  with  small  inverted  cone  hurs,  completinf^  the  ginoiyal 
point  angles  with  small  hoe  excavators  and  the  incisal  point  angle  with 
a  small  hatehet  angle  2S  (Fig.  125). 

The  final  enamel  bevel  is  made  with  sharp  chisels.  Sandpaper  disks 
and  strips  should  be  avoided  because  of  the  danger  of  rounding  the 
enamel  walls.     In   proximal   cavities   in   the  cuspids   the   preparation 


Fig.  182 


These  teeth  are  reproduced  aa  typical  of  most  cavities  where  the  marginal  ridge  has  not  been 
broken  down,  and  show  very  clearly  how  form  and  contour  influence  the  lateral  spreading  of  canes 
on  the  surface  of  the  enamel. 

shown  in  Fig.  178  may  be  employed.  This  is  an  application  of  the  dove- 
tail mortise.  In  all  this  class  of  cavities  the  outline  should  be  such  as  to 
produce  the  best  artistic  effect,  and  also  to  permit  the  easy  and  direct 
introduction  of  the  filling  material  with  the  least  'possible  separation. 

Cavities  in  the  Proximal  Surfaces  of  Incisors  and  Cuspids  which  Involve 
the  Incisal  Angle.— In  these  cavities  the  outline  is  indicated  by  the 
amount  of  tooth  substance  missing  after  all  unsupported  enamel  and 
softened    dentin   has   been    removed.     The  retention  in   the 


o'ingival 


186 


TECHNIQUE  OF  CAVITY  PREPARATION 


third  is  of  the  same  form  and  shaped  with  the  same  instruments  as  in 
those  cavities  where  the  incisal  an^le  is  not  involved.  When  the  loss  of 
tooth  substance  is  not  greater  than  that  shown  in  Xo.  2,  Fig.  179,  the 
incisal  retention  may  he  made  between  the  enamel  plates  (No.  1,  Fig. 
170).  When  this  loss  is  so  great  as  to  ref|uire  a  greater  bulk  of  metal  to 
restore  contour  than  that  within  the  cavity,  as  in  Xo.  1,  Fig.  175,  we  must 
secure  some  other  kind  of  incisal  retention.  Figs.  17")  and  ISO  show 
the  two  forms,     'i'lie  incisal  step  i>  cnijjloycd  in  teeth  uliieli  liaxc  been 


Fig.  183 


These  molars  illustrate  the  sanie  points  as  those  in  Fig.  1S2. 

abraded  or  those  that  are  thick  in  the  incisal  third.  The  lingual  step  is 
only  u.sed  where  the  teeth  are  .so  thin  in  the  incisal  third  as  to  preclude 
the  u.se  of  the  incisal  step.  In  the.se  cavities,  as  in  those  of  the  former 
class,  the  retention  form  is  made  with  inverted  cone  burs,  completing  all 
angles  with  small  hoe  excavators,  and  the  enamel  margins  finished  with 
.sharp  chisels  and  trimmers. 

In  preparing  these  cavities  it  is  Ijest  to  complete  the  preparation  of  the 
gingival  third  before  making  the  incisal  or  lingual  step  (Xo.  2,  Fig.  175). 


SMOOTH  SURFACE  CAVITIES 


187 


If  ^'old  inlays  are  to  be  inserted,  tlie  same  cavity  form  is  made  when  the 
ineisal  step  is  employed,  except  that  all  point  angles  are  less  pronounced. 
If  the  lingual  retention  is  necessary,  the  cavity  is  modified,  as  in  Fig,  181, 
and  the  inlay  inserted  from  the  lingual  surface. 

Cavities  in  Proximal  Surfaces  of  Bicuspids  and  Molars  (Figs.  1 82  anc  183) . 
— As  these  cavities  always  involve  the  occlusal  marginal  ridge,  except 
where  die  adjoining  tooth  is  missing,  they  come  in  the  class  of  mortises 


Tiu.  184 


Fig.  185 


The  simple  mortise  of  mechanics  where  two 
surfaces  are  involved. 


The  application  of  the  simple  "dovetailed 
mortise"  to  a  molar  cavity  where  the  buccal 
and  lingual  walls  are  sufficiently  strong  to 
warrant  this  style  of  preparation. 


Fig.  186 


In  mechanics,  this  would  be  a  "compound  mortise." 


shown  in  Fig.  184.  Where  there  is  no  decay  on  the  occlusal  surfaces, 
this  simple  mortise  form  may  be  employed,  providing  that  the  buccal 
and  lingual  walls  are  sufficiently  strong  to  retain  the  filling  against  the 
stresses  to  which  it  is  subjected  (Fig.  185).  When  there  is  a  cavity  on 
the  occlusal  surface,  or  where  caries  has  weakened  the  buccal  or 
lingual  wall,  the  auxiliary  mortise  or  step  in  the  occlusal  surface  must  be 
made.   Fig.  186  illustrates  this  double  mortise,  and  Figs.  187, 188,  and  189 


188 


TECHNIQUE  OE  CAVITY  PREPARATION 


show  its  iij)plitati()n  to  molar  teeth.     The  preparation  of  this  form  of 
cavity  is  made  hy  first  opening  the  cavity  with  chisels  (No.  2,  F'ig.  190). 


Fig.  187 


Fic.  188 


The  application  of  the  "compouiKl  mortise" 
or  "step"  to  :i  molar  cavity. 


A  proximal  view  showing  the  application 
of  the  "compound  mortise"  to  a  cavity  in  a 
molar.  Note  the  supportiiiK  dentin  between 
the  cusps. 


Fu;.  ISO 


The  line  on  this  section  shows  the  planes  and  angles  in  a  typical    "step"    cavity. 


The  next  step  after  removing  the  softened  dentin  is  to  make  the  gingival 
wall  flat  in  both  horizontal    planes  forming  the  seat.     The  axial  wall 


SMOOTH  SURFACE  CAVITIES 


189 


should  be  parallel  with  the  perpeiulicular  axis  of  the  tooth,  which  will 
result  in  a  right  angle  with  the  gingival  wall  (Fig.  189).  'fhe  buccal  and 
lingual  dentin  walls  should  form  right  angles  with  the  axial  wall  and  the 
enamel  walls  bevelled  as  in  Fig.  191.     This  is  done  with  inverted  cone 

KiG.    190 


No.  1  shows  a  cavity  in  a  bicuspid  No.  2  is  a  cavity  after  unsupported  enamel  has  been  broken 
down  and  all  softened  dentin  removed.  No.  3  shows  the  modification  necessary  to  produce  the 
completed  cavity. 

Fig.  191 


A  step  cavity  in  a  bicuspid,  which  shows  again  how  the  dentin  is  preserved  to  support  the  cusps. 
Fig.  192  Fig.  193  Fig.  194 


Several  applications  of  the  "step"  cavity  to  molars.  In  all  of  these  the  effort  has  been 
made  to  meet  the  requirements  of  a  safe  cavity  outline  for  the  enamel  with  the  least  sacrifice 
of  dentin  in  securing  retention  form. 


190 


TECHNIQUE  OF  CAVITY  PREPARATION 


or  scjuare  end  fissure  burs,  and  chisels  for  the  enamel  wall,  emphasizing 
the  angles  with  hoe  excavators.  The  step  is  formed  in  the  same  way 
and  with  the  same  instruments  as  a  simj)le  ])it  and  fissure  cavity.  The 
preparation  should  he  such  as  to  permit  the  insertion  of  a  cast  inlay.  If  a 
welded  gold   filling   is  decided   upon,  it   is  only  necessary  to  emphasize 


Fig.  195 


Fk;.  190 


A  section  showing  the 
planes  and  angles  in  an  ex- 
tensive "step"  cavity. 


An  occlusal  view  of  the  cavities  shown  in  Figs.  188,  192, 
193,  and  194.  Thes3  show  that  the  form  of  the  auxiliary 
cavity  or  "step"  was  determined  by  the  sulcate  grooves. 


Ki<:.  197 


A  section  of  one  of  the  teeth  shown  in  Fig.  182,  illustrating  the  necessity  for  the  liberal    cutting 
seen  in  some  of  the  previous  pictures. 


the  point  angles  with  inverted  cone  burs  and  hoe  excavators.  If  amal- 
gam is  to  be  used,  the  bevel  of  the  enamel  walls  must  be  less,  especially 
on  the  occlusal  surface.  The  illustrations  show  the  .several  types  of  this 
form  (Figs.  192,  193,  194,  195,  and  196). 

One  important  point  is  to  retain  all  the  dentin  possible  between   the 
cusps.     (See  illustrations.) 


CHAPTER    VIII 

EXCLUSIOxN  OF  MOISTURE— EJECTION  OF  THE  SALIVA- 
APPLICATION  OF  THE  DAM  IN  SIMPLE  CASES,  AND 
IN  SPECIAL  CASES  PRESENTIN(r  DIFFICULT  COM- 
PLICATIONS—NAPKINS AND  OTHER  METHODS  FOR 
SECUTIING  DRYNESS 

By  LOITIS  JACK,  D.D.S. 


Fig.   198 


The  interference  of  the  secretions  of  the  nioidh 
constitutes  an  obstacle  to  the  treatment  of  the 
teeth.  In  some  instances  the  flow  is  naturally 
excessive,  and  in  all  eases  it  is  stimulated  by  the 
operative  procedures. 

An  excessive  flow  of  saliva  is  uncomfortable  to  the 
patient;  its  accumulation  also  impedes  the  operation, 
and  interferes  with  the  view  of  parts  by  refracting 
the  rays  of  light. 

During  the  preparation  of  accessible  cavities, 
particularly  those  of  the  upper  front  teeth  and  the 
occlusal  surfaces,  the  accumulation  may  be  carried 
off  by  the  use  of  a  saliva 
ejectoi',  a  simple  form  of 
which  is  shown  in  Fig.  198, 
which  form,  or  some  modifi- 
cation of  it,  is  used  when  a 
connection  can  be  made  with 
the  water  supply,  and  ordin- 
arily it  is  used  in  association 
with  the  fountain  cuspidors. 
Another  form,  which  is  con- 
nected with  a  small  reservoir 
of  water,  is  shown  in  Fig.  199. 
Either  of  these  forms  has  a 
further  use  for  drawing  off 
the  saliva  in  connection  with 
the  employment  of  the  rubber 
dam  to  lessen  the  discomfort 
of  the  patient. 


Fic.   199 


(191) 


192  EXCLUSION  OF  MOISTURE 


USE  OF  THE  RUBBER  DAM 


During  the  preparation  of  cavities  on  the  proximal  surfaces  of  tlie 
bicuspids  and  molars  where  it  is  essential  to  have  unrestricted  view 
and  the  exclusion  of  blood,  the  presence  of  which  is  inseparable  from 
thorough  preparation  of  the  cervical  margins,  it  is  necessary  to  make  use 
of  the  riihher  dam.  When  used  for  this  purj)ose  the  material  generally 
becomes  impaired  by  the  action  of  the  instruments  in  their  free  use 
at  the  cervix;  but  the  economy  of  time  and  the  essentials  of  thorough 
performance  of  this  class  of  operations  warrant  the  application  in  many 
cases  during  this  portion  of  the  treatment. 

When  the  case  is  ready  for  the  filling  process,  a  new  piece  of  the  dam 
should  be  prepared,  and  adjusted  with  great  care  to  prevent  the  ingress 
of  the  least  moisture.  Without  this  appliance  the  greatest  skill  is  power- 
less to  secure  sound  results  in  large,  difficult,  or  complicated  cases. 
The  introduction  of  this  invention  by  the  late  Dr.  Sanford  C.  Barnum 
has  made  it  possible  to  secure  sterility  of  the  field  of  operation  and  to 
execute  with  gold,  operations  which  previously  were  impossible;  while 
not  the  leaot  advantage  resulting  from  its  use  is  that  the  operator  has 
free  use  of  the  left  hand  to  assist  the  right. 

Quality  of  the  Rubber. — The  quality  of  the  rubber  greatly  modifies 
the  facility  of  its  application.  It  should  be  of  medium  thickness  and 
of  light  color,  as  it  then  absorbs  less  light.  It  should  be  freely  exten- 
sible, and  so  elastic  that  when  the  thumb  is  forcibly  pressed  into  it  it 
returns  to  its  normal  form  on  the  removal  of  the  force.  If  it  responds 
to  this  test  it  will  not  tear  if  fairly  applied. 

The  size  and  form  of  the  piece  should  be  such  as  to  avoid  encmn- 
bering  the  face  of  the  patient  and  to  permit  the  lateral  extension  to  be 
folded  out  of  the  way  in  such  manner  as  to  prevent  obstruction  of  the 
view.  The  form  generally  best  suited  is  a  triangle,  which  form  also 
permits  of  its  most  economical  use. 

For  the  front  teeth  the  piece  should  be  moderately  small;  for  the 
bicuspids  and  molars  the  size  should  be  ample,  and  is  best  adapted 
when  cut  from  strips  about  seven  and  a  half  inches  in  width. 

The  selected  piece  should  have  holes  cut  in  it  of  such  size  as  to  corre- 
spond with  the  dimensions  of  the  teeth  over  which  it  is  to  pass.  When 
more  than  one  hole  is  required,  the  holes  should  be  at  such  distances 
apart  as  will  present  a  sufficient  amount  of  material  to  allow  for  the 
take-up  in  the  application,  so  that  the  strait  which  passes  between 
the  teeth  shall  be  sufficient  to  allow  the  edge  to  be  carried  upward  to 
form  a  valve  at  the  cervices  of  both  teeth  and  not  be  under  such  strain 
as  to  interfere  with  the  valvular  action  of  the  edges  of  the  rubber.  At 
the  same  time  there  should  be  no  excess  to  hamper  the  view  or  interfere 
with  the  placement  of  the  filling  material.     Ordinarily  two  or  more 


USE  VF   THE  RUBBER  DAM 
Fig.  200  Fig.  202 


193 


Pig.  201 


a  b        d         c 

Diagrammatic  drawing:  form  of  valve. 

teeth  on  each  side  of  the  tool  1 1 
which  is  to  be  operated  upciii 
should  be  passed  through  tin* 
rubber  dam  to  give  great<  r 
security  to  its  adjustment  n-. 
well  as  convenience  in  oper.i- 
ting. 

Attention  to  the  valvular  ai- 
rangement  of  the  dam  at  tlu' 
cervix  will  avoid  subsequent 
difficulty,  and  will  prevent,  hi 
many  instances,  the  infliction 
of  pain  in  using  ligatures  e>- 
cept  upon  the  tooth  und<  r 
treatment  and  the  adjaceni 
one. 

The  diagrammatic  appeal - 
ance  of  this  valve  is  shown  by 
Fig.  200,  and  in  perspective  by 
Fig.  201,  a,  b,  c,  d. 

The  holes  in  the  rubber  may  be  formed  with  a  punch  of  suitable 
size,  which  should  be  forced  upon  the  end  of  a  close-grained  piece  of 
hard  wood.    They  may  be  made  with  a  little  practice  by  drawing  the 
13 


The  Ainsworth  punch. 


194 


EXCLUSION  OF  MOISTURE 


rubber  over  a  round-ended  instrument  with  some  force,  and  pricking 
the  rubber  at  a  suitable  point  with  a  sharp  knife,  when  a  round  section 
escapes.  The  difference  in  size  of  the  holes  is  determined  by  the  distance 
from  the  end  of  the  instrument  at  which  the  piuicture  is  made.  The 
determination,  however,  of  size  and  distance  is  not  easily  made  in  this 
manner.  The  best  appliance  for  the  purpose  is  the  Ainsworth  punch 
(Fig.  202),  with  which  complete  control  of  size  and  distance  may  be 
easily  effected. 


Fig.  204 


Fig.  205 


For  central  incisors.  For  up^jer  bicuspids  and  molars.      For  lower  bicuspids  and  molars. 


Fig.  206 


The  arrangement  of  the  holes  in  the  triangular  piece  should  differ 
for  each  section  of  the  mouth. 

Fig.  203  shows  a  piece  for  the  central  incisors.  The  figures  represent 
inches. 

Fig.  204  shows  the  arrangement  of  holes  for  the  upper  hicuspids  and 
molars.  It  will  be  observed  that  the  line  of  holes  is  not  parallel  with 
the  upper  edge. 

Fig.  205  shows  the  arrangement  for  the  lower  hicuspids  and  molars. 
Here,  too,  the  line  of  holes  is  not  parallel  with  the  edge,  to  allow  for 

the  difference  in  distance  from  the  commis- 
sure of  the  lips  to  the  anterior  and  posterior 
holes. 

Fig.  206  shows  the  arrangement  when  the 
lower  incisors  and  canines  are  included. 
Here  the  line  of  the  apertures  is  curved. 

By  conforming  to  these  arrangements  of 

the  openings  in  the  rubber,  and  by  extending 

the  line  in  conformity  with  it,  as  well  as  by 

increasing  the  size  of  the  piece,  any  number  of  holes  may  be  made,  to 

include  any  portion  or  all  of  the  teeth  of  one-quarter  of  the  denture 

when  that  may  be  required. 

The  number  of  apertures  in  the  rubber  should  be  such  as  to  give 
easy  access  to  the  operation  and  to  permit  the  free  entrance  of  light. 
For  the  anterior  teeth  five  to  six  holes  are  necessary,  and  for  the  pos- 
terior teeth,  from  four  to  six,  as  may  be  needed  to  secure  the  above-stated 
objects.  In  general,  at  least  two  teeth  anterior  to  the  one  operated 
upon,  and  when  admissible,  the  one  posterior,  should  be  included. 


For  lower  front  teeth. 


USE  OF  THE  RUB  BE  It  DAM  195 

The  Placement  of  the  Dam. — When  the  teeth  are  not  in  firm  contact, 
or  when  their  attachments  are  flexible,  the  adjustment  of  the  dam  is 
simple.  But  when  the  teeth  are  rigid  certain  preliminary  conditions 
should  be  secured.  It  has  been  pointed  out  (Chapter  IV)  that  in  the 
preparation  of  the  teeth  for  a  series  of  operations,  they  should  be  well 
cleaned  of  any  deposits  which  may  be  upon  them  and  be  polished  on 
their  approximal  surfaces.  This  makes  easier  the  insertion  and  the 
application  of  the  rubber. 

Generally,  when  the  case  under  treatment  is  a  proximal  surface, 
the  necessary  preparatory  separation  makes  easy  the  immediate  open- 
ing of  any  interstices  near  the  operation.  In  cases  of  extreme  fixation 
of  the  teeth  a  piece  of  rubber  dam  placed  for  a  day  or  so  in  a  couple 
of  the  neighboring  spaces  makes  it  easy  to  pass  the  rubber  through  the 
margins  of  the  interstices.  The  passage  of  a  silver  tape  with  a  little 
benne  oil  or  vaselin  on  it  often  answers  as  an  equivalent  means.  In 
the  front  teeth  a  thin  wedge  inserted  just  above  a  tight  point  permits  an 
easy  entrance. 

The  preliminary  silking  of  the  adjoining  spaces,  particularly  if  the 
silk  be  coated  with  vaselin  or  its  equivalent,  also  facilitates  the  passage 
of  the  rubber,  and  for  this  purpose  soaping  the  under  surface  of  the 
rubber  adjacent  to  the  holes  is  recommended. 

At  first  the  novice  finds  difficulty  in  making  application  of  the  dam, 
but  practice  cultivates  facility.  In  general  it  is  better  to  commence  with 
the  anterior  hole  and  proceed  posteriorly  until  all  the  intended  teeth 
are  included.  Thus  for  the  left  lower  teeth  the  rubber  is  taken  with 
the  index  fingers  applied  to  the  upper  surface,  the  other  fingers  to  the 
under  surface,  and  is  grasped  near  the  hole  for  the  front  bicuspid;  the 
hole  is  extended;  the  edge  of  the  rubber  is  inserted  in  the  mesial  inter- 
stice and  is  carried  down  to  the  gum.  It  is  then  drawn  over  the  tooth 
and  passed  into  the  next  interstice  in  the  same  manner.  This  method 
is  pursued  with  each  tooth  until  all  are  included.  The  passage  of  the 
rubber  is  facilitated  by  helping  it  downward  by  the  insertion  of  floss 
silk,  which  is  held  taut,  and  with  a  firm  and  gently  sliding  movement 
the  rubber  is  conveyed  toward  the  cervix. 

When  the  most  distant  tooth  is  the  lower  third  molar,  it  is  generally 
best,  when  the  cavity  is  on  either  side  of  the  last  interstice,  to  pass  the 
jaws  of  a  dam  clamp  through  the  posterior  hole;  the  clamp  is  then  made 
to  grasp  the  tooth,  the  dam  is  conveyed  to  the  gum  by  waxed  floss  silk, 
and  the  adjustment  is  then  carried  forward  from  tooth  to  tooth.  The 
same  procedure  is  sometimes  applicable  with  short  third  molars  in 
the  upper  denture,  or  in  case  any  of  the  posterior  teeth  are  so  shaped 
as  not  to  retain  the  rubber. 

When  the  rubber  is  adjusted  over  the  teeth  the  purpose  of  the  dam 
is  effected  by  directing  the  edge  of  the  dam  under  the  free  margin  of 
the  gum.    This  is  done  by  passing  a  silk  thread  around  the  tooth,  and 


196  EXCLUSION  OF  MOISTURE 

crossing  the  ends,  when  by  a  drawing  movement  of  the  thread  it  travels 
down  the  inclined  snrface  of  the  cervix,  carrying  the  dam  with  it,  thus 
making  a  more   secure  formation  of  the  valve. 

This  method  avoids  the  needless  paining  of  the  patient  caused  In- 
pushing  the  threads  against  the  gum  with  instruments.  Whenever 
necessan,'  for  security  the  ligature  should  l)e  tied.  This  should  be 
done  to  the  teeth  on  both  sides  of  a  proximal  cavity.  It  is  neces- 
sary here  to  place  the  cervical  margin  of  the  cavity  in  full  view  and  to 
make  certain  the  exclusion  of  moisture,  which  otherwise  might  pass  the 
valve  by  capillary  attraction. 

The  ligature  should  usually  be  passed  but  once  around  the  tooth  and 
then  be  tied  with  a  surgeon's  knot,  the  place  of  the  knot  being  on  the 
outside.  When  there  is  much  strain  the  thread  may  be  passed  twice 
around  the  tooth,  but  this  should  be  avoided  as  being  more  painful  and 
as  increasing  the  bulk  of  the  ligature. 

To  prevent  the  rubber  from  displacement  by  the  movement  of  the 
cheeks  on  the  posterior  teeth  when  they  are  long,  if  after  drying  the 
surface  a  little  sandarac  or  dammar  varnish  is  applied  at  the  last  inter- 
stice the  rubber  becomes  fixed. 

In  cavities  extending  above  the  cervix,  when  a  ligature  cannot  be 
placed  above  the  cervical  border  of  the  cavity,  other  means  have  to  be 
adopted  to  obstruct  the  entrance  of  fluids.  Here  the  strait  of  rubber 
between  the  holes  should  be  much  wider  than  usual;  the  abundant  fold 
may  then  be  forced  beyond  this  margin  with  a  matrix,  when,  by  drying 
the  parts  and  by  the  deft  introduction  of  alcohol  varnish  and  suitable 
wedges,  dryness  of  the  parts  is  attained. 

The  Securement  of  the  Dam  from  Displacement. — When  the  teeth 
are  short  from  incomplete  development,  or  when  their  form  is  tapering 
from  the  gum  toward  the  occlusal  aspect,  there  is  always  a  tendency  of 
the  rubber  to  escape,  and  the  contraction  of  the  commissure  of  the  lips 
tends  to  the  displacement  of  the  dam  at  the  posterior  teeth,  the  latter 
movement  often  being  sufficient  to  overcome  the  friction  of  the  ligatures. 
When  these  difficulties  arise  a  clamp  is  required. 

Fig.  207  Fig.  208 


Dr.  Southwick'.s  clamps.  Dr.  Huey's  clamps. 

The  Clamp. — This  is  an  instrument  of  much  value  not  only  as  a 
means  of  securement  of  the  rubber,  but  as  an  adjunct  to  prevent  the 
rubber  from  obstructing  the  view.    Clamps  are  more  especially  needed 


USE  OF  THE  RUBBER  DAM 


197 


to  detain  the  rubber  on  the  moUirs  and  are  rarely  refjiiired  for  the  bicus- 
pids or  the  anterior  teeth,  since,  if  the  foregoing  directions  are  followed, 
the  necessity  for  their  use  will  but  seldom  be  presented. 

Forms  of  Clamps. — For  the  molars  various  sizes  and  shapes  of  the 
"Southwick"  and  of  the  "Huey  wisdom-tooth  clamp"  are  sufficient 
for  general  use.  In  addition  to  these,  "Palmer's  set  of  eight,"  after 
the  sharp  points  of  the  jaws  are  rounded,  will  furnish  the  requisite 
variety. 

■The  Afplicatioii  of  the  Clamp. — The  selected  clamp  is  extended  by 
the  clamp  forceps  to  enable  it  to  pass  over  the  molar.  It  is  conveyed 
to  the  middle  portion  of  the  tooth,  when  the  inner  beak  should  be 
brought  against  the  tooth  at  the  gum  margin;  then  with  this  point  as  a 
fulcrum,  the  outer  beak  is  carried  to  the  cervix  on  the  buccal  surface. 
Much  pain  may  be  avoided  in  the  employment  of  this  appliance  by 
deft  and  careful  placement.     Injury  of  the  gum  and  needless  pain  has 

Fig,  209 


Dr.  Delos  Palmer's  set  of  eight  clamps. 


frequently  been  inflicted  by  careless  use  of  force  in  the  application  of 
this  appliance.  Much  of  this  may  be  avoided  by  the  previous  ligation 
of  the  tooth,  which  will  prevent  the  tendency  of  the  clamp  to  descend 
beneath  the  gum  when  the  necks  of  the  teeth  are  much  inclined  inward. 

When  it  is  necessary  to  force  the  clamp  against  the  soft  tissues,  the 
previous  application  of  a  solution  of  cocain  will  obtund  the  tissue  and 
render  the  application  bearable. 

The  Arrangement  of  the  Dam  on  the  Face. — This  concerns  the  con- 
venience of  the  operator  and  the  comfort  of  the  patient.  To  give  easy 
access  and  permit  the  entrance  of  light,  the  rubber  is  drawn  aside  at 
each  upper  corner  by  dam  holders.  The  simpler  forms  of  these  are 
sufficient  and  are  more  convenient  than  the  more  complicated  ones  when 
triangular  pieces  of  rubber  are  employed.  In  addition  a  supporter, 
shown  at  Fig.  211,  passes  over  the  head  and  engages  at  each  end 
with  the  holder.     The  comfort  of  the  patient  is  secured  by  including  a 


]98 


EXCLl'SIOX  OF   MOISTCRE 


napkin  along  with  the  ruhher  in  the  chisps  of  the  holder.  The  excess  of 
the  rubber  at  each  side  should  be  taken  up  in  a  fold  and  secured  to  the 
napkin  by  dressing  pins.  The  suspended  part  of  the  rubber  is  kept 
taut  by  pendant  weights. 

The  application  and  arrangement  of  the  dam  becomes,  by  practice, 
a  very  simple  matter,  and  should  not  be  the  occasion  of  discomfort  or 
pain  to  the  patient. 


Fig.  210 


Fig.  211 


Design  of  Dr.  Cogswell. 


A  supporter. 


The  Use  of  Napkins. — There  are  many  instances  of  simple  cases  in 
accessible  positions  not  of  proximal  surfaces,  when  the  general  flow 
of  saliva  can  be  kept  under  control  by  the  saliva  ejector,  where  it  is  not 
necessary  to  use  a  rubber  dam.  Also  for  children,  when  the  teeth  are 
too  .short  to  permit  the  correct  application  of  the  dam,  it  is  necessary  to 
find  other  means  to  control  the  moisture.  Here  the  reliance  is  upon 
napkins,  and  with  them  much  skill  may  be  displayed  by  deft  operators. 
For  this  purpose  the  napkin  should  not  be  over  eight  inches  square. 
The  manner  of  folding  is  to  carry  two  adjacent  edges  to  the  diagonal 
of  the  napkin,  and  then  fold  again  in  like  manner;  by  this  plan  the 
folds  are  held  in  place. 

To  apply  a  napkin  to  the  upper  right  sifh',  the  point  is  taken  between 
the  left  index  finger  and  the  thumb,  the  broad  end  being  held  at  the 
same  time  by  the  right  hand.  The  lip  near  the  right  commissure  is 
everted,  the  point  is  in.serted  here,  and  by  the  taut  action  of  the  left 
hand,  the  napkin  is  next  laid  between  the  gum  and  the  lip.  It  is  then 
carried  backward  until  it  reaches  the  duct  of  Steno,  when  the  left 
index  finger  is  applied  to  maintain  the  compression  at  this  latter  point. 
The  free  end  of  the  napkin  lies  upon  the  lower  lip.  For  the  left  side 
the  action  is  the  same  by  the  reversal  of  the  hands. 

For  the  lower  teeth  the  application  dift'ers  by  commencing  for  each 


USE  OF  THE  RUBBER  DAM 


199 


side  at  the  upper  canine  of  that  side.  When  the  duct  of  Steno  is  reached, 
a  fold  is  made  to  elfect  the  compression  of  the  orifice  of  the  duct,  then 
the  napkin  is  laid  between  the  cheek  and  the  lower  teeth,  and  kept  in 
position  by  the  left  index  finger,  a  mirror,  or  a  check-holder. 

An  important  preliminary  to  the  application  of  a  napkin  to  these 
positions  is  that  the  saliva  ejector  be  first  placed  in  action  and  that  the 
surfaces  of  the  gum  and  cheek  be  wiped  to  dryness,  to  cause  the  napkin 
to  cling  to  the  surface.  If  the  surfaces  are  covered  with  mucus  and 
at  the  same  time  are  wetted  with  saliva,  the  napkin  easily  becomes 
displaced. 


Fig.  212 


Aseptic  Napkins. — For  simple  procedures,  such  as  dressings,  making 
examinations,  putting  in  temporary  stoppings,  and  small  occlusal  fillings, 
the  recently  introduced  aseptic  napkins  are  very  useful.  They  are 
folded  into  triangular  shape.  The  evolution  into  this  form  is  shown 
by  Fig.  212. 


Fig.  213 


Fig.  214 


In  the  completed  form  these  may  be  placed  in  any  convenient  manner 
to  assist  in  protecting  many  easy  cases  from  the  encroachment  of  saliva. 
Used  in  connection  with  absorbent  and  non-absorbent  rolls  they  furnish 
much  facility,  and  do  not  encumber  the  mouth  or  cause  distress.  Fig. 
213  shows  the  manner  of  applying  the  folded  aseptic  napkin,  where 
it  is  held  in  place  by  an  Ivory  clamp.  In  this  and  similar  cases  a  short 
piece  of  non-absorbent  roll  may  be  included  with  advantage  at  the  part 
opposite  the  duct  of  Steno,  which  by  the  pressure  will  occlude  this  duct. 


200  EXCLUSION  OF  MOISTURE 

Similar  means  may  be  followed  with  the  lower  teeth  by  placing 
non-absorbent  rolls  as  appears  in  Fig.  214.  When  in  connection  with  an 
absorbent  roll  to  occliule  the  parotid  duct,  uncomplicated  occlusal  cases 
are  carried  on  with  facility.  Hence  it  will  appear  the  field  of  work  may 
be  upon  any  of  the  teeth  within  the  limits  of  the  rolls. 

Nausea. — The  contact  of  the  rubber  dam  with  the  tongue  and  the  con- 
tiguous parts,  the  presence  of  napkins,  and  the  touch  of  the  hngers  to  the 
oral  surfaces  frequently  excite  nausea.  With  some  persons  this  kind  of 
distress  is  extreme  and  produces  simulation  of  faintness  and  nervousness. 
This  condition  may  generally  be  relieved  by  the  use  of  aqua  camphora, 
a  few  drams  being  used  as  a  gargle  to  the  mouth  and  throat.  When 
indications  of  faintness  appear  a  dram  may  be  swallowed  with  immediate 
benefit. 

In  case  excessive  nausea  is  occasioned  by  the  contact  of  the  appli- 
ances with  the  tongue  or  palate,  these  surfaces  may  be  painted  with 
tincture  of  camphor.  Spasmodic  coughing,  not  infrequent  with  nervous 
persons,  yields  to  the  same  treatment.  Camphor  appears  to  relieve  in 
these  instances  by  its  antispasmodic  power,  and  it  is  stated  to  have  also 
a  specific  action  upon  the  eighth  pair  of  nerves. 

Nervousness  coming  on  during  any  of  the  operations  upon  the  teeth 
may  as  easily  and  in  the  same  manner  be  avoided.  It  will  l)e  observed 
that  in  neither  of  these  conditions  are  the  first  signs  of  approaching 
syncope  apparent,  viz.,  sighing  respiration,  pallor,  and  clammy  perspira- 
tion of  the  face. 

A  condition  somewhat  simulating  approaching  syncope,  sometimes 
appears  in  connection  with  the  use  of  the  rubber  dam,  due  to  partially 
suspended  respiration,  which  is  caused  not  so  much  by  the  obstruction 
of  the  mouth  as  by  the  unpleasant  sensations  occasioned  by  the  appli- 
cation and  presence  of  the  dam.  I'his  may  at  once  be  overcome  by 
requesting  the  patient  to  breathe  deeply  through  the  nose. 


CHAPTER    IX 

THE  OPERATION  OF  FILLINCJ  CAVITIES  WITH  ME^FALLIC 
FOILS  AND  THEIR  SEVERAL  MODIFICATIONS 

By  EDWIN  T.  DARBY,  D.D.S.,  M.D. 

In  the  selection  of  a  filling  material  the  operator  should  consider  the 
character  of  the  secretions  of  the  oral  cavity,  the  position  of  the  tooth 
to  be  filled,  the  extent  of  the  diseased  area,  the  physical  structure  of  the 
tooth,  and  the  strength  of  the  cavity  walls.  A  filling  material  must 
possess  certain  inherent  qualifications,  the  most  important  of  which  are 
adaptability,  indestructibility,  non-conductivity,  hardness,  absence  of 
shrinkage,  harmony  of  color,  and  ease  of  manipulation.  All  of  these 
are  not  to  be  realized  in  any  one  material,  and  yet  some  of  the  more 
important  are  to  be  found  in  a  single  metal  or  in  a  combination  of  metals. 

Lead,  formerly  used  as  a  tooth-filling  material,  possesses  the  quality 
of  softness  and  is  easy  of  adaptation,  but  is  readily  oxidized  when 
exposed  to  the  air  or  the  secretions  of  the  mouth.  Likewise  tin  pos- 
sesses characteristics,  such,  for  instance,  as  ductility  and  softness,  low 
conducting  power,  and  the  ease  with  which  it  may  be  manipulated, 
which  place  it  in  the  front  rank  as  a  preservative  of  carious  teeth,  but 
it  is  inharmonious  in  color,  and  its  very  softness,  which  is  so  desirable 
in  manipulation,  is  an  obstacle  to  its  use  upon  surfaces  where  there 
is  much  attrition.  The  zinc  phosphates,  which  are  composed  of  zinc 
oxid  and  phosphoric  acid  in  solution,  form  a  combination  which  at 
first  attracted  the  favorable  attention  of  the  dental  surgeon  as  possible 
substitutes  for  metallic  foil  fillings.  They  possess,  owing  to  their  plas- 
ticity, ease  of  manipulation,  harmony  of  color,  comparative  non-con- 
ductivity, and  absence  of  shrinkage,  many  desirable  qualities,  but  are 
lacking  in  one  essential  qualification,  namely,  indestructibility. 

The  silicate  cements,  which  are  attracting  so  much  attention  at  the 
present  time,  have  some  superior  qualities  over  the  zinc  phosphate 
cement  in  that  they  have  more  lasting  qualities,  but  they  are  brittle  and 
the  edge  strength  is  poor. 

GOLD 

Gold,  which  has  been  used  for  about  a  century,  has  fulfilled  in  a  more 
marked  degree  than  any  other  material  or  combination  of  materials  the 
requirements  sought  for  in  a  filling  for  carious  teeth.     It  has  one  or  two 

(201) 


202  THE  OPERATION  OF  FILLING  CAVITIES 

objectionable  features,  such  as  high  conductivity  of  heat  and  electricity, 
and  inharmonious  color. 

Too  much  stress  cannot  be  laid  upon  the  (juestion  of  its  purity  if  the 
best  results  are  to  be  obtained  from  its  use.  While  it  is  claimed  by 
manufacturers  of  dental  gold  foil  that  their  products  are  absolutely  free 
from  alloy,  it  is  nevertheless  true  that  but  few  specimens  of  dental  foil 
show  a  fineness  above  999.  If  this  standard  were  always  attained  the 
operator  would  have  little  cause  for  complaint.  So  small  a  percentage 
of  allovas  1  in  1000  would  not  materially  affect  the  working  (|ualities 
of  the  product,  but  when  this  is  increased  to  4  or  (J  parts  per  1000  it 
manifests  itself  by  harshness  and  intractability  under  the  instrument. 

Great  care  should  be  exercised  in  the  prejxiration  of  the  foil,  since 
so  much  depends  upon  its  purity  and  cleanliness.  For  a  detailed 
description  of  the  process  of  manufacture,  from  ingot  to  the  beaten 
and  annealed  foil,  the  reader  is  referred  to  an  article  by  a  practical 
foil  maker.  ^ 

In  former  times  the  dental  surgeon  was  restricted  to  one  form 
of  gold  for  filling.  This  was  foil  ranging  in  thiclmess  from  4  to  10 
grains  to  the  leaf,  but  as  the  requirements  of  the  operator  broadened 
the  art  of  manufacture  increased,  and  new  preparations  were  offered, 
until  today  the  most  fastidious  can  find  such  as  will  please  his  fancy: 
foils  ranging  in  weight  from  4  to  120  grains  to  the  leaf;  cylinders  of 
various  sizes  and  composed  of  non-cohesive  and  semi-cohesive  foil; 
cohesive  blocks  prepared  for  use;  rolled  gold,  varying  in  thickness  from 
No.  30  to  120,  and  crystal  gold  possessing  great  cohesive  properties. 
These  are  the  more  important  forms  in  which  gold  is  offered  the  operator 
at  the  present  time. 

Before  entering  upon  a  description  of  the  classes  of  cases  where  each 
of  these  seems  best  adapted,  it  may  be  well  to  describe  somewhat  in 
detail  the  peculiar  qualities  which  each  form  of  gold  presents  when 
subjected  to  clinical  use. 

Soft  or  Non-cohesive  Foil. — Prior  to  1S54,  when  Dr.  Robert  Arthur 
discovered  and  promulgated  the  desirability  of  cohesive  foil  in  certain 
cases,  the  operator  used  gold  which  possessed  very  low  cohesive  proper- 
ties. Used  as  it  then  was,  in  the  form  of  large  rope,  tape,  or  as  cylinders, 
the  property  of  cohesion  would  have  been  a  serious  objection,  since  there 
would  be  constant  danger  of  the  mass  clogging  and  bridging  in  the 
cavity,  and  the  cause  of  many  unfilled  places  along  the  cavity  walls. 

The  terms  soft  and  hard,  when  used  to  designate  the  kind  of  gold,  are 
misleading,  since  all  gold  foil  prepared  from  pure  gold  or  gold  that  is 
nearly  pure  possesses  great  softness  under  the  instrument.  The  distin- 
guishing characteristics  between  the  two  kinds  of  gold  are  the  inability 
to  make  a  certain  kind  of  foil  cohesive  when  exposed  to  a  reasonable 

'  American  System  of  Dentistry,  vol.  iii,  p.  839. 


GOLD  203 

degree  of  heat,  and  the  abiUty  to  render  another  make  of  equal  purity 
cohesive  by  the  apphcation  of  a  siniihir  degree  of  heat.  It  has  been 
claimed  by  some  manufacturers  of  dental  gold  foils  that  they  are  able 
to  produce  from  the  same  ingot  samples  of  non-cohesive,  semi-cohesive, 
and  extra-cohesive  gold,  attaining  these  physical  properties  of  the  mate- 
rial vt^ithout  alloying  with  other  metals.  This  has  led  to  the  belief 
that,  since  absolutely  pure  gold  possesses  inherent  cohesive  properties, 
some  metallic  salt  or  other  foreign  substance  has  been  deposited  upon 
the  surface  of  the  leaf  of  non-cohesive  foil  which  has  the  power  of  pre- 
venting the  union  of  the  surfaces  of  the  foil  when  contact  is  sought. 
It  has  been  surmised  that  a  thin  film  of  iron  has  been  deposited  upon 
the  surfaces  of  the  leaf  of  non-cohesive  foil,  for  the  reason  that  if  a 
leaf  of  such  foil  be  melted  into  a  globule,  it  presents  a  reddish-brown 
appearance,  which  is  not  true  of  the  leaf  of  cohesive  foil  when  melted 
as  above. 

Much  of  the  so-called  non-cohesive  foil  offered  for  sale  is  not,  strictly 
speaking,  of  this  variety,  as  the  application  of  moderate  heat  will  render 
it  quite  cohesive.  It  possesses  the  softness  peculiar  to  pure  gold  foil, 
but  it  should  not  be  classed  with  the  variety  which  does  not  weld  with 
other  particles  of  the  same  metal  except  when  subjected  to  great  heat. 

It  has  been  claimed  by  some  that  non-cohesive  foil  has  no  place  in 
dental  practice — that  any  tooth  which  can  be  filled  with  gold  may  be 
filled  with  cohesive  foil.  This  statement  may  be  true  in  the  main,  but 
it  is  also  true  that  many  teeth  having  strong  cavity  walls  can  be  just  as 
well  filled  where  a  large  portion  of  the  filling  is  made  with  non-cohesive 
foil,  and  with  a  great  saving  of  time.  Adaptation,  not  hardness,  con- 
stitutes the  saving  quality  in  cavity  filling. 

As  most  non-cohesive  foil  is  prepared  in  the  form  of  sheets  and  is 
placed  in  books  containing  one-eighth  of  an  ounce,  the  operator  is  com- 
pelled to  prepare  it  in  some  form  suitable  for  introduction  to  the  cavity. 
The  size  and  shape  of  the  cavity  will  be  some  guide  as  to  the  best  method 
of  preparing  the  gold.  The  narrow  tape,  the  mat,  the  tightly  rolled 
cylinder,  and  the  roll  or  rope  are  the  forms  best  adapted  for  the  use  of 
non-cohesive  gold  foil. 

The  tajpe  is  best  made  by  taking  one-half  or  one-third  of  a  leaf  of 
No.  4  or  No.  5  foil,  laying  it  upon  a  table  napkin  of  medium  size  folded 
square  as  it  comes  from  the  laundry;  the  napkin  is  then  taken  in  the 
palm  of  the  left  hand,  and  the  foil  spatula  is  placed  in  the  middle  of 
the  piece  of  foil;  the  hand  is  then  closed  tightly,  thus  folding  the 
napkin,  likewise  the  foil,  upon  the  sides  of  the  spatula.  This  process 
is  repeated  until  the  tape  is  one-eighth  or  one-sixteenth  inch  in  width 
(Fig.  215). 

If  mats  are  required,  the  foil  may  be  folded  twice  or  three  times  and 
then  folded  lengthwise  upon  itself  until  mats  of  any  thickness  are  pro- 
duced, as  shown  in  Fig.  216. 


204 


THE  OPERATION  OF  FILLINO  CAVITIES 


When  non-cohesive  ci/Iinderft  are  desired,  it  is  better  for  the  operator 
to  make  them  rather  than  depend  upon  the  rearly-made  ones  as  prepared 
by  the  manufacturer,  since  these  are  usually  loosely  rolled  and  more  or 
less  cohesive.  The  tape  is  quickly  made  into  the  cylinder  by  rolling  it 
upon  a  five-sided  broach  to  the  desired  size.  The  depth  of  the  cavity 
is  a  guide  to  the  width  of  the  tape,  and  the  width  of  the  tape  determines 


Fig.  215 


Fig.  216 


Tapes  of  gold  foil. 


Mats  of  gold  foil. 


the  length  of  the  cylinder.  These  should  be  somewhat  longer  than  the 
depth  of  the  cavity.  The  manner  of  introducing  and  condensing  will 
be  described  later  when  special  cases  are  under  consideration. 

The  roll,  or  "rope,"  as  it  was  formerly  called,  is  made  in  the  following 
way:  A  leaf  or  half  leaf  or  a  third  of  a  leaf  of  foil  is  rolled  between  the 
thumb  and  finger  until  a  roll  of  moderate  density  is  obtained.  As  foil 
is  contaminated  by  contact  with  the  moisture  and  surface  impurities  of 
the  hands,  it  is  better  to  avoid  such  contact  as  much  as  possible.     This 


Fic.  217 


Devices  for  rolling  gold  foil. 


can  be  completely  attained  by  rolling  it  upon  the  little  device  shown  in 
Fig.  217.  Any  operator  can  make  one  of  these  by  taking  two  pieces  olF 
thin  board,  such,  for  instance,  as  the  lid  of  a  cigar  box,  and  fastening 
to  the  two  pieces  with  glue  a  piece  of  white  kid  about  eight  inches  in 
length,  and  in  width  equal  to  the  sheet  of  foil.  Two  little  drawer 
knobs  of  ebony  or  other  hard  wood  should  be  inserted  into  the  centre 


GOLD  205 

of  each  of  the  pieces  of  board.  Tliese  act  the  part  of  handles  for 
holdini^'  the  appliance.  The  gold  is  first  placed  upon  the  kid  strip 
between  the  lower  edges  of  the  covered  boards,  and  by  bringing  the 
two  surfaces  of  the  kid  in  contact  and  rubbing  them  together  with  a 
to-and-fro  motion  the  foil  is  rolled  into  a  roughly  made  cylinder.  The 
cylinder  is  then  transferred  to  the  board  and  further  rolled  until  it  is 
reduced  to  the  desired  diameter.  The  undressed  surface  of  the  kid 
should  be  the  one  upon  which  the  gold  is  rolled.  Ropes  thus  made 
may  be  cut  in  lengths  to  suit  the  size  of  the  cavity  to  be  filled,  and,  as 
gold  thus  prepared  has  great  softness  and  ease  of  adaptation,  it  may 
be  inserted  in  quite  large  pieces  if  plenty  of  condensing  force  be  applied 
to  it. 

Cohesive  Gold  Foil. — All  gold  which  h?s  been  refined  by  any  of  the 
ordinary  methods  and  is  in  a  pure  state  may  be  said  to  be  cohesive. 
Nor  is  absolute  freedom  from  alloy  an  absolute  necessity.  It  has  been 
shown  that  softness  is  dependent  upon  purity,  but  a  foil  may  contain 
quite  a  percentage  of  silver,  copper,  palladium,  or  zinc,  and  yet  its 
cohesion  may  not  be  impaired.  It  may  also  be  alloyed  or  combined 
with  platinum  and  not  lose  its  cohesive  properties.  It  is,  however, 
desirable  that  cohesive  gold  be  pure,  since  the  smallest  peicentage  of 
alloy  destroys  its  softness. 

When  two  sheets  or  laminae  of  freshly  annealed  foil  are  brought  into 
contact  and  slight  pressure  is  applied,  they  form  a  permanent  union  and 
are  practically  inseparable.  It  is  this  property  in  gold  to  w^hich  the 
term  cohesive  has  been  applied.  But  this  property  is  soon  lost  by  the 
occlusion  of  gases  or  impurities  of  any  kind  which  may  be  deposited 
upon  the  surface  of  the  gold.^ 

Experiments  have  demonstrated  the  fact  that  if  the  gold  be  sub- 
jected to  the  fumes  of  ammonia,  hydrogen,  hydrogen  carbid,  hydrogen 
phosphid,  or  sulphurous  acid  gas,  its  cohesive  property  is  (juickly 
destroyed,  but  this  property  may  be  restored  by  heat,  except  in  the  case 
of  sulphur  or  phosphorous  fumes.  Hence  the  importance  of  excluding 
the  gold  as  much  as  possible  from  the  atmosphere,  especially  during  the 
winter  months,  when  gases  arising  from  the  combustion  of  coal  are  most 
liable  to  be  present  in  the  operating-room. 

Dr.  Black  has  shown  that  ammoniacal  gas  has  the  power  to  prevent 
the  deleterious  influence  of  other  gases,  and  recommends  that  the  foil 
be  subjected  to  the  influence  of  carbonate  of  ammonia  by  keeping  it  in 
a  drawer  with  a  bottle  of  that  salt. 

The  advantages  of  cohesive  foil  cannot  be  overestimated.  With  its 
introduction,  in  1855,  began  a  new  era  in  the  possibilities  of  saving 
carious  teeth.  Operations  which  were  deemed  impossible  by  the  use  of 
non-cohesive  foil  were  made  comparatively  easy  by  the  intelligent  use 

^  G.  V.  Black,  Dental  Cosmos,  vol.  xvii,  p,  138. 


206  THE  OPERATION  OF  FILLING  CAVITIES 

of  cohesive  foil.  The  restoration  of  broken-down  or  badly  decayed 
teeth  became  the  common  practice  in  the  hands  of  the  skilful,  and 
modern  methods  of  practice,  coupled  with  intclli<i;ciit  use  of  this  form  of 
j:jold,  have  made  it  possible  for  the  operator  of  modern  times  to  do  that 
which  the  earlier  practitioner  deemed  impossible. 

The  be();inner,  however,  must  not  lose  si^dit  of  the  fact  that  cohesive 
foil  cannot  be  worked  after  the  same  methods  as  non-cohesive  foil.  To 
use  cohesive  foil  in  the  form  of  mats  or  cylinders  or  in  tightly  rolled 
ropes  would  mean  inevital)le  failure  in  adaptation.  The  very  j)roperty 
which  renders  it  valuable  in  the  restoration  of  broken-down  teeth  and  in 
surfacing  is  the  one  which  would  condemn  it  if  used  carelessly  in  the 
interior  of  inaccessible  cavities.  Non-cohesive  gold  may  be  introduced 
into  a  well-shaped  cavity  in  large  masses,  and  because  of  its  softness 
and  ease  of  adaptation  may  be  made  to  touch  all  points  of  the  cavity 
walls  if  persistent  pressure  be  applied.  On  the  contrary,  cohesive  foil 
should  be  introduced  in  small  pieces,  the  first  of  which  should  be  well 
anchored  in  a  retaining  pit  or  groove  and  each  subsequent  piece 
welded  thereto. 

There  are  several  modes  of  preparing  the  beaten  cohesive  gold  foil 
for  the  cavity,  and  good  results  are  obtained  by  either  of  the  following 
methods : 

A  loosely  rolled  rope  made  of  a  quarter  sheet  of  No.  4  or  5  foil  may 
be  cut  into  lengths  varying  from  one-eighth  to  one  inch,  and  after 
annealing,  carried  to  the  cavity  upon  the  point  of  the  plugging  instru- 
ment. Or  a  leaf  may  be  folded  with  a  spatula  four  times,  making  a 
broad  ribbon,  which  may  be  cut  either  lengthwise  or  crosswise  of 
the  ribbon  in  pieces  one-sixteenth  or  one-eighth  of  an  inch  in  width 
(Fig.  218).  This  is  a  very  convenient  manner  of  working  cohesive  gold. 
Or  the  heavier  foil  up  to  No.  20  or  No.  30  in  thickness  may  be  cut  in 
strips  of  a  single  thickness  and  of  the  widths  above  indicated,  and  after 
annealing  may  be  packed  into  the  cavity — the  essential  idea  being  ever 
kept  in  mind,  that  but  a  small  quantity  of  the  gold  shall  be  under  the 
instrument  at  a  given  time.  Cohesive  gold  Avhich  has  been  rolled  instead 
of  beaten  to  the  desired  thickness  is  much  prized  by  some.  It  has  been 
asserted  that  a  greater  softness  is  obtained  when  gold  has  been  thus 
prepared.  Such  gold  should  not  be  more  than  No.  20  or  No.  30  in 
thickness  to  insure  the  best  results.  It  should  be  cut  into  narrow  strips, 
and,  after  annealing,  be  folded  back  and  forth  as  rapidly  only  as  each 
previous  fold  has  been  well  condensed.  Good  results  are  only  attainable 
if  each  lamina  be  thoroughly  welded. 

The  loosely  rolled  cylinders  and  blocks  which  are  prepared  by  some 
dealers  and  offered  as  cohesive  gold  are  usually  but  slightly  cohesive, 
and  if  used  in  this  form,  without  le-annealing,  may  be  packed  in  the 
interior  of  cavities  without  danger  of  clogging;  but  if  freshly  annealed 
they  are  contraindicated,  since  there  is  more  or  less  danger  of  imperfect 


GOLD 


207 


union  of  all  particles  of  the  ^ohl.  It  is  cjuestionahle  whether  the  lar<j;er 
sizes  are  admissible  when  the  lillin^-  extends  beyond  the  cavity  walls, 
and  ^reat  solidity  is  an  essential  factor. 

Crystal  Gold. — This  form  of  ^old  was  introduced  by  Mr.  A.  J.  Watts 
in  ISoo,  and  as  prepared  at  the  present  time  is  one  of  the  best  prepara- 
tions of  cohesive  gold.  When  first  brought  out  the  method  of  manu- 
facture was  faidty,  since  it  was  difficult  or  impossible  to  rid  the  spongy 
mass  of  nitric  acid,  which  was  used  in  its  preparation,  but  since  ]\Ir. 
Watts  adopted  electrolysis  instead  of  chemical  precipitation  the  objec- 
tionable features  no  longer  exist.  Gold  thus  prepared  manifests  great 
cohesive  properties,  and  when  used  with  care,  as  beautiful  operations 
can  be  made  with  this  gold  as  with  any  form  of  cohesive  foil.     The 


Fig.  21 S 


Ribbons  and  strips 


operator  should  not  lose  sight  of  the  fact  that  the  gold  is  to  be  introduced 
into  the  cavity  in  small  quantities.  Should  failure  attend  its  use,  it 
would  doubtless  be  from  the  attempt  to  introduce  it  too  rapidly.  Gold 
of  this  variety  comes  in  bricks  and  strips  containing  one-eighth  of  an 
ounce  each,  and  is  either  torn  apart  in  irregular-shaped  pieces  or  cut  by 
means  of  a  razor  into  small  cubes.  This  gold  should  be  excluded  as 
much  as  possible  from  the  atmosphere,  and  when  used  should  be  well 
annealed,  although  when  recently  made  it  is  quite  cohesive. 

Moss  fiber  gold  is  another  form  of  crystal  gold,  and  differs  from  the 
variety  previously  described  in  that  the  crystals  seem  larger,  and  the 
mass  is  not  so  compact.  It  may  be  used  wherever  a  crystal  gold  is 
indicated. 


208  THE  OPERATION  OF  FILLING  CAVITIES 

Gold  and  Platinum. — This  form  of  gold  has  found  much  favor  with 
many  practitioners  for  the  restoration  of  incisal  edges,  or  where  for  any 
reason  great  hardness  of  surface  is  desired. 

An  ingot  or  bar  of  pure  gold  and  one  of  platinum  are  "sweated" 
together  and  then  rolled  to  the  desired  thinness,  usually  about  that  of 
No.  20  or  No.  30  foil.  It  is  then  cut  into  narrow  strips,  freshly  annealed, 
and  used  after  the  same  manner  as  heavy  foil.  The  conuningling  of 
the  platinum  with  the  gold  gives  the  filling  a  tint  more  nearly  the  shade 
of  the  tooth,  and  for  this  reason  it  is  much  used  upon  labial  surfaces  and 
in  mouths  where  the  teeth  are  much  exposed. 

Gold  thus  combined  with  platinum  is  much  more  rigid  than  gold 
alone,  and  is  contraindicated  for  making  the  bulk  of  most  fillings.  The 
best  results  are  obtained  from  it  when  the  mallet  is  used  for  its 
condensation  tliroughout. 


ANNEALING  GOLD 

After  the  manufacturer  has  reduced  the  gold  to  the  desired  thinness 
by  beating,  his  last  act  before  booking  it  is  to  heat  it;  this  is  termed 
annealing.  Gold  foil  which  has  been  recently  made  and  excluded  from 
the  atmosphere  or  certain  gases,  as  previously  mentioned,  may  present 
sufficient  cohesive  properties  to  weld  satisfactorily;  but  this  property  is 
soon  lost,  and  re-heating  becomes  necessary  if  it  is  desirable  to  get  union 
of  the  various  layers. 

Most  operators  make  use  of  an  alcohol  flame  for  annealing  gold; 
others  a  small  Bunsen  gas  burner.  Some  hold  the  piece  of  gold  to  be 
annealed  in  the  direct  flame  or  a  little  above  it;  others  place  the  gold 
upon  a  tray  of  Russia  iron,  mica,  or  platinum,  and  hold  this  in  the  flame 
of  the  lamp  or  gas  jet.  This  latter  method  is  safest,  since  there  are  apt 
to  be  impurities  in  the  flame  dependent  upon  a  charred  wick,  a  particle 
of  phosphorus  dropping  into  the  wick  from  the  burning  match,  or,  in 
the  case  of  the  gas  jet,  imperfect  combustion,  which  might  give  either 
carbon  or  sulphur  deposits  upon  the  surface  of  the  gold.  M\  or  any 
of  these  accidents  would  impair  the  working  qualities  of  the  gold. 

The  most  satisfactory  method  of  annealing  gold  is  by  the  use  of  the 
electric  annealing  tray.  Such  a  device  has  been  invented  by  Dr.  L.  E. 
Custer,  and  is  shown  in  Fig.  219.  By  this  method  the  gold  may  be 
heated  to  any  desired  degree  and  Avith  a  uniformity  not  easily  attained 
by  the  methods  generally  used.  The  working  (jualities  of  foil,  whether 
non-cohesive  or  cohesive,  are  greatly  enhanced  by  the  application  of 
heat  at  the  time  of  using.  Gold  that  is  absolutely  non-cohesive  is  made 
tougher  by  annealing  and  yet  its  softness  is  not  impaired,  while  cohesive 
gold  may  be  made  either  slightly  or  decidedly  cohesive  according  as 
much  or  little  heat  may  be  applied  to  it.     It  is  the  practice  of  many 


INTIiODUCTWN  OF  GOLD  209 

ojKM'jitors  to  use  the  f^old  hut  slii^htly  cohesive  wh(Mi  filliiif,^  cavities  sur- 
rouuded  h_y  strou^'  WJilIs,  and  th(i  gold  known  as  seuii-cohesive,  in  the 
form  of  loosely  rolled  cylinders,  is  much  used.  As  the  filling  approaches 
coni})letion  the  cylinders  are  heated  and  additional  cohesive  property 
imparted  to  them.  But  when  the  object  is  the  restoj'ation  of  cont(jur  or 
building-up  of  teeth  which  have  been  broken,  the  gold  should  be  heated 
but  little  short  of  redness  in  order  that  the  greatest  cohesive  property 
may  be  realized. 

Fig.  219 


Custer's  electric  annealing  tray. 


INTRODUCTION  OF  GOLD,  AND  THE  MANNER  OF  ADAPTING  IT 
TO  THE  WALLS  OF  THE  CAVITY 

It  has  been  shown  in  Chapter  VII  that  few  cavities  are  of  proper 
shape  for  retaining  the  filling  when  the  decay  alone  has  been  removed. 
Most  cavities  require  to  be  given  a  retentive  shape  so  that  the  filling 
shall  not  be  dislodged  during  its  introduction  or  by  mastication  or 
otherwise  after  its  completion.  In  former  times,  when  the  operator  was 
restricted  to  one  form  of  gold,  and  that  the  non-cohesive  variety,  he  was 
compelled  to  prepare  his  cavities  accordingly;  but  at  the  present  time, 
when  the  variety  is  almost  endless,  he  can  shape  his  cavity  with  a  view 
to  conserving  tooth  structure,  and  when  he  has  given  it  the  desired  shape 
he  can  select,  from  the  many,  a  special  form  of  gold  that  will  meet  his 
requirements. 

There  are  certain  principles  involved  in  the  packing  of  gold  which  must 
be  borne  in  mind,  and  the  operator  should  study  these  before  introducing 
his  filling.  The  first  of  these  is  the  application  of  force,  and  the  direction 
and  relation  of  that  force  to  the  object  to  be  attained.  If  a  given  cavity 
is  to  be  filled  with  non-cohesive  gold,  the  operator  must  take  into  consid- 
eration the  strength  of  the  cavity  walls,  and  must  determine  whether  by 
the  wedging  process  which  he  will  exercise  in  the  effort  to  adapt  the 
gold  to  the  walls  of  the  cavity  he  will  nm  the  risk  of  breaking  them. 

Non-cohesive  gold  is  usually  introduced  by  what  is  known  as  hand 
14 


210  THE  Ol'EHATIOX  OF   FILLIXd  CAVITIES 

pres.sure.  Each  layer  of  gold  is  carried  to  the  floor  and  the  walls  of 
the  cavity  by  a  process  of  wedging,  and  the  mechanical  arrangement  of 
each  piece  of  gold  should  be  such  that  no  portion  of  the  gold  can  escape 
when  the  filling  is  completed.  It  will  be  shown  later  (^n,  when  con- 
sidering the  various  types  of  cavities  to  be  filled,  that  in  small  cavities 
of  simple  shape  the  gold  prepared  in  the  form  of  tape  is  best  suited, 
whereas  in  compound  ca\ities  or  those  of  greater  size  the  gold  may  be 
introduced  in  the  form  of  compact  cylinders  or  blocks. 

When  it  is  desiral)le  to  use  a  combination  of  non-cohesive  and  cohesive 
gold,  the  former  is  generally  introduced  first  and  the  cohesive  is  incor- 
porated with  it  by  driving  or  forcing  layers  of  cohesive  into  the  non- 
cohesive.  This  is  best  effected  by  using  single  layers  of  hea\y  foil  or 
rolled  gold  of  a  thickness  efjual  to  20,  30,  or  40  grains  to  the  leaf.  If 
the  filling  is  to  be  made  of  but  one  kind  of  gold  and  that  the  cohesive 
variety,  both  hand  pressure  and  percussion  by  means  of  the  mallet 
may  advantageously  be  employed.  The  operator  who  has  learned  to 
combine  the  two  forms  of  gold  and  is  not  restricted  to  either  method 
of  packing  is  best  qualified  for  the  requirements  which  are  presented  in 
general  practice.  Perfect  adaptation  to  the  walls  may  be  effected  by 
either  method,  but  greater  celerity  and  the  attainment  of  equal  excel- 
lence may  be  readied  by  combining  the  two. 

Plugging  Instruments. — In  the  selection  of  instruments  for  packing 
gold  the  operator  should  have  a  sufficient  number  to  meet  his  every 
need.  They  should  be  of  such  a  variety  of  patterns  that  every  part  of 
ever\^  cavity,  however  remote,  can  be  reached  with  ease.  It  is  a  mis- 
taken notion  that  a  large  number  of  instruments  (if  well  selected)  is 
confusing.  The  operator  should  study  his  instruments  and  know  their 
uses  as  thoroughly  as  he  knows  the  letters  of  the  alphabet,  and  if  this 
be  done  and  they  be  arranged  in  an  orderly  manner  in  his  case,  the  con- 
fusion will  be  manifest  in  their  absence,  not  in  the  possession  of  them. 

For  packing  non-cohesive  foil  none  are  better  adapted  than  the  set 
shown  in  Fig.  220,  made  from  patterns  furnished  i)y  Dr.  B.  J,  Bing. 
This  set  should  be  supplemented  by  a  small  and  a  merlium-sized  foot- 
shaped  condenser  (Fig.  221)  for  packing  cylinders,  mats,  or  blocks 
against  the  gingival  wall. 

The  handles  of  instruments  used  for  packing  non-cohesive  foil  should 
be  of  such  size  that  they  can  be  grasped  firmly  in  the  hand.  When  made 
of  wood  they  are  light  in  weight  and  agreeable  to  touch.  Plugging 
instruments  should  have  as  few  curves  and  angles  as  is  consistent  with 
the  ability  to  reach  all  points  in  the  cavity.  As  these  are  multiplied, 
direct  force  is  sacrificed.  The  point  of  the  instrument  should  be  as 
nearly  as  possible  in  a  line  with  the  shaft.  Deviations  from  this  rule 
are  sometimes  necessary  in  order  to  reach  all  points  in  the  cavity.  Most 
plugging  instruments  have  serrated  points  and  are  used  for  all  forms  of 
gold.     As  a  rule,  these  serrations  should  be  shallow,  and  when  cohesive 


INTRODUCTION  OF  GOLD 


211 


gold  is  employed  thev  should  be  only  sufficient  to  prevent  .s]i]){)ino^, 
as  gold  that  is  (juite  cohesive  packs  as  readily  with  smooth  points  as 
with  roufifh  ones. 


Fig.  220 


13  14  15  16  17 

Dr.  Bing's  set  of  pluggers. 


18 


19 


20 


Fig.  221 


n 


It  is  not  definitely  known  when  packing  gold 
by  percussion  was  first  suggested,  but  the  idea  is 
quite  generally  accorded  to  Dr.  E.  Merrit,  of 
Pittsburg,  who  as  early  as  1S3S  used  the  hand 
mallet  for  condensing  the  surface  of  fillings 
which  had  been  introduced  by  hand  pressure. 
The  first  mallets  used  were  of  light  weight  and 
were  made  of  wood  or  i^ory.  As  the  method 
became  more  general,  heavier  mallets  were  em- 
ployed, and  those  made  of  lead,  tin,  various  al- 
loys, and  steel  found  much  favor.  Before  the  intro- 
duction of  rubber  dams  for  excluding  moisture 
one  hand  of  the  operator  was  employed  in  holding  the  napkin,  and  it 
became  necessary  to  have  an  assistant  at  hand  to  do  the  malleting. 
This  led  ingenious  minds  to  discover  some  means  of  percussion  besides 
the  hand  mallet,  and  several  spring  instruments  known  as  automatic 
pluffSfers  were  introduced.     The  Snow  and  Le^^"is,  the  Foote,  and  the 


Foot-shaped  con- 
densers. 


212  THE  Ol'EUATlON  OF  FILLING  CAVITIES 

ShIiuoii  found  greatest  favor,  and  all  of  them  were  good  of 
their  kind.  Fig.  222  shows  the  Snow  and  Lewis  automatic  mallet 
as  made  at  the  present  time.  When  pressure  is  aj)plied  to  the 
point  of  the  instrument  a  spring  is  liberated  which  throws  a  plunger 
forward  with  great  force,  which  is  expended  upon  the  gold  beneath  the 
point.  The  impacting  (luality  of  this  blow  is  not  excelled  by  any  of 
the  mechanical  devices  in  use.  It  is  so  constructed  that  a  light  or  a 
heavy  blow  can  be  given  at  will,  'i'he  operator  will  do  well  to  adjust 
the  instrument  for  light  blows  when  using  it  in  close  proximity  to  frail 
or  delicate  walls,  as  there  is  more  or  less  danger  of  fracturing  them. 

Instruments  of  this  class  are  not  well  adapted  to  packing  gold  in 
the  posterior  teeth  of  the  lower  jaw,  as  the  blow  is  delivered  at  a  more 
or  less  obtuse  angle,  and  unless  care  be  exercised  when  the  operation  is 
Hearing  completion  the  plugger  point  will  slip  from  the  surface  of  the 
filling  and  wound  the  soft  tissues. 

Another  instrument  of  this  type,  devised  by  Dr.  Frank  Abbott 
(Fig.  223),  has  a  socket  at  either  end  of  the  hand-piece,  the  one  giving 
a  pushing  and  the  other  a  pulling  blow.  The  latter  is  serviceable  for 
condensing  gold  upon  distal  surfaces. 

The  electric  mallet  is  one  of  the  most  ingenious  devices  employed 
in  dentistry.  The  first  practical  a})plication  of  electromagnetic  force 
for  dental  malleting  was  made  by  the  late  Dr.  ^Y.  (i.  A.  Bon  will.  Its 
latest  development  is  shown  in  Fig.  224,  This  instrument  has  found 
great  favor  among  dentists  for  packing  cohesi\e  gold.  Its  blows  are 
delivered  with  great  rapidity  and  with  such  force  that  great  solidity  is 
attainable.  A  pair  of  electromagnets  transforms  the  electric  current 
into  electromagnetic  force,  which  is  transmitted  to  the  hammer.  The 
electric  current  is  furnished  by  a  Bunsen  or  Partz  battery,  or  the 
controlled  current  from  a  dynamo  or  storage  battery  can  be  used  as 
the  motive  power.  The  direct  dynamo  current  of  110  volts  can  be  so 
modified  by  the  use  of  a  rheostat  that  its  use  may  be  employed,  and  the 
trouble  incident  to  keeping  a  battery  charged  avoided.  In  the  hands 
of  a  skilful  ojierator  there  could  be  nothing  l)etter  for  packing  cohesive 
gold.  The  best  results  are  obtained  by  its  use  when  the  gold  is  j)rcj)arcd 
in  thin  laminae  or  where  a  single  thickness  of  heavy  foil  or  rolled  gold  is 
employed. 

Considerable  experience  is  necessary  to  enable  the  oj)erator  to  use  this 
instrument  with  satisfaction  to  himself  and  his  ])atient.  If  the  plugger 
point  be  pressed  hard  against  the  filling,  the  blows,  which  are  delivered 
with  great  rapidity  and  force,  become  painful  and  distressing  and  there 
is  also  danger  of  chipping  the  cavity  walls.  The  better  plan  is  to  hold 
the  point  slightly  away  from  the  surface  of  the  filling  and  allow  the 
momentum  which  is  given  the  instrument  by  the  falling  armature  to 
complete  the  union  of  the  various  pieces  of  gold. 


Fir..  221 


Fm.  223 


Fig.  224 


Snow  and  Lewis  auto-         The  Abbott  mallet, 
matic  mallet. 


S.  S.  White  electric  mallet  "No.  2." 

Founded  on  the  '  'Bonwill."  0213) 


214 


THE  OPERATION  OF  FILLIXC  (AVmES 


Fig.  225 


The  engine  mallet  (Fig.  225),  known  us  the  "Jionwill  mechanical 
mallet,"  should  be  used  upon  a  cord  engine  only.  Much  of  the  dis- 
favor which  has  attended  its  use  has  been  owing  to  the  fact  that  it  has 

been  applied  to  cable  en- 
gines, and  for  which  it  is 
not  in  any  way  adapted. 
The  instrument  shown  in 
tlic  illustration  embodies 
many  improvements  in 
construction  which  have 
been  suggested  by  various 
o])erut()rs,  and  a  point  of 
relative  perfection  has  been 
reached  where  are  com- 
bined great  efficiency  with 
compactness  and  lightness 
in  handling.  It  will  be 
seen  by  the  illustration  that 
the  essential  feature  of  this 
instrument  is  a  revolving 
wheel,  having  inserted  in 
its  periphery  a  hollow 
cylindrical  steel  roller. 
This  constitutes  the  ham- 
mer. It  gives  an  "elastic" 
not  a  "dead"  blow,  as  it 
is  held  to  its  position  by 
a  stiff  steel  spring.  The 
roller  revolves  slightly  in 
its  socket  at  each  contact 
with  the  plunger.  When 
the  engine  is  run  at  ordi- 
nary speed  the  wheel  re- 
volves with  great  velocity, 
delivering  upon  the  head 
of  the  plunger  as  many  as 
fifteen  blows  per  second. 
The  force  of  the  blow 
can  be  modified  at  will 
by  an  extremely  simple 
contrivance,  as  follows: 
The  interdigitations  seen 
around  the  upper  end  of 
the  sleeve  are  held  to- 
EngiDe  mallet.  gether    by    means    of    a 


INTRODUCTION  OF  GOLD 


215 


spring  attached  to  the  sleeve.  Piilliiio-  the  sleeve  away  from  the  head 
against  the  spring,  and  revolving  it  to  the  right  or  left,  raises  or  lowers 
the  head  of  the  plunger.  Upon  releasing  the  sleeve  the  spring  at  once, 
throws  it  back  to  engage  with  the  head,  and  the  blow  is  heavier  or 
lighter,  according  to  the  direction  in  which  the  sleeve  has  been  revolved. 
The  impacting  power  of  the  blow  from  this  is  great,  and  in  the  hands 
of  an  experienced  operator  a  large  c|uantity  of  gold  can  be  condensed 
in  a  short  space  of  time.     When  cohesive  gold  foil  is  employed  smooth 

Fio.  226 

5  -CSS2 -Gsnj-fillll  — 'illiS-n 


Vameys  set. 


Chappell's  set. 


oval  points  may  be  used  with  most  satisfactory  results.  The  point 
should  not  be  pressed  hard  against  the  filling,  but  a  skimming  or  smooth- 
ing motion  given  to  the  instrument.  The  surface  of  the  filling  when 
thus  packed  has  a  polished  or  planished  appearance  as  if  done  with  a 
hand  burnisher.     Such  fillings  are  usually  of  great  density. 

There  are  other  mechanical  mallets  intended  for  use  on  the  engine 
which  have  what  is  known  as  a  "cam"  movement.  They  are  not, 
strictly  speaking,  mallets,  for  the  instrument  is  pushed  rather  than 


216 


THE  OPERATION  OF  FILLING  CAVITIES 

Fir..  227 


■        o        o  a     o     • 


driven  forward  by  an  eccentric.  The  Buckingham  and  the 
Hohiies  mallets  belong  to  this  class.  They  have  not  the  same 
steadiness  of  motion  as  the  ones  previously  described,  and  for 
this  reason,  among  others,  have  not  been  in  general  use. 

In  the  selection  ofplugc/er  points  for  power  mallets  the  operator 
will  do  well  to  confine  himself  to  those  having  more  than  one 
row  of  serrations  and  those  which  are  smooth-faced.  The 
serrations,  if  any,  should  be  extremely  shallow,  and  the  corners 
of  the  instrument  slightly  rounded.  Those  of  the  foot-shaped 
variety  are  admirably  adapted  to  power  mallets,  and  as  there 
is  a  great  variety  of  patterns  and  sizes  he  will  have  little  diffi- 
culty in  meeting  his  every  wish  in  this  particular.  A  few  points 
selected  from  the  Webb,  the  Varney,  and  the  Chappell  sets  will 
fill  all  requirements.  'J'he  accompanying  cut  (Fig.  220)  shows 
a  good  working  set  which  has  been  selected  from  the  three 
mentioned.  The  handles  of  these  instruments  are  too  small  to 
be  grasped  firmly  in  the  hand,  nor  are  they  well  adapted  for  use 
with  the  hand  mallet.  The  accompanying  set  shown  in  Fig. 
227  comprises  instruments  which  may  be  used  as  hand  pluggers 
or  in  conjunction  with  the  hand  mallet.  Many  of  them  are  in- 
tended for  hand  pressure  alone.  It  is  not  necessary  that  the 
beginner  purchase  the  entire  lot  at  the  outset,  but  it  is  thought 
that  with  this  combination  his  every  need  will  be  filled. 


FILLINGS  BY  CLASSES  217 


FILLINGS  BY  CLASSES 

Class  A:  Smooth  Surface  Cavities,  Cavities  in  the  Gingival  Third  of 
Labial,  Buccal,  and  Lingual  Surfaces  of  the  Teeth. — ^lost  oavitit^s  ii]k)ii  the 
smooth  surfaces  of  the  teeth  are  simple  in  form  in  that  they  have  four 
walls  surroundino^  them. 

There  is  some  difficulty  in  filling  such  cavities  if  the  gingival  wall  of 
the  cavity  is  above  the  gum  line,  and  a  fold  of  its  membrane  extends 
into  the  cavity.      In  such  an  event  it  is  better  to  press  the  gum  away 
with  gutta-percha  or  some  similar  substance  and  post- 
pone the  filling  with  gold  until  absorption  shall  have  i''"  '■^-^ 
taken  place,  which  in  most  instances  will  require  only 
a  few  days,  or  at  most  not  more  than  a  week  or  two. 
If  the  overhanging  gum  tissue  is  not  too  great  it  may 
be  cut  away  with  a  sharp  bistoury,  and  the  operation 
completed  at  the  same  sitting.     However,  in    most 
instances  the  rubber  dam  can   be   applied,  and  by 
means  of  a  Woodward  clamp  (Fig.  228),  held  in  posi-       woodward  damp. 
tion  throughout  the  operation  of  inserting  the  filling. 

If  the  clamp  is  not  at  hand,  the  same  thing  may  be  accomplished,  but 
with  a  little  more  effort,  by  using  a  straight  instrument,  the  end  of  which 
has  been  made  round  and  sharp  by  honing  it  on  an  Ai-kansas  oil  stone. 
The  dam  is  then  raised  well  above  the  gingival  wail  of  the  cavity  and  the 
point  of  the  instrument  pressed  well  into  the  cementum  and  held  with 
the  left  hand  throughout  the  filling  of  the  cavity. 

No  effort  should  be  made  to  force  a  ligature  above  the  gingival  border 
of  such  cavities,  for  such  a  procedure  would  not  only  wound  the  gum 
where  it  dips  low  into  the  interproximal  spaces,  but  would  be  liable  to 
set  up  an  irritation  in  the  gingivae  and  possibly  in  the  peridental  mem- 
brane, and  would  also,  in  the  nature  of  things,  be  attended  with  failure. 

It  is  always  well  when  filling  such  cavities  to  include  in  the  rubber  dam 
at  least  one  or  more  teeth  on  either  side  of  the  one  being  operated  upon. 

Cavities  of  this  order  are  usually  shallow  and  need  no  resistance  form, 
and  what  little  retention  form  they  require  is  to  be  found  in  the  point 
angles. 

If  cohesive  gold  is  used  for  starting  the  filling  (and  it  is  usually  indi- 
cated), the  point  angles  at  the  axio-mesial  and  axio-distal  walls  should 
be  deepened  into  a  convenience  or  starting  point  and  the  first  piece  of 
gold  thoroughly  fixed  therein,  after  which  the  remainder  of  the  filling 
may  be  added  without  danger  of  rocking  or  rolling  in  the  cavity.  The 
operator  should  learn  early  that  where  a  filling  is  to  be  made  of  cohesive 
gold  alone,  his  first  piece  must  be  securely  anchored;  otherwise  he  will 
be  building  upon  an  unstable  foundation  and  his  operation  will  prove  a 
failure.     If,  on  the  other  hand,  it  is  thought  best  to  start  the  filling  with 


218  THE  OPERATION  OF  FILLING  CAVITIES 

^old  thut  is  noii-coliesive,  or  witli  soft  mats,  or  cvlinders,  kiunvn  as 
semi-cohesive,  he  may  lay  a  foundation  upon  the  axial  wall,  forcing  the 
(fold  well  into  the  })oiiit  an<fles,  and,  after  partially  condeiisintf,  work 
some  cohesive  gold  into  the  mass,  completing  the  filling  with  gold  that 
has  been  freshly  annealed  and  made  quite  cohesive.  These  cavities  are 
so  exceedingly  simple  when  the  rubber  is  held  securely  ai)()ve  the  gin- 
gival wall  of  the  cavity  that  faiku'e  to  make  a  good  operation  would  be 
rare.  Nevertheless,  the  operator  must  not  overlook  the  importance  of 
j)ackiiig  his  gold  in  the  direction  of  each  of  the  four  walls,  that  it  may  be 
thoroughly  bound  into  the  cavity  by  these  walls.  Oreat  care  should  be 
exercised  not  to  batter  or  injure  the  cavo-surface  angle.  A  sharp,  well- 
defined  border  adds  materially  to  the  artistic  appearance  of  such  fillings. 
As  gold  fillings  upon  labial  surfaces  of  the  teeth  are  usually  conspicuous, 
it  is  often  well  to  fill  such  cavities  with  platinous  gold,  because  the  tint 
of  the  two  metals  in  combination  is  more  nearly  the  shade  of  the  to(jth; 
especially  is  this  true  in  teeth  of  yellowish  hue. 

While  decay  upon  the  labial  surface  of  the  incisors  and  cuspids  does 
not  often  extend  over  the  lal)io-mesial  or  labio-distal  angle  of  the  tooth, 
it  does  sometimes  happen  that  the  cavities  upon  the  proximal  surface 
of  the  teeth  extend  so  far  labially  that,  for  the  good  of  the  tooth,  the 
frail  wall  of  enamel  is  better  cut  away,  making  the  two  proximal 
cavities  confluent  with  the  one  on  the  labial  surface.  In  such  an  event, 
the  mesial  and  distal  cavities  may  be  filled  with  gold  and  a  porcelain 
inlay  inserted  in  the  labial  cavity  if  necessar^^  A  little  of  the  gold  may 
be  cut  away  in  shaping  the  cavity  for  the  inlay. 

Fig.  229  Fig.   230 


Class  B:  Cavities  in  the  Proximal  Surfaces  of  the  Incisors  and  Cuspids 
Which  Do  Not  Involve  the  Incisal  Angle. — These  are  shown  in  Figs.  229* 
and  230.  If  sj)ace  between  the  teeth  has  been  made  previously,  only  l)y 
a  mechanical  separator  at  the  time  the  cavity  is  being  prepared,  the  gold 
may  be  inserted  at  once.  It  must  be  borne  in  mind  that  all  fillings 
upon  proximal  surfaces,  wherever  located,  are  to  be  given  full  contour, 
or  made  to  touch,  at  or  near  the  point  of  original  contact.  This  is  one  of 
the  fixed  laws  of  a  creed  that  is  rigid,  and  as  reasonable  as  rigid.    Satis- 

I  niustnitions  229  to  239  are  reproduced  from  Dr.  Black's  Operative  Dentistry  and  are  used  in 
this  chapter  through  tlie  courtesy  of  the  Medico-Dental  Publishing  Company. 


FILLINGS  BY  CLASSES  219 

factory  results  can  only  be  obtained  by  havinf^  .sutHcient  space  between  the 
teeth.  The  beginner  requires  more  space  than  the  experienced  operator, 
and  even  a  little  more  than  is  actually  needed  is  far  better  than  not  enough, 
because  many  a  contact  point  has  been  cut  away  in  finishing  the  filling 
because  of  lack  of  space,  which,  if  had  at  the  time,  would  have  enabled 
the  operator  to  add  a  little  more  gold  at  the  contact  point.  Fillings  of 
this  order  should  be  made  throughout  with  cohesive  gold.  The  foil 
may  be  prepared  in  a  rope  which  has  been  made  from  one-half,  one-third, 
or  one-cjuarter  of  a  sheet  of  No.  4  or  No.  5  cohesive  foil,  and  then  cut 
into  lengths  of  one-cjuarter,  one-half,  or  even  an  inch.  It  should  be 
freshly  annealed,  preferably  in  an  electric  annealer,  and  then  laid  on  a 
tray,  covered  with  white  kid  or  something  similar,  from  which  it  may 
be  lifted  with  the  foil  carriers  or  plugger  point.  If  the  cavity  be  on  the 
distal  surface  of  the  tooth,  and  the  labial  and  lingual  angles  have  been 
cut  equally,  and  the  approach  from  the  embrasure  be  equally  good,  it 
matters  httle  which  convenience  point  is  filled  first.  Most  operators 
prefer  working  from  the  labial  approach.  To  this  end,  therefore,  the  first 
piece  of  gold  is  carried  into  the  linguo-axio-gingival  convenience  point, 
and  held  there  by  an  instrument  in  the  left  hand  until  the  gold  can  be 
gathered  into  the  angle  by  the  use  of  the  hand  plugger.  The  first  piece 
must  be  thoroughly  seated,  with  no  tendency  to  rock  or  move,  after 
which  one,  two,  or  more  small  pieces  may  be  added  to  it,  and  the  mass 
well  malleted  with  the  hand,  automatic,  or  mechanical  mallet.  It  is 
then  well  to  fill  the  opposite  convenience  point  in  labio-axio-gingival 
angle,  working  from  the  lingual  approach.  After  a  similar  amount  of 
gold  has  been  placed  in  this  angle,  a  piece  of  gold  should  be  laid  across 
from  one  angle  to  the  other  and  packed  well  against  the  gingival  wall. 
The  building  of  gold  across  this  wall  should  be  done  with  utmost  care. 
The  piece  should  not  be  so  large  that  there  will  be  any  clogging  in 
failure  to  reach  every  portion  of  the  wall.  Frequent  gentle  malleting 
is  indicated.  The  gold  should  then  be  carried  along  the  lingual  wall, 
gradually  working  toward  the  incisal  angle,  being  careful  all  the  time 
that  the  fulness  be  maintained  in  the  direction  of  the  gingival  third. 
\Mien  the  retention  point  in  the  incisal  angle  has  been  reached,  a  right- 
angle  plugger  should  be  used  to  carry  the  gold  into  that  portion  of  the 
cavity.  Unless  there  be  great  space  between  the  teeth,  this  retaining 
pit  should  be  made  and  filled  with  right-angle  instruments.  The 
effort  to  do  this  with  a  bur  in  the  engine  is  liable  to  undermine  the 
enamel,  and  to  attempt  to  fill  it  with  a  straight  instrument  or  one  nearly 
so,  and  by  mallet  force  is  liable  to  result  in  an  imperfect  operation,  if 
not  the  fracture  of  the  incisal  angle  of  the  tooth. 

^Yhen  the  incisal  angle  has  been  filled,  attention  should  be  given  to 
the  labial  wall  (Fig.  231).  The  gold  should  be  packed  toward  this 
wall  as  it  has  been  toward  each  of  the  other  walls,  ever  bearing  in 
mind  the  form  of  the  finished  fillings.     Small,  foot-shaped  pluggers  of 


220  THE  OPERATION  OF  FILLING  CAVITIES 

the  Varney  and  Webb  variety  will  be  foiiiul  useful  in  restoriiifij  tlie  eon- 
tour  of  the  filling.  The  operator  must  be  careful  throughout  the  oper- 
ation of  packing  gold,  and  esj)e(ially  when  employing  mallet  force,  that 
he  keep  a  mass  of  gold  constantly  between  his  instrument  and  the  enamel 
wall,  lest  he  chip  and  fracture  that  wall,  giving  it  a  ragged 
Fk;.  231  Qi-  serrated  appearance.     I'he  gold  should  l)e  given  great 

solidity,  otherwise  it  will  not  take  that  beautiful  finish  so 
important  in  all  gold  fillings.     There  seems  to  be  a  notion, 
more  or  less  common,   that  gold  caimot  be  made  solid 
unless  it  be  packed  exclusively  by  mallet  force.     This  is 
an  error  and  one  that  has  led  to  many  imperfectly  filled 
cavities  in  the  incisor  teeth.     More  labor  is  re(|uired  to 
condense  a  given  amount  of  gold  by  hand  j^ressure,  but 
as  great  solidity  can  be  obtained  by  it,  and  there  is  not  the  same  danger 
of  chipping  enamel  walls  when  the  hand  plugger  is  used  in  inaccessible 
portions  of  the  cavity. 

Class  C:  Cavities  in  the  Proximal  Surfaces  of  Incisors  and  Cuspids  Which 
Involve  the  Incisal  Angle. — The  method  of  introducing  the  gold  in  this 
class  of  cavities  does  not  differ  materially  from  those  just  describee], 
in  so  far  as  the  gingival  third  of  the  cavity  is  concerned.  It  does  not 
matter  whether  the  filling  be  started  in  the  linguo-axio-gingival  con- 
venience point  or  in  the  labio-axio-gingival  point.  The  ojjerator  should 
be  governed  by  circumstances.  If  his  approach  be  better  from  the 
labial  than  the  gingival  side  of  the  embrasure  he  will  preferal)ly  fill 
that  point  farthest  away  first,  and  that  will  be  the  linguo-axio-gingival. 
This  form  of  anchorage  is  applicable  to  teeth  of  broad  incisal  edges  or 
in  teeth  which  have  been  purj)osely  made  broad  upon  their  incisal 
edges  for  the  purpose  of  gaining  this  form  of  anchorage. 

After  the  two  gingival  anchorages  have  been  filled  and  the  gold  well 
malleted,  additional  pieces  of  gold  are  added,  until  the  gold  has  been 
pac-ked  across  the  gingival  wall  and  that  portion  of  the  filling  brought 
out  to  its  greatest  distal  or  mesial  fulness  or  against  the  proximating 
tooth.  The  gold  is  then  built  along  the  linguo-axial  wall,  as  shown  in 
Fig.  231,  until  the  incisal  step  is  reached;  then  along  the  pulpal  wall 
into  the  angles  which  have  been  made  by  the  inverted  cone  bur,  being 
careful  that  each  of  these  point  angles  has  been  thoroughly  filled  and 
the  gold  made  solid  therein.  When  this  has  been  accomplished,  a 
sense  of  security  may  be  felt  that  the  gold  will  not  be  dislodged.  The 
direction  of  the  plugging  instrument  must  be  constantly  in  a  general 
line  with  the  long  axis  of  the  tooth,  and  at  no  time  should  an  angle  of 
less  than  12  centigrades  be  used.  It  should  also  be  borne  in  mind  that 
the  force  should  incline  in  the  direction  of  the  wall  to  be  filled.  The 
only  way  to  accomplish  that  is  to  drive  it  in  that  direction.  Gold  is 
often  driven  away  from  rather  than  toward  the  tooth.  "When  the  filling 
has  progressed  thus  far  the  shape  of  the  tooth  may  be  restored,  working 


FILLINGS  BY  CLASSES  221 

gradually  from  the  (rinnrivul  third  toward  the  middle  and  iiicisal  third, 
ever  bearing-  in  mind  the  form  of  the  filling  at  the  point  of  contact. 
Much  of  the  final  packing  of  gold  may  be  done  with  small  foot-shaped 
pluggers.  Before  removing  the  rubber  dam,  or  even  before  a  burnisher 
has  been  used  upon  the  surface  of  the  gold,  a  careful  inspection  of  all  the 
walls  should  be  made,  to  be  sure  that  at  no  point  has  there  been  a  failure 
to  get  sufficient  gold.  Special  attention  should  be  given  to  the  incisal 
angle.  A  failure  to  fill  every  point  along  the  cavo-surface  angles  would 
result  in  early  failure  of  the  filling;  also,  great  hardness  is  needed  here; 
otherwise  the  surface  of  the  gold  will  be  liattered  by  the  opposing  tooth. 
Platinoid  gold  is  sometimes  indicated  upon  the  incisal  edge  because  of 
its  greater  hardness. 

Class  D:  Cavities  in  Proximal  Surfaces  of  Bicuspids  and  Molars. — It  will 
be  seen  by  reference  to  cuts  of  these  prepared  cavities  in  Chapter 
VII  that  there  is  great  similarity  in  the  form  of  cavities  in  the 
bicuspids  and  molars.  The  convenience  form  has  leceived  so  much 
attention  that  there  is  nothing  particularly  difficult  in  the  introduction 
of  the  gold.  If.  the  teeth  have  been  previously  separated,  or  if  a  me- 
chanical separator  is  to  be  used  for  effecting  space,  the  operation  of 
introducing  the  gold  should  follow  immediately  upon  the  excavation 
of  the  cavity. 

There  are  two  methods  of  starting  fillings  of  this  type:  The  first  is 
to  fill  the  cavity  throughout  with  cohesive  gold;  the  other,  to  use  a 
combination  of  non-cohesive  and  cohesive  gold.  We  will  describe  first 
the  method  of  filling  throughout  with  cohesive  foil.  The  preparation  of 
the  gold  for  cavities  of  this  description  does  not  dift'er  materially  from 
that  previously  described  in  proximal  cavities  of  incisors  and  cuspids. 
A  roll  made  from  one-third  or  one-half  leaf  of  gold  may  be  cut  into 
pieces  ranging  from  one-quarter  to  one  inch  in  length.  When  the  gold 
has  been  annealed,  the  first  piece  is  carried  to  either  the  bucco-axio- 
gingival  or  the  linguo-axio-gingival  point  angle,  which  has  been  deepened 
into  a  convenience  point  for  starting  the  filling.  It  matters  not  which 
of  these  points  receives  the  first  piece  of  gold,  provided  they  are  equally 
accessible.  If,  on  the  other  hand,  one  is  easier  to  reach  than  the  other, 
the  one  most  remote  or  hardest  to  reach  should  be  filled  first.  The 
mstniment  a  (Fig.  232)  in  the  left  hand  should  hold  the  gold  while  it  is 
carried  into  the  starting  point  with  a  hand  plugger  h.  This  first  piece  of 
gold  must  be  thoroughly  seated,  after  which  two  or  three  pieces  may  be 
added  to  this  and  the  same  malleted  to  place.  The  opposite  point 
(Fig.  233)  should  be  similarly  filled,  and  then  a  piece  laid  across  the  gin- 
gival wall  and  connected  with  that  in  the  tw^o-point  angles  (Fig.  234). 
Several  pieces  should  be  added  until  the  gold  has  covered  the  entire 
gingival  wall  and  has  been  built  out  nearly  or  quite  across  the  inter- 
proximal space  to  the  adjoining  tooth  (Fig.  235).  It  is  at  just  this 
point  that  so  many  failures  occur.      The  gingival  third  of  the   cavity 


222 


THE  OPERATION  OF  FILLING  CAVITIES 


must  have  special  attention.  'We  cavo-snrface  anf^Ies  must  he  tlior- 
ouglily  covered.  Special  attention  should  be  given  the  filling  mesio- 
distally.  Carry  the  gold  out  to  the  adjoining  tooth  even  though 
it  may  seem  at  the  time  that  too  much  gold  is  being  added.  Piece 
by  piece  should  be  added  until  the  occlusal  step  has  l)een  reached. 
'J'he  o])erator  .should  hold  his  plugger  at  such  an  angle  that  the 
gold  is  being  constantly  driven  against  the  buccal  and  lingual  walls  of 
the  cavity,  as  well  as  against  the  gingival.  As  soon  as  the  build- 
ing of  the  filling  has  reached  the  occlusal  step  it  is  well  to  cover  the 
pulpal  wall  and  build  back  and  forth  into  that  which  has  been  placed 
against  the  axial  wall.  If  the  central  fossa  has  been  included  in  the 
cavity  and  is  deep,  it  is  sometimes  well  to  fill  this  before  covering  the 


Fig.   232 


Fig.   233 


Fig.  234 


Fig.  235 


entire  pulpal  wall,  as  it  gives  the  operator  a  sense  of  security  lest  by  any 
means  he  dislodge  the  gold  already  inserted.  A  few  ])ieces  joined  in 
this  way  and  well  malleted  will  insure  stability.  From  this  point  onward 
attention  should  be  given  to  the  proper  contour  of  the  fillings.  If  addi- 
tional space  is  desired,  a  turn  or  two  of  the  screw  of  the  separator  may 
be  made.  It  is  better  to  have  rather  more  space  than  is  actually  needed 
than  to  find,  when  the  operation  has  been  completed,  that  not  enough 
gold  has  been  added  to  make  a  perfect  contact  point.  The  advantage 
of  thorough  malleting  at  this  point  cannot  be  overestimated.  The  gold 
should  be  solid,  not  only  upon  the  proximal  surface,  but  upon  the 
occlusal.  Any  defect  along  the  margin  means  a  leak  and  ultimately  a 
failure  of  the  filling.     Perfect  adaptation  and  great  hardness  are  two 


FILLINGS  BY  CLASSES  223 

essentials  in  all  fillinfjs  of  this  class.  The  other  method  of  startinf]^  these 
filliiit^s,  as  above  alluded  to,  is  to  fill  the  i^iii^ival  third  of  the  cavity  with 
non-cohesive  gold,  used  in  the  form  of  cylinders  or  blocks.  'I'his  method 
has  the  advantage  of  greater  rapidity  and  as  great,  or  greater,  protection 
to  the  tooth  along  its  gingival  wall.  The  writer  would  not  assert  that 
better  fillings  can  be  made  by  this  method,  but  in  the  hands  of  one  who 
has  become  skilled  in  the  use  of  non-cohesive  gold  much  time  can  be 
saved,  and  experience  has  shown  that  fillings  are  etjually  as  good  as  those 
made  throughout  of  cohesive  foil.  A  half  leaf  or  Xo.  4  non-cohesive 
foil  is  folded  into  a  tape  or  ribbon  until  its  width  is  a  little  greater  than 
the  depth  of  the  cavity  from  its  axial  wall  mesio-distally.  This  tape  is 
wound  upon  a  flat  instrument  for  an  oblong  cylinder  or  a  five-sided  broach 
for  a  round  cylinder.  It  matters  not  which,  because  the  cylinder  is 
flattened  either  before  or  after  it  is  introduced  into  the  cavity.  One 
end  of  the  cylinder  is  placed  against  the  axial  wall,  the  other  projecting 
somewhat  beyond  the  gingival  wall  into  the  inteiproximal  space.  It  is 
usually  better  to  have  this  cylinder  broad  enough  (Figs.  23(3,  237,  and 
238)  linguo-buccally  to  press  upon  these  walls  and  be  forced  into  the 


Fig.  236 


Fig.   237 


Fig.  23S 


bucco-axio-gingival  and  the  linguo-axio-gingival  angler,.  If  a  single 
cylinder  is  used,  it  should  contain  a  considerable  quantity  of  gold,  and 
after  being  matted  down  in  a  general  way  with  a  broad-faced  pluo-o-er, 
then  a  piece  of  cohesive  gold  should  be  carried  into  the  bucco-axio- 
gingival  and  the  linguo-axio-gingival  point  angles,  taking  with  it  a 
portion  of  the  cylinder  which  has  been  mashed  against  the  buccal  and 
lingual  borders  of  the  cavity.  An  instrument  in  the  left  hand  will  aid 
the  operator  in  holding  the  cylinder  in  place  until  he  has  made  it  secure 
in  the  point  angles,  as  above.  The  mallet  may  now  be  used  and  the  gold 
thoroughly  condensed  against  the  gingival  wall,  after  which  cohesive 
gold  should  be  used  to  complete  the  filling.  Another  method  of  using 
non-cohesive  gold  in  such  cavities  is  to  use  three  cylinders,  placing  one 
toward  the  buccal,  one  toward  the  lingual  wall,  and  then  one  between 
the  two  which  acts  as  a  key.  As  the  middle  one  is  forced  toward  the 
gingival  wall  the  others  are  pressed  laterally,  after  which  the  cohesive 
gold  is  inserted  as  above  described. 

^Yhen   filling   distal   cavities  of   the  class   under  consideration,   the 


224  tup:  OrERATION  of  filling  CAViriFS 

matrix  is  often  used.  It  is  thoii(,flit  by  many  to  simplify  the  starting 
of  the  filHiifij.  One  end  of  the  cylinder  rests  against  the  matrix,  the 
other  a^^ainst  the  axial  wall.  It  un()uestional)ly  does  assist  in  holding 
the  cylinder  within  the  cavity  and  makes  the  seating  of  the  filling  much 
easier.  If  the  matrix  be  made  of  thin  copper  and  securely  lashed  to 
the  tooth  with  fioss  silk  and  wedged  securely  against  the  gingival  border 
of  the  cavity,  it  does  answer  a  good  purpose  and  may  be  used  to  advan- 
tage, but  as  great  care  is  necessary  when  packing  the  gold  around  the 
cavo-surface  angles,  and  perhaps  greater  danger  of  imperfections  at  these 
points  than  when  no  matrix  has  been  employed.  In  mesial  cavities, 
the  matrix  obstructs  the  Hght  and  should  seldom  be  used,  except  when 
amalgam  or  one  of  the  plastics  is  to  be  used  as  the  filling  material. 

Special  consideration  should  be  given  to  the  maimer  of  packing  the 
gold  in  this  class  of  cavities,  and  in  fact  in  all  cavities  which  are  to  be 
filled  with  gold.  A  hap-hazard  way,  with  a  thrust  here  and  a  blow  from 
the  mallet  there,  does  not  make  fillings  of  uniform  density,  nor  does  it 
make  fillings  with  tight  margins.  After  placing  a  piece  of  gold  at  a 
certain  point,  the  wdiole  surface  of  that  piece  should  be  gone  over  with 
the  plugger  point  step  by  step,  each  move  of  the  plugger  point  being  not 
greater  than  its  own  diameter.  It  would  be  well  if  the  operator  could 
have  in  mind  an  imaginary  line  drawn  bucco-lingually  through  the 
centre  of  the  cavity  being  filled  and  from  that  central  line  direct  his  force 
axio-lingually  and  axio-buccally  (Fig.  239).  When  the  cavity  to  be  filled 
is  as  far  back  as  the  distal  surface  of  the  second  molar,  direct  access  to 
such  cavities  is  difficult,  especially  in  the  lower  teeth,  and  to  get  direct 
force  with  pluggers  of  a  single  curve  is  impossible.  Much  of  the  packing 
of  gold  in  these  cavities  must  be  done  by  hand  pressure,  or  by  the  use  of  the 
reverse  plugger  and  mallet  force.  It  is  thought  by  many  that  the  matrix 
is  indispensable  in  cavities  of  this  kind,  but  unless  great  care  be  taken, 
imperfect  margins  will  be  the  result.  If  amalgam  were  the  material 
luider  consideration,  the  matrix  would  be  most  useful  and  always  indi- 
cated. 

The  process  of  packing  gold  in  these  large  cavities,  unfavorably 
located,  is,  in  the  nature  of  things,  slow,  but  if  good  and  lasting  results 
are  obtained  by  the  use  of  gold,  each  step  in  the  operation  must  be 
painstaking  and  thorough 

Class  £ :  Small  Cavities  on  Occlusal  Surfaces  of  the  Bicuspids  and  Molars. — 
These  are  among  the  simplest  in  form  and  may  be  quickly  filled  with 
gold  of  the  non-cohesive  variety,  if  used  in  the  form  of  tape,  or  with  the 
machine-rolled  cylinders  found  in  the  dental  depots  aiifl  known  as  semi- 
cohesive.  Those  in  the  bicuspids  are  usually  regular  in  form  and  need 
no  additional  resistance  or  retention  shape.  \Mien  the  cavity  has  been 
four-fifths  filled,  cohesive  gold  should  be  used  for  surfacing,  and  if 
throughout  the  operation  mallet  force  has  been  used  freely,  a  thoroughly 
good  filling  will  be  the  result.     Cavities  of  this  character,  although  of 


F I  LI  J  N  (IS  BY  CLASSES  225 

greater  size,  are  found  in  the  iiiolurs,  iuid  niuy  he  filled  in  the  same 
general  way.  Mats  of  foil  may  be  sul)stituted  for  tape;  or,  where  the 
cavity  is  very  large,  the  gold  may  be  introduced  in  the  form  of  cylinders. 
It  not  infrecjuently  happens  that  a  large  portion  of  the  occlusal  surface 
of  a  molar  is  lost  by  decay  and  that  die  four  walls  surrounding  the  cavity 
are  strong.  Such  cavities  may  be  filled,  with  a  great  saving  of  time,  by 
the  use  of  cylinders.  Before  the  introduction  of  rubber  dam,  when  the 
dentist  was  obliged  to  control  the  saliva  by  means  of  the  napkin  alone, 
time  was  a  great  consideration,  and  cylinder  filling  was  more  generally 
practised  then  than  now.  Excellent  results  can  be  accomplished  by  this 
method,  and  it  were  well  if  the  young  men  who  are  now  entering  the 
profession  would  learn  to  use  non-cohesive  gold,  but  it  is,  better  that 
the  beginner  first  become  proficient  in  the  use  of  cohesive  gold  lest  he 
become  confused  in  his  attempt  to  learn  too  many  methods  at  the  outset. 
Cylinders  for  such  cavities  (Fig.  240)   should   be   hand-made   and  of 

Fig.  239  Fig.  240 


Occlusal  cavity  with  cylinders. 

No.  4  non-cohesive  foil.  They  should  be  long  enough  to  reach  from 
the  pulpal  wall  to  a  sixteenth  of  an  inch  above  the  occlusal  surface 
of  the  tooth.  The  first  one  should  be  placed  at  the  most  distal  point  in 
the  cavity,  then  cylinder  after  cylinder  is  placed  around  the  walls  until 
the  buccal,  Hngual,  and  mesial  walls  are  covered.  Each  one  in  its  turn 
is  pressed  against  the  walls  with  strong  wedge-shaped  instruments.  As 
often  as  room  can  be  made  in  the  centre  of  the  mass,  another  cylinder 
should  be  placed,  and  the  same  lateral  pressure  applied.  When  no  other 
cylinders,  not  even  the  smallest,  can  be  forced  into  the  filling,  the  surface 
of  the  gold  should  be  thoroughly  condensed  by  the  aid  of  the  mallet, 
and  this  repeated  until  a  very  hard  surface  has  been  secured.  This 
method  is  better  suited  to  mortise  cavities  with  flat  pulpal  walls,  and  the 
four  other  walls  parallel,  or  nearly  so. 

From  the  foregoing  classification  of  cavities  and  the  special  manner  of 
treating  each  class,  the  reader  may  infer  that  all  cavities  which  are  to  be 
found  upon  the  proximal  surfaces  of  teeth,  no  matter  what  may  be  the 
conditions  siu'rounding  them,  are  to  be  extended  buccally  and  lingually, 
gingivally  and  incisally,  initil  the  greater  portion  of  the  proximal  surface 
of  the  tooth  has  been  cut  away.  But  such  is  not  the  intention  in  every 
15 


220  THE  Ol'ERATlOX  OF   FILLlSd   CAVITIES 

cast'.  Tlu'  rule  is  to  place  all  cavity  iiiartjjiMS  on  areas  that  are  practically 
iiuiiiune  from  caries,  but  that  zone  of  immunity  is  not  the  same  in  all 
teeth,  and  it  is  for  this  reason  that  the  writer  wouhJ  depart  from  the 
habit  which  has  become  cjuite  general,  namely,  sacrificing  a  larger 
amount  of  tooth  structure  than  is  demanded  for  tlie  preservation  of  the 
tooth.  Reference  is  juade  to  the  excej)tionally  small  cavities  that  are 
sometimes  to  be  found  in  the  anterior  teeth  (^incisors  and  cuspids)  at  or 
near  the  point  of  contact.  Experience  and  observation  have  shown  that 
there  are  certain  teeth  which  have  small  j)oints  of  contact  and  open 
embrasures  in  which  the  initial  decay  is  small  and  has  been  slow  in  its 
progress,  with  no  tendency  to  spread  over  an  area  larger  than  the  head 
of  a  small  pin.  To  cut  the  entire  mesial  or  distal  surface  away  that 
the  rule  may  l)e  observed  is  wanton  destruction  of  tooth  substance, 
and  in  thousands  of  instances  uncalled  for.  The  writer  has  seen  fillings 
placed  in  these  small  cavities  which  have  lasted  fifty  years  or  more,  with 
no  recurrence  of  decay.  If  the  dentists  of  a  half-century  ago  could  fill 
such  cavities  with  non-cohesive  foil  and  make  the  tooth  good  for  a  life- 
time, surely  the  dentist  of  toduy,  who  understands  the  nature  of  caries, 
and  the  means  of  preventing  it,  who  has  grasped  the  principles  of  sus- 
ceptibility and  immunity,  and,  in  addition  thereto,  has  the  benefit  of  the 
increased  facilities  in  operating,  surely  better  results,  if  possible,  may 
reasonably  be  expected  at  his  hands.  This  is  a  j>lea  for  small  cavi- 
ties in  the  anterior  teeth,  in  which  the  structure  is  good  and  the 
embrasures  broad.  Such  cavities  may  be  shaped  in  the  same  general 
way  as  those  heretofore  described,  and  may  be  filled,  either  with  non- 
cohesive  gold,  in  the  form  of  tape,  or  with  cohesive  gold,  prepared  in 
any  form  desired;  the  lingual  and  labial  walls  left  intact,  or,  if  it  may 
seem  best,  the  lingual  angle  may  be  cut  away  and  the  approach  to  the 
cavity  be  from  the  lingual  surface 

FILLING  WITH  TIN^ 

It  is  not  definitely  known  when  tin  was  first  employed  for  filling 
carious  teeth,  but  it  has  been  used  for  at  least  a  century  and  has  found 
great  favor  with  many.  Prior  to  the  improvement  in  the  formulas  of 
dental  amalgams,  tin  was  used  more  generally  than  at  the  present  time. 

Tin  possesses  certain  inlierent  characteristics  which  make  it  valuable 
as  a  filling  material.  Among  these  are  great  malleal)ility,  non-con- 
ductivity, and  it  is  thought  by  many  to  possess  antiseptic  properties. 
But  while  it  has  desirable  cjualities,  it  has  also  some  undesirable  ones, 
such  as  .softness,  and  when  exposed  to  the  secretions  of  the  month  it 
discolors — which  facts  render  it  unfit  for  surfaces  exposed  to  great  wear 
in  the  act   of  mastication  and   upon  surfaces  exposed   to  view.       The 

I  Tlie  physical  and  clieiiiical  properties  of  tin  in  conneetion  with  its  use  a*  a  filling  material  are 
disiiissed  in  detail  in  fliapter  XI,  p.  '.iW). 


FILLING   WITH   TIN  227 

discoloration,  however,  is  confined  to  the  surface,  and  teeth  filled  with 
tin  are  not  discolored  in  conseciuence  of  its  j>resence. 

There  are  various  methods  of  preparing"  tin  for  dental  purposes. 
That  which  has  found  <2jreatest  fa\t)r  in  the  past  is  in  the  form  of  foil. 
The  tin  used  should  be  chemicailv  pure.  An  ingot  of  the  metal  is 
rolled  into  ribbon  and  then  beaten,  after  the  same  manner  as  gold  foil, 
into  sheets  of  the  desired  thickness.  As  a  rule,  it  is  not  beaten  as  thin 
as  the  former.     The  foil  best  suited  for  most  fillings  is  No.  4. 

Pure  tin,  like  pure  gold,  is  cohesive,  and  fillings  of  considerable  solidity 
can  be  made  if  the  operator  will  exercise  care  in  packing  it.  I'he  best 
results  are  obtained  by  taking  a  third  of  a  leaf  of  No.  4  foil  and  rolling 
it  into  a  loose  rope,  then  cutting  it  into  lengths  of  half  an  inch  or  less 
and  packing  each  piece  with  a  view  of  making  each  part  of  the  filling 
solid.  Some  prefer  holding  the  sheet  with  a  spatula  after  the  same 
manner  as  gold  foil,  and  then  cutting  into  narrow  tape.  Equally  good 
results  are  obtainable  by  either  method. 

A  more  rapid  but  less  satisfactory  manner  of  introducing  the  filling 
is  to  use  the  tin  in  the  form  of  cylinders,  not  relying  so  much  upon  the 
cohesive  properties  of  the  metal.  The  directions  for  using  gold  in  the 
form  of  cylinders  will  apply  equally  well  for  inserting  tin  foil. 

Shavings  of  Tin. — The  cohesive  property  of  tin  is  best  illustrated  when 
it  is  used  in  the  form  of  freshly  cut  shavings  from  a  revolving  ingot  of 
the  metal.  Any  operator  can  prepare  his  own  shavings  and  have  them 
fresh  daily  or  hourly,  if  necessary,  after  the  following  method:  Take  an 
ordinary  corundum  wheel  two  inches  in  diameter  and  one-half  inch  in 
thickness,  such  as  is  used  in  the  laboratory.  Make  a  mould  of  this  in 
sand  or  marble  dust,  then  melt  in  a  crucible  or  ladle  enough  jpure  tin  to 
fill  the  mould.  When  it  has  been  poured  and  cooled,  mount  accurately 
upon  the  mandrel  of  the  laboratorj-  lathe,  and  from  it,  with  a  sharp 
carpenter's  chisel,  turn  shavings  of  great  tenuity.  When  freshly  cut, 
and  before  oxidation  of  the  surface  has  taken  place,  by  exposure  to  the 
atmosphere  it  will  be  found  that  the  tin  coheres  with  the  same  readiness 
that  pure  gold  does.  Broken-down  teeth  can  be  built  up  by  this  method, 
or  by  means  of  it  surfaces  may  be  contoured  as  with  gold. 

The  plugging  instruments  best  adapted  for  tin  filling  are  those  having 
shallow  but  well-defined  serrations  and  points  not  too  broad.  x\s  the 
margins  are  approached,  broader  points  and  condensers  may  be  used, 
and  the  surface  should  be  well  burnished.  The  operator  must  not  lose 
sight  of  the  fact  that  while  tin  possesses  many  desirable  qualities  and  is 
easily  manipulated,  it  lacks  hardness  and  is  not  adapted  to  surfaces  where 
great  attrition  occurs.  Its  chief  value  is  found  in  its  use  upon  surfaces 
concealed  from  view  and  shielded  from  wear,  and  in  the  temporary 
teeth,  where  its  greatest  value  is  manifest. 

Tin  fillings  should  be  finished  with  the  same  care  as  gold  ones,  and 
the  same  directions  will  apply  in  all  particulars. 


228 


TUI<:  Ol'ERATlON  OF  FILLING  CAVITIES 


FINISHING  FILLINGS 

Much  of  the  beauty  and  utility  of  a  Hllin^f  (lejx'iuls  upon  the  way  it  is 
finished.  It  is  not  enough  that  it  l)e  well  made;  it  must  l)e  well  finished, 
if  the  best  results  are  to  be  attained.  All  fillings  should  contain  rather 
more  gold  than  it  is  intended  shall  remain,  and  this  for  the  purpose  of 
dressing  down  to  such  lines  as  siiail  he  both  practical  and  esthetic. 

Fillings  that  are  not  solid  and  well  condensed  throughout  their  entire 
surface  cannot  be  given  a  finc^  finish. 

After  the  last  piece  of  gold  has  been  added  and  the  whole  surface  of 
the  filling  gone  over  with  a  plugger  with  shallow  serrations  or  with  no 
serrations  at  all,  a  thorough  burnishing  with  a  l)urnisher  that  is  ahso- 
lulcly  smooth,  should  be  given  the  surface  of  the  filling.  By  this  means 
the  gold  is  made  more  compact  and  the  margins  are  sure  to  be  well 
covered.  This  does  not  mean  that  imperfect  margins  can  be  made 
good  by  a  l)urnisher,  l)ut  a  good  thorough  burnishing  brings  the  gold 
in  absolute  contact  with  the  enamel  margins. 


Fin.  241 


Plug  finishing  bur 


Fig.  242 


Wood  polishing  points. 


The  small  fillings  upon  occlusal  surfaces  (and  all  pit  and  fissure 
cavities)  are  best  dressed  down  with  finishing  burs,  as  shown  in  Fig.  241. 
They  are  finely  cut  and  leave  the  gold  with  a  more  uniform  surface  than 
when  cavity  burs  have  been  used  for  the  purpose.  The  gold  should  be 
cut  away  until  the  cavo-surface  angle  has  been  reached,  and  until  all 
overlapping  of  gold  has  been  removed.  The  occlusion  of  the  tooth  of 
the  opposite  jaw  should  be  noted,  and  if  it  strikes  unduly  upon  the  filling, 
enough  should  be  taken  from  the  surface  of  the  gold  to  prevent  it.  When 
a  uniform  surface  has  been  given  to  the  gold,  a  suitable  wood  point, 
as  shown  in  Fig.  242,  should  be  mounted  in  an  engine  mandril  made 
for  that  purpose  and  the  point  dipped  first  in  water  and  then  in  fine 
pumice  powder  and  the  surface  nicely  smoothed.  After  which  a  round- 
end  burnisher  may  be  used,  if  the  operator  desires  a  polished  surface, 
although  it  adds  nothing  to  either  the  beauty  or  the  utility  of  the  filling. 

When  fillings  cover  a  larger  portion  of  the  occlusal  surface,  the  cutting 
of  the  gold  may  be  done  with  corundum  or  carborundum  ])oints  an<l 
wheels,  which,  if    kept    constantly  wet,    cut    more    ra])i(lly    than    burs 


FINISiriNG  FILLINGS 


229 


and  C'iUiso  less  lioatin^  and  less  discomfort  to  the  patient.  These  are 
shown  in  Fiy.  248,  and  are  of  many  patterns,  and  adniiraMy  adapted  for 
the  j)nrpose  intended.  Those  made  of  fine  cornndnm  and  shellac,  or 
coriindnm  and  vnicaiiized  rnhher,  are  more  desirable  than  the  coarse 
ones,  which  are  liable  to  grind  away  the  cavity  margins  l)ecanse  of  the 
ra[)i(lity  with  which  they  cut. 

Fillings  nf)on  labial  and  buccal  surfaces  should  be  dressed  down  with 
fine  stones,  such  as  the  Hindostan,  or  any  variety  that  has  fine  grit, 
until  the  outline  of  the  cavity  is  reached.  Any  overlapping  of  gold  upon 
these  surfaces  gives  a  ragged  appearance  to  the  filling  and  detracts 
nuich  froni  its  beauty.  Care  should  also  be  exercised  in  giving  the 
filling  the  same  degree  of  convexity  that  the  tooth  formerly  had — in  other 
words,  the  filling  should  accurately  restore  the  lost  anatomical  contour 
of  the  tooth. 

Fig.  243 


Corundum  points. 


Fig.  244 


Hindostan  pointb. 


\Mien  sufficient  gold  has  been  removed  the  surface  should  be  nicely 
smoothed  with  revolving  wood  points,  charged  with  pumice  powder 
and  water,  or  a  paste  made  of  pumice  and  glycerin,  after  which  the 
final  finish  may  be  made  with  flour  of  pumice,  chalk,  or  oxid  of  tin, 
used  by  means  of  a  revolving  disk  or  wheel  of  felt,  leather,  or  rubber. 
As  fillings  upon  the  labial  surface  are  more  or  less  conspicuous  at  best, 
it  is  better  not  to  give  them  a  burnished  surface.  The  "dead"  or 
satin-like  finish  w^hich  is  left  by  the  flour  of  pumice  is  usually  preferred. 

Fillings  upon  proximal  surfaces  are  more  difficult  to  finish,  and  too 
great  care  cannot  be  bestow-ed  upon  them.  An  operator  is  often  judged 
by  the  finish  that  he  gives  his  proximal  fillings,  and  justly  so,  as  no 
class  of  fillings  requires  a  higher  degree  of  skill  in  the  finishing. 

In  olden  times,  when  no  effort  w^as  made  to  restore  the  natural  contour 
of  the  tooth,  fillings  w^ere  made  flat,  and  a  file  w-as  about  the  only  instru- 
ment required  in  the  finishing  of  such  fillings;  but  the  day  of  flat  fillings 
has  passed,  and  the  separating  and  finishing  files  of  our  fathers  have  little 
use  in  the  cabinet  of  the  present-day  dentist.     The  whole  methr)d  of 


230 


THE   OI'ERATIOS   OF   FILL/Xd  CAVITIES 


finishiiifT  fillini,'s  upon  proximal  surtiiccs  has  chaiif^ed,  and  a  new  line  of 
iiKstruiueiits  suited  to  this  method  has  l)eeii  exoKcd.  'i'lierc  is  of  neces- 
sity more  or  less  overlaj)])in^'  of  ^^old  in  the  insertion  of  a  HMin<f,  and  the 
removal  of  all  excess  is  as  important  as  any  other  j)art  of  tiie  operation. 
For  this  purpose  a  variety  of  instruments  is  sup{)lied.      In  the  selection  of 


Ti...  245 


\/ 


16     17      18     19     20    21     22    23    24    25    26    27 
P'inishing  files  and  knives. 


32 


Fig.  246 


la 


CurveH  finishing  files. 


these  the  operator  should  bear  in  mind  that  he  has  a  contact  point  to  ])re- 
serve,  and  he  .should  avoid  the  u.se  of  such  instruments  as  may  cut  away 
the  thing  of  greatest  importance,  and  the  one  most  liable  to  be  destroyed- 
To  this  end,  separating  files  are  practically  to  be  eliminated,  but  in  their 
stead  gold  trimmers  of  various  patterns  are  to  be  used.     In  Fig.  24")  are 


riMSiiixc  FiLLixas  231 

illustrated  soiuo  of  those  most  iiscfiil.  'I'lie  i>iiii>iviil  wall  is  nrciierally  the 
one  to  receive  attention  first,  and  it'  the  conditions  are  such  that  the 
separator  and  rui)l)er  dam  can  be  left  in  place  until  the  gold  which  over- 
laps at  the  gingival  borders  has  been  trimmed  away  it  will  add  much  to 
the  ease  of  finishing  that  portion  of  the  filling.  It  is  well  in  all  instances 
to  retain  the  separator  as  long  as  it  can  be  done  without  interfering  with 
one's  ease  of  manipulation,  because  it  is  often  desirable  to  lift  the  teeth 
apart  a  little  for  the  purpose  of  passing  thin  finishing  strips  between, 
although,  as  a  rule,  it  is  better  to  pass  nothing  between  the  points  of 
contact,  or  what  is  to  be  the  point  of  contact,  until  nearly  the  last 
thing.  The  knives  and  finishing  files  shown  in  Fig.  245  should  be 
used  for  cutting  away  any  overlapping  gold  at  the  gingival  wall  of 
the  filling;  also  for  dressing  down  the  lingual  and  buccal  borders. 
A  finishing  strip  may  be  threaded  through  the  interproximal  space 
above  the  proposed  point  of  contact  and  worked  back  and  forth. 
Sometimes  as  many  as  a  half-dozen  pieces  should  be  used  in  getting  the 
gold  down  to  the  walls,  but  it  should  be  understood  that  these  finishing- 
strips  are  not  to  be  passed  back  and  forth  from  the  occlusal  surface, 
and  that  their  use  at  this  stage  is  to  be  confined  to  die  gingival  third  of 
the  embrasure.  Attention  may  now  be  given  to  the  lingual  and  buccal 
margins.  If  the  filling  extends  well  toward  the  lingual  and  buccal  angle 
(and  it  is  to  be  presumed  that  it  does)  a  disk  of  corundum  may  be  used 
very  cautiously  for  cutting  down  the  greater  portion  of  the  overplus  gold, 
but  in  the  hands  of  a  beginner  it  is  safer  to  confine  one's  self  to  the  hand 
files  and  trimmers.  The  same  may  be  said  of  the  sandpaper  disk  if  used 
too  freely.  The  one  point  above  all  others  is  to  avoid  cutting  away  the 
contour  which  has  been  laboriously  made,  and  so  destroy  the  contact 
point,  which  is  of  vital  importance  in  the  comfort  of  the  patient  and  the 
future  welfare  of  the  tooth.  Under  the  most  favorable  conditions,  the 
finishing  of  fillings  in  the  proximal  surfaces  of  the  bicuspids  and  molars 
is  slow,  often  consuming  as  much  time  as  the  insertion  of  the  filling,  but 
when  done  with  care  and  the  result  which  has  been  attained  it  is  well 
worth  the  time  and  effort  expended.  Attention  should  now  be  given 
to  the  proximo-occlusal  angle  and  the  occlusal  surface.  At  this  point 
stones,  revolving  in  the  handpiece  of  the  engine,  may  be  used,  but  they 
should  be  so  shaped  that  they  will  not  by  any  possibility  cut  away  the 
gold  unduly  from  the  proximo-occlusal  angle.  When  the  gingival  third 
of  the  filling  has  been  finished  and  the  contact  point  preserved,  the  rubber 
dam  may  be  removed,  and  the  further  dressing  down  of  the  occlusal  and 
proximo-occlusal  surfaces  done  with  a  wetwheel,  which  lessens  the  friction, 
and  consequently  the  heat,  which  is  often  distressing  when  using  burs  or 
wheels  of  any  kind  in  a  dry  state.  Special  attention  should  now  be  given 
to  the  articulation  of  the  filling  in  occlusion  with  the  teeth  of  the  oppo- 
site jaw.  If  the  contact  be  with  the  gold,  it  should  be  cut  away  until  the 
patient  notices  no  undue  pressure  upon  any  portion  of  the  filling.     A  filling 


2:^2  THE  OPERATION  OF  llLLIXd  CAVITIES 

jiisl  a.  littU"  too  Full  is  iiiij)l(!iisant  to  tli(;  })ati('iit;  oik;  inuc/i  too  full  is  a. 
cause  of  (liiii<;'er  to  the  filling  and  ,siirroiiii(liii(,f  walls,  and  possibly  to  tlie 
piilj)  or  poric'cmentiiiii.  Before  the  final  snioothin^,'  of  the  fillini,''  is  don(^ 
with  fine  powders,  one  last  attention  should  }iv.  vr'wvn  to  what  will  he  the 
future  point  of  contact.  It  is  presumed  that  uj)  to  this  time  every  other 
portion  of  the  fillint]j  has  heen  dressed  into  final  shape,  and  it  is  possible 
to  do  all  of  that  with  the  trinuners  and  other  means  provided;  then,  as  a 
final  touch,  before  using  the  buffing  wheels,  a  strip  charged  with  fine 
buckhorn  or  silex  mav  be  passed  a  few  times  over  the  contact  ])oint, 
and  from  that  moment  nothing  more  than  a  smooth  burnish(u*  should 
touch  it.  If,  however,  the  separator  has  lifted  the  teeth  apart  suffi- 
ciently, and  the  operator  is  assured  that  he  has  space  to  spare,  he  may 
pass  back  and  forth  between  the  teeth  a  piece  of  thin  linen  tape,  first 
made  wet  and  then  charged  with  some  fine  polishing  powder,  such  as 
chalk,  oxid  of  tin,  or  buckhorn.  When  this  has  been  done,  and  the 
occlusal  portion  has  received  the  same  careful  treatment,  the  filling  may 
be  considered  finished.  Burnishing  adds  nothing  to  its  appearance  or 
utility,  and  if  in  a  position  to  show,  only  makes  it  more  glaring  and 
manifest.  The  same  general  treatment  in  the  matter  of  finishing  fillings 
upon  proximal  surfaces  of  the  incisors  and  cuspids  obtains  and  a  special 
description  here  is  unnecessary. 


REPAIRING  FILLINGS 

Fillings  somewhat  defective  are  often  susceptible  of  repair.  The 
defect  may  sometimes  be  apparent  in  die  finishing;  at  other  times  it 
is  the  result  of  subsequent  caries,  and  at  still  other  times  the  result  of  a 
fracture  of  the  enamel  along  the  border  of  the  filling. 

The  nature  of  the  defect  and  the  condition  of  the  remaining  filling 
must  be  taken  into  consideration  before  an  effort  to  repair  is  undertaken. 

When  the  defect  is  due  to  insufficient  gold  at  any  point  in  the  filling 
more  gold  may  be  added.  It  is  well  to  first  cut  out  a  portion  of  the 
filling,  making  a  distinct  cavity  of  retentive  shape.  Cohesive  gold  is 
usually  best  suited  to  the  purpose;  crystal  gold  often  serves  well  in  the 
repair  of  such  defects. 

If  the  filling  has  been  thoroughly  condensed  and  the  mass  is  solid 
there  is  little  difficulty  in  adding  more  gold  to  it,  provided  the  surface 
be  clean.  If  it  has  been  w^et  with  saliva,  the  surface  of  the  gold  must  be 
made  not  only  dry,  but  clean.  It  is  well  to  wipe  it  wdth  a  pellet  of 
cotton  or  paper  saturated  with  absolute  alcohol  or  ether,  after  which 
the  filling  should  be  scraped  with  a  suitable  instrument.  If  the  filling 
be  of  considerable  size  and  well  anchored,  shallow  retaining  points  may 
be  drilled  into  it,  which  will  make  an  additional  hold  for  the  gold  w'hich 
is  to  be  added.     Defects  which  arise  from  subsefpient  caries  are  perha})S 


HKi'Aiiiixd  i<'ilijn(;h  233 

\\\{)rc.  fr(U(Uont  in  ])r()xim;il  siirrac'(;.s  at  or  lu^ar  tlui  ^iii^nvul  mHr<^iii. 
'riios(^  borders  wxv.  Niiliionihle  j)oint.s  for  (Ik;  recurronce  of  caries,  .ind 
iiii])erf(M'(  a(l;q)t<i.lioii  is  not  infre(|ii('iitly  tlic  (Ictenniniii^-  cause  of  the 
beginning;  of  such  dcciiy. 

To  effect  a  successful  repair  in  sucli  localities  ample  space  should  be 
obtained,  especially  so  if  the  repair  is  to  be  made  with  ^old. 

If  the  decay  has  not  extended  beneath  the  fillinf>',  and  sufficient 
space  has  been  obtained,  there  is  no  greater  difficulty  in  making  a  suc- 
cessful repair  than  in  filling  a  simple  cavity  similarly  located.  If  the 
operator  is  skilled  in  the  use  of  non-cohesive  gold,  he  will  do  well  to 
prepare  his  foil  in  the  form  of  narrow  tape,  and  work  it  into  the  cavity 
foki  after  fold,  allowing  the  loops  to  extend  somewhat  above  the  walls 
of  the  cavity.  When  the  cavity  has  been  completely  filled  the  protrud- 
ing folds  may  be  well  condensed  and  the  filling  finished  in  the  usual 
way;  or  the  repair  may  be  made  with  cohesive  gold,  the  first  piece 
having  been  made  fast  in  a  groove  or  retaining  point. 

Such  repairs  are  often  required  in  the  bicuspids  and  molars,  and 
large  fillings  otherwise  good  are  saved  by  a  successful  repair  at  the 
cervix.  The  plastics  are  sometimes  indicated  in  this  class  of  cases, 
provided  they  be  not  so  near  the  anterior  part  of  the  mouth  as  to  be 
unsightly.  Gutta-percha  often  serves  a  good  purpose  here,  but  in  some 
mouths  undergoes  decomposition  and  is  less  reliable  than  gold.  The 
oxyphosphates  are  contraindicated  because  of  their  liability  to  wash 
away  after  a  few  months.  Amalgams  are  more  frequently  used,  and 
nearly  always  serve  well  when  thus  employed;  but  unfortunately  the 
contact  with  gold  produces  discoloration,  and  an  unsightly  filling  is  the 
result.  Whenever  gold  and  amalgam  are  brought  in  contiact  in  the 
same  tooth,  if  the  surface  of  each  is  exposed  to  the  fluids  of  the  mouth, 
the  amalgam  is  almost  sure  to  turn  quite  black.  The  discoloration  of 
the  surface  of  the  alloy  does  not  lessen  its  value  as  a  preserver  of  the 
tooth,  but  its  unsightliness  is  often  too  great  to  be  tolerated;  neverthe- 
less, utility  enters  so  largely  into  the  equation  that  the  operator  feels 
justified  in  using  the  alloy,  because  with  it  he  feels  sure  of  making  a  better 
repair.  After  the  alloy  has  hardened  it  should  be  nicely  dressed  down 
and  all  overlapping  of  the  material  at  the  gum  margin  removed,  when  it 
should  be  smoothed  and  polished  with  the  same  care  that  other  fillings 
receive. 

Fracture  of  one  or  more  of  the  cavity  walls  is  a  common  accident, 
and  one  which  may  be  repaired  if  the  filling  has  been  securely  anchored 
in  portions  of  the  tooth  not  involved  in  the  fracture.  Such  accidents 
sometimes  befall  bicuspids  and  molars,  especially  the  bicuspids,  where 
fillings  have  been  inserted  in  each  proxinial  surface,  the  two  meeting 
upon  the  occlusal  surface.  The  buccal  wall  is  sometimes  the  one  broken 
away,  sometimes  the  lingual.  In  either  case  the  ability  to  successfully 
repair  depends  upon  the  stability  of  the  proximal  fillings  and  the  anchor- 


2)54  THE  OPERATION  OF  11  I.LI \(!  CWITIK^ 

jigc  which  can  he  ()l)taiiic(l  at  the  (;-iii<;ival  wall  and  in  tin;  exposcni 
lilliiiti's.  'I'o  restore  witii  liold  a  hiiccal  ciisj)  or  the  entire  buccal  surface 
of  a  hicuspid  nii^dit  necessitate  a  sliow  of  ^^oid  which  would  he  objection- 
able; and  a  better  plan  would  be  to  engraft  a  porcelain  facinii;  or  an 
entire  porcelain  crown;  whereas  such  a  restoration  on  the  lingiuU  sur- 
face would  not  be  oj)en  to  the  same  objections.  Cohesive  (^old  alone  is 
Indicated  for  repairs  of  this  kind.  Watts'  c-rystal  gold  when  used  in 
cases  of  this  description  has  been  most  satisfactory. 

If  the  fracture  extends  above  the  margin  of  the  gum  the  operation 
is  much  more  difficult  because  of  the  danger  from  a  flow  of  blood,  and 
the  additional  difficulty  of  getting  die  rubber  dam  above  the  border 
of  the  fractured  surface.  This  may  be  accom])Iished  by  filling  for  a 
few  weeks  with  gutta-percha,  when  there  will  W.  recession  of  the  gum 
caused  by  the  pressure  of  the  gutta-percha  upon  it.  When  a  similar 
fracture  occurs  in  a  molar,  if  the  fractured  surface  does  not  encroach 
upon  the  pulp,  and  will  admit  of  drilling  retaining  points  without  danger 
to  the  pulp,  there  is  no  difficulty  in  restoring  the  broken  portion  with 
cohesive  gold.  Mack's  screws  are  sometimes  indicated  in  cases  of  this 
kind,  since  strong  anchorage  can  be  secured  in  this  way  without  much 
loss  of  tooth  substance. 

Fracture  of  the  incisal  angle  of  the  anterior  teeth  is  often  a  serious 
accident,  because  of  the  difficulty  of  repair  and  the  unsightly  display 
of  gold  when  it  has  been  accomplished. 

Large  fillings  situated  upon  the  proximal  surfaces  of  the  incisors  but 
not  extending  to  the  cutting  edge,  yet  near  enough  to  weaken  the  enamel 
overhanging,  are  especially  liable  to  need  repairs.  The  corner  of  the 
tooth  breaks  aw^ay,  leaving  the  surface  of  the  gold  exposed,  and  the  only 
hold  the  filling  has  is  at  the  gingival  border.  In  order  to  secure  retaining 
hold  for  additional  gold  the  operator  must  be  careful  not  to  displace  the 
original  filling.  A  wooden  wedge  should  be  inserted  betw^een  the  teeth 
and  pressed  home  with  sufficient  force  to  hold  the  filling  securely  in 
place  during  the  operation  of  repair.  Sometimes  a  retaining  point  can 
be  made  laterally  into  the  sound  dentin,  or,  by  cutting  a  little  channel 
through  to  the  lingual  surface  and  then  deepening  the  channel  at  its 
extremity  with  a  round  bur,  a  secure  anchorage  may  be  had  for  the 
fresh  gold. 

Great  care  should  be  exercised  in  packing  the  gold,  lest  by  inadver- 
tence the  instrument  should  slip  and  push  the  original  filling  from  its 
position.  Fractured  surfaces  should  receive  prompt  attention,  for  if  left 
for  a  period  of  time  disintegration  of  the  dentin  will  set  in  and  the  caries 
may  extend  beneath  the  filling  and  thus  jeopardize  or  ruin  the  most 
thorough  work. 


CHAPTER    X 
USE  OF  THE  MATRIX  IN  FILLING  OPEUATIOXS 

By  WILLIAM  CRENSHAW,  D.D.S. 

The  matrix,  as  originally  suggested  and  employed,  was  used  exclu- 
sively between  the  molars  and  bicuspids,  and  consisted  of  curved  pieces 
of  thin  metal  of  various  kinds,  which  were  braced  with  wooden  wedges 
from  one  tooth  to  the  other;  but  now  the  matrix  has  been  adapted  to  other 
teeth  and  other  forms  of  cavities,  as  will  appear  in  the  further  develoj)- 
ment  of  this  subject.  All  forms  of  cavities  occurring  on  molars,  bicus- 
pids, and  incisors,  standing  alone  or  together,  excepting  those  cavities 
located  in  the  occlusal  surfaces  of  the  first-mentioned  class,  and  in  the 
cutting  edges  and  corners  of  the  latter,  are  now  subject  to  the  use  of  the 
matrix  as  an  aid  in  filling  them. 

The  large  and  difficult  filling  operations  encountered  between  the 
molars  and  bicuspids,  which  in  past  decades  so  taxed  the  skill  and  vitality 
of  the  dentist,  have  been  by  various  forms  of  device  rendered  easier  of 
execution  and  more  permanent  and  perfect  in  character. 

IMatrices  have  been  used  more  or  less  in  one  form  or  another  for  the 
past  fifty  years,  and  some  crude  forms  even  longer.  Dr.  Louis  Jack  gave 
the  profession  thirty  years  ago  the  first  practical  idea  and  demonstration 
of  the  matrix  and  its  possibilities,  and  his  effort,  more  than  all  that  had 
gone  before,  gave  shape  and  impetus  to  the  development  of  this  important 
device. 

GENERAL  CONSIDERATIONS 

The  limitations,  no  less  than  the  possibilities,  of  the  matrix  are  im- 
portant to  understand,  because,  used  indiscretely,  in  locations  which  the 
judgment  should  forbid  or  in  locations  where  it  would  be  perfectly  in 
place  but  for  the  unsuitable  nature  of  the  material  employed,  more  harm 
than  good  may  result  from  its  use.  To  be  able,  therefore,  to  discern  the 
proper  class  and  location  of  cavities  for  the  reception  of  the  fillings, 
together  with  a  knowledge  of  adapting  the  filling  materials  to  the  case 
in  hand,  are  some  of  the  requirements  and  demands  on  the  operator  who 
essays  to  use  matrices. 

The  matrix  should  possess  as  fully  as  possible  the  qualities  of  adapt- 
ability and  fixedness  to  the  teeth,  at  the  same  time  provide  for  contouring 
and  for  leaving  the  teeth  in  proper  position,  and  preserving  the  proper 

(235) 


236  USE  OF  THE  MATRIX   J\  FILIJSC  Ol'KRATIOSS 

interproximal  space.  J''iir(lier  desideratM  are  (liat  the  matrix  shall  i)e 
resistant  enough  to  stand  the  pressure  of  condensing  i^old  against  it, 
suseeptihle  at  the  same  time  of  hein^'  shaped  into  whatever  f(jrm  needed, 
and  caj)al)le  of  l)ein<r  removed  from  between  the  teeth  witiiout  destroyin*^ 
the  form  of  the  fillint;  after  that  has  been  completed. 

The  material  of  which  the  matrix  is  made  depends  somewhat  on  the 
location  and  class  of  the  cavity  to  be  filled. 

In  many  of  the  operations  occurring  between  molars  and  bicuspids, 
particularly  in  the  instances  where  only  one  tooth  is  decayed  and  only 
slightly  so,  slips  of  (ierman  silver  or  steel  (30  to  40  gauge)  may  be  inter- 
posed and  used.  In  the  instances  where  gold  is  to  be  the  filling,  and  the 
cavity  is  of  large  size,  the  metals  above  mentioned,  silver  and  gold  plate, 
but  of  heavier  gauge,  and  other  substances  may  be  employed.  But  in 
the  event  of  the  matrix  band  having  to  bear  heavy  tension,  which  tests  the 
strength  of  it,  as  in  the  loop  or  band  variety  or  any  duplex  form  which 
separates  the  teeth,  either  decarbonized  steel  or  phosphor-bronze,  the  ten- 
sile strength  of  which  is  equal  to  or  beyond  that  of  steel,  should  be  u.sed. 
Steel  is  somewhat  unsatisfactory,  because  if  bent  often  at  one  place  it 
breaks,  and  it  does  not  hold  polish  or  plating  well.  .  Phosphor-bronze 
not  only  polishes  and  holds  plating  well,  and  does  not  corrode,  but  solders 
readily  to  gold,  silver,  German  silver,  steel,  copper,  and  brass,  and  does 
not  soften  or  amalgamate  with  the  mercury  employed  in  amalgam  alloys. 

The  matrix  band  should  be  closely  adapted  around  the  margin  of  the 
tooth  cavity,  and  the  cavity  floor  and  walls  coming  up  to  the  band 
should  form  as  nearly  as  possible  right  angles  with  the  band.  This  rule 
followed,  with  the  employment  of  proper  forms  of  instruments,  will  be 
found  to  insure  well-condensed  margins,  and  as  full  a  contour  as  ordin- 
arily belongs  to  the  tooth  of  its  class;  and,  in  those  instances  where  it  is 
desirable,  greater  contour  than  belongs  to  the  tooth  may  be  produced. 

Those  devices  which  when  assembled  are  practically  in  one  pit^ce,  and 
admit  of  easy  application  and  steady  fixedness  on  the  teeth,  with  as  little 
of  obstructing  parts  as  possible,  are  the  ones  with  which  the  operator 
will  ordinarily  accomplish  best  results.  The  bands  should  not  purposely 
stand  away  from  the  tooth.  This  is  impracticable  even  if  it  were  desir- 
able, as  there  are  no  means  for  holding  the  band  away  from  the  tooth  and 
at  the  same  time  having  it  secure  from  slipping  and  working  loose  under 
the  operation  of  the  filling.  Occasionally  in  cavities  occurring  on  the 
mesial  side  of  upper  first  and  second  molars,  and  more  frequently  on  both 
the  mesial  and  distal  sides  of  upper  first  l)icuspifls  extending  well  under 
the  gum,  we  encounter  the  concavity  occasioned  by  the  bifurcation  of 
the  roots,  when  of  necessity  the  band  stands  off  from  the  depression. 
The  filling,  however,  whether  of  gold  or  tin  foil,  is  not  better  condensed 
at  this  point  for  that  reason. 

The  failures  made  with  the  matrix  result  (piite  fre(|uently  from  the 
selection  of  a  wrong  material.     "^Fake,  for  instance,  any  of  tiie  proximal 


GENERAL  C0N8I DEUATIOSS  237 

surfaces  of  the  molars  or  bicuspids  in  wliich  the  cavity  extends  beyond 
the  margin  of  the  enamel,  presenting  ideal  conditions  for  the  employment 
of  the  matrix;  prepare  these  cavities  after  approved  methods,  applv  the 
matrix,  and  fill  with  any  form  of  cohesive  gold,  and  we  have  a  fillinc- 
beautiful  in  appearance,  but  more  treacherous  than  beautiful,  and  one 
which  will  develop  recurrent  decay  along  the  cervical  margin  sooner  than 
would  result  from  the  employment  of  any  other  filling  material  placed 
in  the  permanent  list. 

It  will  not  matter  what  form  of  cohesive  gold  is  employed,  if  heat 
sufficient  to  change  its  molecular  arrangement  has  been  applied  in  anneal- 
ing the  gold,  it  is  practically  impossible  to  adapt  it,  unaccompanied  by 
linings,  so  as  to  secure  moisture-proof  joints,  and  therefore  permanent 
results.  Because,  first,  the  tooth  does  not  afford  the  resistance  necessary 
to  reduce  the  crystals  of  gold  into  adaptable  laminae,  and  we  have  the 
crystalline  gold  resting  on  fibrous  structure  in  the  cementum  and  dentin, 
which  together  prevent  the  making  of  moisture-proof  joints.  Therefore, 
this  state  of  affairs,  aided  either  by  the  creeping  in  of  fluid  at  the  base  of 
the  filling  from  the  canaliculi  and  lacunae,  or  drawing  in  external  moisture 
by  capillary  attraction  from  without,  permits  of  recurrent  decay.  With 
cohesive  gold,  the  result  would  be  ultimately  the  same,  with  or  without 
the  matrix;  although  the  work  would,  should  at  least,  be  better  executed 
without  it.  But  with  the  cavity  well  prepared,  and  the  matrix  securel}' 
adjusted,  the  operation  is  inviting  in  appearance,  and  the  operator  is  led 
into  a  snare  and  delusion  when  he  essays  to  fill  these  points  with  cohesive 
gold  exclusively. 

The  objection  here  raised  to  cohesive  gold  does  not  apply  to  the  same 
extent  in  adapting  it  to  enamel  walls,  because  in  this  tissue  we  have  an 
absence  of  nerve  fibers,  and  a  greatly  denser  substance  against  which  to 
adapt  the  gold.  While  it  is  impossible  to  adapt  cohesive  gold  to  tooth 
structures  so  as  to  stop  out  moisture  permanently,  for  the  reason  pointed 
out,  there  is  that  difference  in  the  histological  make-up  of  the  tissue  of 
cementum  and  dentin  and  enamel  which  explains  the  fact  of  cohesive 
gold  being  better  adapted  to  enamel,  and  can  be  made  to  better  prevent 
the  leaking  of  moisture  than  in  cementum  margins.  Again,  decay  cannot 
be  so  rapid  in  enamel  margins,  because  of  its  inherent  strength  and 
resistance,  due  in  part  to  the  absence  of  nerve  fibers  and  to  its  greater 
density  and  hardness. 

The  propaganda  of  Prof.  Henry  S.  Chase — namely,  that  in  propor- 
tion as  teeth  need  saving  gold  is  the  worst  material  with  which  to  do  it — 
is  true  in  its  application  to  cohesive  gold,  particularly  in  cementum  and 
dentin  margins  in  connection  with  the  matrix.  But  substitute  non- 
crystalline or  soft  gold  in  these  margins,  and  we  pass  from  the  worst 
possil)le  work  done  with  gold,  and  made  even  worse  by  the  employment 
of  the  matrix,  to  that  which  has  proved  the  best  possible — at  least  up  to 
the  present  time. 


238        l:se  of  the  matuix  is  fjllj.xg  ui'EUatioss 

Cohesive  <i't)l(l  is  at  its  West  in  open  eavities  with  stronjij  enamel  mar- 
gins, and  is  profitably  employed  in  cervico-occlusal  fillings  in  conneetion 
with  soft  gold  and  matrices  to  cap  over  the  proximal  wall  of  soft  gold. 
Cohesive  gold,  on  the  other  hand,  is  at  its  worst  in  connection  with  mat- 
rices when  used  at  the  cervical  margins,  particularly  when  the  margin 
is  located  in  cementum  or  dentin,  l)ecause  of  the  physical  difficulties 
encountered  in  the  adaptation  of  it,  and  the  perishable  nature  of  the 
margins  on  which  it  is  laid. 

Again,  in  the  employment  of  a  carelessly  formulated  and  compounded 
amalgam  alloy  packed  into  these  cavities  eml)raced  by  a  matrix,  depend- 
ing too  much  on  the  matrix,  as  is  the  tendency,  we  have  another  instance 
in  which  the  inefficiency  of  this  device  is  made  to  appear. 

It  should  be  made  a  rule  of  practice  in  employing  the  matrix  to  regard 
it  simply  as  a  mechanical  device,  the  object  of  which  is  to  simplify  com- 
pound and  other  difficult  cavities;  and  not  to  depend  on  it  to  make  good 
any  of  the  essentials  of  the  filling  material.  With  this  idea  in  view,  and 
fortified  by  a  knowledge  of  the  essential  characteristics  of  materials  rather 
than  matrices,  we  shall  know  where  and  when  to  employ  them.  The 
filling  materials,  too,  must  possess  constancy  of  form,  and  susceptibility  to 
that  perfect  adaptation  which  shall  prevent  the  drawing  in  of  moisture  by 
capillary  attraction,  the  result  of  which  would  be  recurrent  decay.  An 
understanding  of  these  characteristics  is  indispensable  to  the  permanence 
of  filling  operations  anywhere  and  everywhere,  and  by  whatever  method 
performed,  and  when  they  are  thus  understood,  combined  with  the 
advantages  aft'orded  in  the  use  of  the  matrix,  the  operator  will  accomplish 
his  best  results.  The  matrix  should  be  used,  therefore,  for  the  piu'pose 
of  simplifying  the  cavity,  and  never  allowed  to  lead  into  the  use  of  a 
treacherous  and  questionable  material. 

The  matrix  is  valuable  in  all  those  cavities  of  extreme  decay  involving 
the  disto-occlusal,  the  mesio-occlusal,  the  bucco-ocdusal,  the  disto-bucco, 
the  mesio-bucco,  and  the  disto-linjjuo  and  mesio-lino-uo  occlusal  surfaces 
of  molars  and  bicuspids.  In  many  instances  the  entire  corners  may  be 
restored,  as  is  intimated  and  included  in  the  disto-bucco  and  mesio-bucco, 
the  disto-linguo-  and  mesio-linguo-occlusal  surfaces.  No  method  yet 
devised  for  filling  these  teeth  is  so  satisfactory  or  productive  of  such 
results  as  when  tiie  matrix  is  employed,  as  it  aids  the  a(laj)tation  of  the 
material  definitely  and  exactly  in  j)osition.  Its  chief  advantage  is  in 
having  brought  a  cavity  of  compound  and  complex  nature  into  simple 
form,  and  so  contributing  to  the  mastery  of  the  material  that  perfect 
adaptation  and  condensation  is  secured. 

A  comparison  (^f  results  at  the  cervical  margin  between  fillings  made 
of  soft  gold  and  those  of  the  cohesive  variety  shows  in  so  marked  a  degree 
in  favor  of  the  soft,  even  in  operations  where  the  matrix  has  not  been 
used,  that  when  this  device  is  employed  it  places  the  standard  of  excel- 
lence of  soft-gold  work  far  al>ove  that  of  the  cohesive. 


CAVITY  I'liEI'AHATJON  FOli  MATIilX    W'OHK  2:^9 

With  (lie  advaiitamvs  thus  accruiim',  soft  y;()l(l  in  the  fonn  of  cushions 
or  cyhndcrs  may  he  perfectly  aihipted  at  the  cervical  aspect  and  as  far  up 
the  wall  as  desired,  cappini>;  over  with  a  slab  of  cohesive  which,  when 
anchored  in  the  occlusal  surface,  makes  a  handsome  and  lasting'  operation. 

Another  treatment  of  these  cavities  is  to  place  tin  cylinders  or  cush- 
ions, which  may  he  made  by  fol(lini>'  the  cylinders  uj)on  themselves,  and 
adapt  at  tlie  cervical  maroin  and  up  the  cei'vico-occlusal  wall  to  the  top 
of  the  step  u.  Fig.  247,  completing  with  the  slab  of  cohesive  gold  or  of 
amalgam  for  the  remainder  of  the  filling.  (See  Fig.  251.)  The  soft 
gold  and  the  tin  are  practically  the  same  in  adaptation,  due  to  the  fact 
that  in  their  manufacture  the  molecular  arrangement  is  destroyed  and 
becomes  structureless,  by  which  a  closer  and  more  perfect  adaptation  is 
possible.  The  matrix  enables  the  operator  to  take  advantage  of  this 
important  quality;  and  without  thus  simplifying  the  cavity,  it  would 
be  quite  impossible  to  confine,  control,  and  condense  these  materials,  and 
secure  adequate  solidity  and  adaptation  to  margins. 

The  use  of  the  matrix,  therefore,  not  only  enables  the  operator  to 
place  soft  gold  in  a  satisfactory  manner  at  the  points  where  it  serves  best, 
but  also  cohesive  gold  where  it  is  best  adapted — namely,  at  enamel  mar- 
gins, and  in  that  portion  of  the  filling  where  it  is  most  easily  and  perfectly 
adapted.  Again,  cohesive  gold  is  placed  in  matrix  work  at  that  point 
where  it  best  resists  the  attrition  and  stress  of  chewing,  and  the  lateral 
wear  between  the  teeth. 

Still  another  treatment  of  these  cavities  in  connection  with  the  matrix 
is  with  amalgam  alloy. 

Assuming  that  the  same  care  and  pains  have  been  taken  with  the 
preparation  of  the  cavity  for  the  amalgam  as  for  the  gold,  the  simplifying 
of  it  by  the  use  of  the  matrix  enables  the  operator  to  secure  greater 
solidity  and  correspondingly  better  adaptation  to  the  walls  of  the  cavity. 
This  material,  used  in  connection  with  the  matrix  and  cavity  lining, 
places  amalgam  alloy  on  a  plane  not  heretofore  occupied  by  it.  In  the 
large  proportion  of  cavities  occurring  in  the  class  under  consideration, 
this  practice  stands  for  much  in  the  saving  of  these  teeth. 


CAVITY  PREPARATION  OF  THE  MAJOR  CLASS  FOR  MATRIX 

WORK 

The  subject  of  cavity  preparation  comes  up  in  connection  with  the 
matrix  as  a  matter  of  first  importance. 

The  form  of  cavity  preparation  ordinarily  employed  in  cases  of  extreme 
decay  of  proximal  surfaces  of  molars  and  bicuspids  answers  in  some 
measure  in  matrix  work. 

In  the  description  of  cavity  preparation  the  terms  depth,  width,  and 
length,  as  applied  to  the  several  walls  of  the  cavity,  should  be  limited, 


240 


USE  OF   THE  MATRIX   /.V  FILLIXG  OPERATIOXS 


and  apply  to  particular  j)<)iiits,  and  particular  j)()iiits  only.  I-'or  instance, 
the  depth  of  a  cavity  should  mean  from  the  point  of  decay  toward  the 
pulp,  whether  penetratini;;  from  the  occlusal,  mesial,  distal,  buccal,  or 
lingual  aspect  of  the  tooth.  The  width  should  mean  from  side  to  side 
of  the  cavity,  whether  on  the  occlusal  nie-sial,  distal,  buccal,  or  lingual 
surface  of  the  tooth.  The  length,  the  longest  dimension,  should  mean 
the  izreatest  lenirth,  in  whatever  direction  it  extends.  The  bottom  of 
a  cavity  should  be  called  the  floor,  as  seen  at  a  and  d,  Fig.  247.  By 
reference  to  Figs.  247  and  248  the  tooth  shown  represents  a  left  lower 
molar,  the  decay  of  which  penetrates  from  the  mesial  surface  in  the 
direction  of  the  line  leading  from  f,  and  we  would  say  that  the  depth 
of  the  cavity  seen  at  a  and  c  was  in  that  direction;  and  that  its  width 
was  !)ucco-lingual,  from  e  to  e,  or  from  c  on  the  buccal  side  to  a  point 
opposite  on  the  lingual.  This  cavity,  being  a  compound  one,  must  have 
added  together  for  its  length,  the  f^oor  of  the  step  d,  the  axial  wall  F,  and 
the  floor  A.  The  de[>th  of  the  lingual  and  buccal  walls  is  seen  at  c,  and 
the  depth  of  the  floor  at  a.  The  axial  wall  and  lieight  of  it  is  seen  at 
F,  and  the  floor  of  the  step  at  d. 


Fig.  247 


Fig.  248 


Fig.  249 


vr^'C 


Cavity  preparation  of  a  molar 
for  the  matrix. 


E 

F 
A         B 

Cavity  preparation,  showing  square 


Seftion  of  molar, 
.showing  the  introduc- 
tion of  the  cushion. 


In  Fig.  247  is  represented  the  cavity  preparation,  with  which,  in 
connection  with  the  matrix  and  soft  and  cohesive  gold,  the  operator  is 
enabled  to  bring  gold  work  in  cavities  of  this  class  to  a  degree  of  per- 
fection rarely  approximated  without  its  aid. 

At  the  cervical  margin  of  Figs.  247  and  248  it  will  be  ob.served  that 
the  floor  of  this  aspect  of  the  cavity,  a,  and  the  external  wall  of  the 
tooth,  B,  form  practically  right  angles,  which  is  the  angle,  all  things 
considered,  with  which  to  secure  the  best  margins  and  best  results. 

Beginning  well  up  on  the  side  wall  at  C,  Fig.  247,  passing  down  and 
along  the  base  of  the  cement  step  and  up  the  opposite  wall,  is  a  groove, 
C,  better  shown  in  the  sectional  cut.  Fig.  249,  made  with  a  No.  3  or  4 
round  bur,  or  Darby-Perry  excavator,  Xos.  11  and  12,  designed  as  an 
anchorage  for  the  base  of  the  cervico-occlusal  column,  marked  non- 
cohesive  gold.  Fig.  2-51.     In  this  groove,  which  should  be  shallow  and 


(•AVITY  PREPARATION  FOR  MATRIX    WORK 


241 


iij)()n  the  floor  surface.  A,  is  condensed  the  gold.  The  groove  exteiuHug 
up  the  side  wall  is  not  a  necessity,  though  it  may  be  incorporated  in  the 
cavity  formation  when  the  walls  are  strong,  hut  that  portion  of  it  along 
the  Moor  should  he  employed. 

In  the  instances  where  the  lateral  walls  are  weak  and  the  groove 
cannot  i)e  formed,  the  occlusal  anchorage  shown  at  d.  Figs.  247  and  248, 
should  he  employed.  In  the  formation  of  the  side-wall  edges,  e  e,  Fig. 
248,  care  must  be  taken  to  leave  them  strong  enough  to  prevent  fracture 
under  the  pressure  of  the  matrix  band.  These  walls  should  be  bevelled 
on  the  lines  e  e.  Fig.  248,  terminating  in  an  obtuse  angle  with  the  external 
surface  of  the  tooth,  if  practicable.  Less  than  a  right  angle  should 
not  be  depended  on,  if  it  can  be  avoided,  as  there  is  danger  of  fracture. 


Fig.  250 


A— -^ 


Fig.  251 

"COHESIVE  GOLD. 

r  ^IpS---— CEMENT. 

-NON  COHESIVE  GOLD. 


Fig.  252 


Cavity  preparation,  showing 
subdivisions  of  filling. 


Section  showing  the  plan 
of  a  matrix  filling. 


Section  showing 
the  condensation 
of  cushion  K  of 
Fig.  249. 


In  the  formation  of  the  cavity  in  Fig.  247,  with  the  rounded  corner 
c,  is  seen  the  preparation  suitable  for  amalgam  or  other  plastic  materials 
in  connection  with  the  matrix;  and  for  cushions  and  cylinders  of  foil  if 
the  cavity  approximates  the  form  seen  in  Fig.  248,  and  at  f  and  h  of 
Fig.  252.  But  these  corners  should  be  modified  as  nearly  as  possible 
into  the  form  seen  at  n  n,  Fig.  248,  if  the  cavity  is  shallower  from  a  to 
D,  Fig.  248,  than  from  f  to  h.  Fig.  252. 

The  scjuare  corners  aid  in  better  locking  and  binding  the  foundation 
subdivisions  in  the  process  of  building  in  the  filling  (see  Fig.  250). 

But  when  the  cavity  assumes  the  proportions  seen  at  f  to  h,  Fig.  252, 
the  matter  of  square  corners  is  not  necessary,  liecause  when  the  distance 
from  the  top  of  the  step,  Fig.  252,  to  the  floor  is  greater  than  from  f  on 
the  axial  wall  to  h  on  the  matrix  band,  we  have  a  form  of  cavity  in  w^hich 
the  cushions  and  cylinders  bind  and  hold  without  the  aid  of  square 
corners. 

It  vshould  be  a  rule  of  practice  to  put  in  cement  steps  wiienever  the  dis- 
tance from  the  axial  wall  to  the  matrix  band  is  greater  than  from  the  top 
of  the  step  to  the  floor  of  the  cavity,  and  bring  the  form  of  the  cavity  as 
nearly  as  possible  into  that  shown  in  Figs.  249,  252,  253,  and  255;  be- 
cause, first,  it  necessitates  the  use  of  less  metal,  w^hether  of  gold  or  tin; 
16 


242 


LSE  OF   Till':   MATRIX    IS   FlLLlSd  Ol'KUATlOX.S 


second,  it  is  better  when  (iiiislied,  and  more  (piickly  filled  to  the  (op  of 
the  step  (Fig.  253);  and  third,  it  avoids  the  formation  of  the  s(juare 
oorners,  N  N,  Fig.  248,  extending  so  deeply  toward  the  pnlj)  as  to  weaken 
the  walls  of  the  tooth. 

In  the  iiitnxhiction  of  the  filling  into  the  corners  of  Fig.  248,  the 
method  snggested  is  to  carry  in  the  cushion  of  soft  gold  or  tin,  as  the 
case  may  l)e,  and  place  in  the  corner  at  A  with  pluggers,  Nos.  257,  258, 
or  25!),  Fig.  291,  whatever  size  of  these  forms  shall  best  suit  the  case, 
and  ])ar(ially  condense  it.  In  the  opposite  corner  place  in  the  subdivi- 
sion M,  and  (hen  the  subdivision  c.  Only  this  last  introduction  is  carried 
straight  down  in  the  direction  of  the  long  axis  of  the  tooth,  while  the 
other  subdivisions,  as  seen  in  Fig.  250,  are  placed  in  diagonally  and 
compressed  in  place.  At  this  juncture  hold  down  with  a  suitably  shaped 
instrument.  No.  174  or  175,  Fig  291,  on  one  side  and  condense  the  other 
with  the  automatic  mallet  carrying  a  suitably  shaped  plugger.  No.  18, 
F^ig.  291,  until  adequately  condensed.     After  this,  change  instruments 


Fig.  254 


Fig.  255 


Section  showing  cervico-oc- 
clusal  wall  built  to  top  of  step. 
(t,  groove  for  the  gr;isp  of  the 
capping  slab. 


Section  of  pulpless  molar 
before  placing  in  the  cement 
step. 


Section  showing  the  recon- 
struction of  pulpless  molar 
with  cement  step. 


about,  and  treat  the  opposite  side  in  a  similar  manner.  If  the  cushions 
are  proportioned  properly  to  the  size  of  the  cavity,  two  sets  of  each  of  these 
put  into  subdivisions  a,  b,  and  c,  Fig.  250,  will  bring  the  wall  to  the 
top  of  the  step,  or  nearly  so. 

F'ig.  247  represents  the  preparation  of  tlecay  cavities,  whether  appear- 
ing on  bicuspids  or  molars,  the  outer  outline  of  which  a])pears  in  Fig. 
256  and  comes  under  the  head  of  the  major  class.  All  such  decays 
should  as  nearly  as  practicable  be  prepared  after  the  suggestions  of 
Fig.  247. 

In  the  formation  of  the  cavity  in  Fig.  247,  when  the  tooth  is  normal 
and  its  functions  comfortably  performed,  care  must  be  exercised  to  avoid 
too  near  approach  to  the  pulp,  particularly  when  the  cavity  is  located  in 
bicuspids,  in  which  case  we  have  a  shallower  zone  in  which  to  work  than 
is  found  in  the  corresponding  parts  of  molars.  In  the  deeper  cavities  of 
bicuspids  and  molars,  zinc  phosphate  should  be  used  to  bring  the  cavity 
into  simple  form,  as  seen  in  Figs.  251,  254,  and  255. 


CAVITY  PREP  A  RAT  ION  FOR  MATRIX   WORK  243 

WluMi  these  cavities  are  j)rej)are(l  after  the  siii>'^estioiis  and  ilhistra- 
tioiis  of  the  figures  referred  to  and  enil)raeed  by  the  matrix,  not  only  is 
less  material  needed  to  bring  up  the  cervieo-occlusal  wall  to  the  top  of  the 
stej),  hut  additional  advantages  are  gained  in  that  the  cavity  is  simpli- 
fied, the  lining  rendered  easy  of  execution,  and  the  character  of  the  work 
improved. 

().\yj)hosphate  of  copper  cement,  being  more  adhesive  and  less  a 
thermal  conductor,  and  possessing  more  of  antiseptic  property  than  the 
other  forms  of  zinc  cements,  should  be  employed  wherever  practicable 
for  step  making.  Its  inky  blackness  perhaps  is  against  its  use  in  the 
anterior  teeth,  and  farther  forward  than  the  molars.  But  it  is  also  less 
irritant  and  is  harder  and  stronger  than  any  of  the  zinc  phosphates. 
So  that,  in  the  instances  where  the  cavity  penetrates  to  or  beyond  the 
pulp,  and  compels  the  formation  of  a  cavity  as  deep  from  the  matrix 
band  to  the  axial  wall,  as  is  shown  in  the  pulpless  tooth,  Fig.  254,  or  as 
already  cited,  when  the  depth  of  the  cavity  from  f  to  h.  Fig.  252,  is 
greater  than  the  height  of  the  step,  the  cement  should  be  placed  in  posi- 
tion to  bring  the  axial  wall  close  enough  to  the  matrix  band  to  form  the 
cavity  into  the  proportions  shown  in  Figs.  249,  252,  and  253  when  em- 
braced by  the  matrix. 

This  class  of  cavities,  when  filled  with  gold,  should  be  filled  with  soft 
gold  cushions  or  cylinders  to  the  top  of  the  step  d.  Figs.  247  and  248, 
when,  after  forming  the  groove  shown  at  G,  Figs.  251  and  253,  should 
be  completed  with  cohesive  gold  and  built  securely  in  place.  The 
anchorage.  Figs.  247,  248,  and  250,  at  d,  indicate  what  this  should  be. 

The  procedure  in  the  introduction  of  the  soft-gold  part,  or  of  tin  when 
that  is  used,  in  the  major  class,  is  seen  at  k.  Fig.  249,  and  when  con- 
densed, at  L,  Fig.  252.  The  introduction  is  in  the  direction  of  the  long 
axis  of  the  tooth  and  not  diagonal,  as  shown  in  Fig.  250,  although  the 
diagonal  introduction  may  be  employed  in  special  cases  favoring  it. 
The  cushions  thus  introduced,  rarely  less  in  size  and  bulk  than  a  size  3 
cylinder,  and  generally  much  larger,  do  not  fill  up  squarely  out  to  their 
ends  or  to  the  lateral  walls;  and  the  operator  must  look  to  these  points, 
and  level  them  up  with  small  cylinders  or  their  equivalent  in  cushions. 

The  final  condensing  of  this  column  as  seen  at  i.  Fig.  253,  and  before 
the  cohesive  part  is  begun,  should  be  done  by  holding  down  the  gold 
at  one  side  of  the  cavity,  while  the  automatic  mallet  condenses  at  the 
opposite,  as  suggested  in  the  filling  of  the  cavity  of  Fig.  248.  The 
student  must  appreciate  the  importance  of  condensing  first  the  soft  gold 
at  N,  and  afterward  the  cohesive  at  e.  Fig.  248,  when  that  figure  is  em- 
braced by  the  matrix.  Pluggers  Nos.  7  or  8,  Fig.  291,  of  small  treading 
surface,  are  suitable  for  doing  this  part  of  the  work.  The  cohesive  gold 
should  be  used  in  narrow  strips  when  the  angle  into  which  it  must  go  is 
close  and  sharp. 

It  is  the  purpose  in  engineering  construction  to  secure  the  greatest 


244 


USE  OF  THE  MATRIX  IN  FILLING  OPERATIONS 


possible  strength  from  tlie  arrangement  of  material  entering  into  sueh 
construetion.  In  the  formation,  therefore,  of  the  anchorage  for  the  fill- 
ings of  the  major  class  of  the  cervico-occhisal  cavities,  (hie  regard  mnst 
he  given  to  the  proportion  of  gold  and  enamel  in  making  the  anchorage 
head  in  the  occhisal  surface  of  fillings  of  this  class. 

Just  as  it  is  ])ossil)le  to  weaken  a  carriage  wheel  l)y  having  the  tenons 
of  the  spokes  so  large  as  to  weaken  tlie  huh,  it  is  also  possihie  to  have 
tiie  tenons  so  small  and  tlie  hu!)  so  strong  as  from  this  cause  to  weaken 
the  wheel.  So  also  with  the  anchorage  of  this  class  of  fillings;  the  neck 
of  irold  u'oini;  into  the  head  of  the  anchorage  maybe  so  small,  narrow, 
and  shallow  that  the  stress  of  chewing  will  cause  it  to  break  at  this  point. 
And  yet  the  neck  may  be  widened  and  deepened  so  much  that  the  gold 
becomes  stronger  than  is  necessary,  and  the  enamel  on  either  side  l)ecomes 
correspondingly  weak,  and  gives  way  luider  stress  of  mastication. 

The  problem  then  is  to  proportion  the  neck  of  gold  and  the  enamel  so 
as  to  secure  the  greatest  strength. 

Assuming  the  depth  of  the  gold  neck  to  be  about  its  width,  the  rule 
of  one-third  gold  in  width  and  two-thirds  enamel,  one  third  each  side 
of  the  gold,  answers  the  requirement. 


THE  MINOR  CLASS 

While  the  principles  inculcated  by  l)rs.  Webb,  Black  and  others  in 
extension  for  prevention — extending  the  cavity  margins  well  away  from 
the  contact  point  of  the  teeth — hold  good  in  the  larger  {)roportion  of  cases, 
there  are  those  individual  instances  presenting  when  the  operator  will  not 


Fig.  256 


Fig.  257 


Fig.  258 


Bicuspid,  showing  the 
major  and  minor  class 
cavity  outline. 


Side  view,  showing  the  outline  of  the 
major  and  minor  preparation. 


Transaxial  section,  show- 
inc  anchorage  of  the  minor 
class  at  line  .1  of  Fig.  257. 


be  justified  in  employing  extension  for  prevention.  Take,  for  instance, 
the  highly  developed  teeth,  with  perfectly  fused  enamel  through  the 
sulci  dividing  the  cones,  lobes,  and  cusps  of  the  molars  and  bicuspids, 
which  from  the  excellence  of  their  quality  and  the  cleanliness  of  the 
patient  almost  entirely  prevent  caries;  it  would  be  unwise  and  unneces- 
sary under  these  conditions  to  extend  in  preparation  the  borders  of  these 
cavities  to  the  extent  taught  and  endorsed  in  extension  for  prevention,  and 
yet  so  necessary  in  many  of  the  larger  decays  denominated  the  major 
class. 


THE  MINOR  CLASS 


245 


The  prepanitioii  of  (he  minor  chiss  of  decays,  represented  in  the  inner 
oiitHiie  of  Fit;-.  2'iC),  should  he  formed  after  the  suggestions  (jf  Figs.  257, 
258,  and  25! >.  The  student  should  comprehend  the  formation  of  both 
the  major  and  minor  (lass,  as  each  must  he  prepared  according  to  the 
suggestions  made. 

The  preparation,  therefore,  for  the  minor  class  may  be  enlarged  to  the 
proportions  shown  in  the  inner  outline  of  Fig.  257,  while  the  outer  out- 
line of  Figs.  257  and  250  would  show  the  formation  of  the  major  class 
on  the  same  tooth. 

Fig.  2()()  is  a  sectional  cut  showing  the  completed  major  class  of  the 
cer\  ico-occlusal  fillings,  as  adapted  to  and  completed  in  the  bicuspitl. 

Fio'.  25<S  is  a  transaxial  section  at  the  line  a  on  Fig;.  257;  and  at  this 
point  the  anchorage  for  the  minor  class  is  seen  in  Fig.  258.  The  anchor- 
age can  and  should  be  made  strong  here  under  the  buccal  lobes  of  bicus- 
pids and  molars,  and  similarly  at  the  lingual  sides.  Above  the  anchor- 
age, toward  the  occlusal  surface,  the  cavity  should  be  so  modified  as  to 
con.ie  out  on  the  occlusal  surface,  as  showni  in  Fig.  259. 


Fig.  259 


Fig.  260 


Fig.  261 


End  \new,  showing  out- 
line of  major  and  minor 
cavity  preparation. 


Section  showing  the  com- 
pleted major  class  filling  on 
bicuspid. 


M,  2-grain  cube  of  gold, 
showing  relative  size  to  the 
cavity  in  which  it  rests. 


The  pluggers,  Nos.  115  and  116  or  117  and  118,  Fig.  291 — pairs  in 
two  sizes — are  invaluable  for  tacking  the  cohesive  gold  into  the  condensed 
soft  gold.  INIuch  of  this  part  of  the  work  must  be  done  by  hand  pressure; 
and  it  is  important,  in  view  of  this  fact,  to  prepare  the  gold  in  narrow 
strips,  which  should  be  annealed  wdth  electric  heat  to  insure  the  strongest 
cohesion. 

In  the  filling  of  this  class  of  cavities  the  matrix  should  be  applied, 
and  soft  gold  brought  up  to  the  anchorage  show^n  in  Fig.  258.  At  this 
point  cohesive  gold  should  be  thoroughly  condensed  into  the  anchorages, 
and  brought  out,  finishing  the  contour  of  the  tooth.  Care  should  be 
taken  to  bevel  somewhat  the  occlusal  surface  of  this  filling  to  prevent  the 
too  positive  impinging  of  the  occluding  tooth  in  the  opposite  jaw. 

The  beginning  of  the  cohesive  on  the  condensed  soft  gold  and  the 
fastening  .of  it  there,  in  w^hatever  class  of  cavities,  depends  on  careful 
attention  to  several  details:  First,  the  operator  must  so  conduct  his 
operation  as  to  control  the  saliva  perfectly,  keeping  his  work  dry.    Second, 


240  VSE  OF   THE  MATRIX   IN  FILL  INC  OPERATIONS; 

tilt'  matrix  imist  1)0  fixed  and  rioid  in  its  aj)j)lieati()ii.  'riiird,  the  j)lu(fj^pr.s 
should  be  kcj)t  freshly  serrated,  and  of  such  forms  as  (five  direct  eiitrauee 
to  and  aj)|)lication  of  them  at  the  j)oint  on  the  work.  Fourth,  the  serra- 
tions should  l)e  clean  and  deej).  Fifth,  the  <j;old  should  l>e  clean,  and 
freshly  annealed.  Any  of  the  forms  of  cohesive  <;'oId  may  l)e  used  if 
the  portions  carried  each  time  to  their  destination  are  small,  clean,  and 
annealed.  Small  cohesive  "old  cylinders,  \os.  {  and  \,  are  easily  used 
for  this  work,  and  the  smaller  ones  shoidd  not  only  he  employed  to 
begin  with,  when  this  form  is  used,  but  as  far  as  practicable  thnnighout. 
The  strips  or  ril)l)()ns,  however,  of  cohesive  gold  when  freshly  annealed, 
and  with  all  other  conditions  above  enumerated  complied  with,  give  best 
re.suits.  The  ribbon  is  tacked  or  pricked  into  the  soft  gold  ])y  interdigita- 
tion,  and  the  union  made  with  this  or  any  preparation  of  cohesive  gold 
wliile  not  strong,  is  enough  so  to  enable  the  operator  to  reach  his  anchor- 
age points,  where  he  may  thoroughly  secure  the  work. 

In  making  matrix  fillings,  if  the  matrix  employed  is  of  the  band  or 
loop  variety  and  has  no  separating  feature,  in  order  to  secure  contour, 
and  to  have  the  fillings  finished  in  the  original  form  of  the  tooth,  the 
teeth,  if  two  are  together,  should  have  the  cavities  previously  packed  with 
cotton,  long  enough  to  produce  mobility  of  them,  so  that  they  may  more 
easily  yield  apart.  This  then  gives  opportunity  to  push  the  teeth  apart 
still  farther,  especially  with  those  matrices  provided  with  the  separating 
feature,  and  so  to  gain  room  in  which  to  shape  the  matrix  band  and  to 
reproduce  the  contour  of  the  tooth. 


PREPARATION  OF  GOLD  FOR  MATRIX  WORK 

In  the  soft-gold  part  of  matrix  work  the  form  of  the  gold  to  be  em- 
ployed is  important  to  be  imderstood.  Large  cylinders  and  cushions  in 
comparison  with  those  ordinarily  used  in  cavities  of  given  size  are  not 
only  more  safely  and  perfectly  adapted,  but  more  (juickly  done,  'i'his 
results  from  doubling  and  partly  compressing  the  cushions,  which,  being 
further  susceptible  of  compression,  are  still  large  enough  to  stpieeze  m 
place  and  l)ind  as  they  are  compressed. 

In  placing  cushions  into  the  bottom  of  large  cervico-occliisal  cavities 
of  molars  and  bicuspifls  embraced  by  the  matrix,  it  is  important  to  start 
with  those  of  sufficient  size  and  density  to  bind  as  they  are  condensed, 
but  it  is  not  to  be  understood  that  the  first  such  piece  introduced  must  be 
fully  condensed  before  other  similar  pieces  are  added.  If  this  practice 
were  followed,  notwithstanding  the  fact  that  the  first  piece  introduced 
binds  as  it  is  condensed,  this  is  so  only  to  a  certain  point  of  the  conden- 
sation. Beyond  this,  if  we  continue  it.  especially  to  that  denuity  which 
may  be  obtained  against  the  resistance  the  tooth  afi'ords,  it  loosens,  will 
tilt  and  rock,  and  is  worthless.     But  if  after  placing  in  one  cushion, 


PREPARATION  OF  COLD  FOR  MATRIX   WORK  247 

which  the  operator  learns  to  proportion  to  the  size  of  the  cavity,  and 
partially  condensing  it,  he  introduces  another  and  carries  the  conden- 
sation to  the  point  of  the  first,  and  still  another,  he  may  then  mallet  until 
the  mass  will  yield  no  more;  and  the  wall  of  soft  gold  thus  built  will  be 
steady,  well  adapted,  moisture  proof,  and  impervious  to  leaking  by 
capillary  force.  This  comes  of  the  fact  that  when  three  or  more  cushions 
or  cylinders  are  carried  down  as  described,  the  bearing  up  and  down  the 
axial  and  matrix  walls  is  sufficient  to  msure  binding  and  steadiness. 

In  the  illustration.  Fig.  249,  will  be  observed  at  k  a  gold  cushion 
entering  the  cavity  between  the  axial  wall  F  and  the  matrix  band  H. 
The  cushion  is  made  of  one-half  of  the  gold  twist  shown  at  Fig.  262, 
and  contains  two  grains  of  gold  by  weight.  This  cushion,  when  con- 
densed to  its  ultimate  density,  as  by  melting  and  hammering,  is  repre- 
sented in  cube  form  and  exact  size  at  M,  Fier.  261. 

Fig.  262 


Leaf  of  No.  4  gold  foil,  twisted  ready  for  formation  into  cushions. 

A  No.  4  gold  cylinder,  as  made  by  the  manufacturer,  one-fourth  of  an 
inch  long,  contains  one  grain  of  gold  by  weight,  and  when  this  is  con- 
densed into  cubic  form  it  is  one-half  the  bulk  of  the  cube  shown  at  m. 
Fig.  261.  It  transpires  then  that  the  large  loosely  made  No.  4  cylinders  of 
one  grain  weight  are  more  difficult  of  satisfactory  adaptation  than  those 
which  contain  the  two  or  more  grains,  because  the  large  loose  ones  lack 
the  bulk  and  substance  which  is  necessary  to  cause  them  to  bind  and 
fasten  in  condensing. 

It  will  be  seen  further,  by  comparison  of  the  2-grain  cube  m.  Fig. 
261,  with  the  proportions  of  the  cavity  in  which  it  rests,  that  it  reaches 
hardly  half  across  the  cavity,  bucco-lingually,  and  that  if  this  cube  WTre 
elongated  so  as  to  reach  across  the  cavity,  its  bearing  against  the  axial 
wall  and  the  matrix  band  would  be  lowered  at  least  one-half,  and  there 
would  not  be  sufficient  bearing  up  and  down  these  walls  to  hold  the  gold 
fixedly  in  place.  This  then  demonstrates  the  difficulty  of  adapting  gold 
or  tin  foil  at  such  points  with  cylinders  or  cushions  containing  less  than 
enough  material  to  bind  and  hold  the  mass  in  place  in  the  process  of  con- 
densing. And  if  this  be  true,  as  is  illustrated  in  Fig.  261,  it  is  seen  that 
the  size  4  cylinder,  containing  only  one  grain,  would  be  still  inore  difficult 
to  control,  because  it  lacks  in  greater  degree  the  bulk  and  substance 
sufficient  to  give  the  bearing  up  and  down  the  walls  necessary  to  the 
binding  and  fastening  in  the  process  of  condensing.  Neither  will  the 
cylinders  or  cushions  containing  two  grains  or  more  in  very  large  cavi- 
ties bear  complete  condensing,  before  adding  other  pieces  without  loosen- 
ing, for  the  reasons  already  given.  In  exceptionally  large  cavities  of  the 
major  class,  a  sheet  of  No.  4  foil  may  be  formed  into  a  single  cushion, 


248  USE  OF   Tl/K   MATRIX   IN   FILLISd  OI'FRATIOXS 

and  introduced  to  iidvantage.  Such  a  cushion  contuiniiii;-  four  frj-ains 
would  not  build  higher  than  is  necessary  to  hind,  even  if  it  were  formed 
into  a  rectani^ular  })arallel()j)ij)ed — two  cuhes  side  by  side,  and  cxtcncHng 
from  one  lateral  wall  to  the  other. 

The  successful  making  of  fillings  with  either  gold  or  tin  is  not  so 
much  a  cjuestion  of  securing  the  ultimate  density  of  these  materials,  as 
that  of  securing  adaptation  of  them  to  the  walls  of  the  cavity  in  such 
manner  as  shall  prevent  leakage  beneath,  in,  and  around  the  filling.  This 
result  may  be  obtained  with  a  compression  or  condensation  of  much 
less  density  than  is  shown  in  the  melting  of  them,  or  as  is  obtainable 
against  the  resistance  which  the  tooth  ott'ers. 


FORMATION  OF  CUSHIONS  FROM  FOIL 

The  cushion  of  either  gold  or  tin,  rather  than  the  cylinder,  is  a  better 
preparation  for  matrix  work,  even  when  it  is  made  from  cylinders  com- 
pressed or  doubled  upon  themselves,  because  the  cushion,  made  of  foil, 
while  soft  enough  to  be  adapted  to  the  irregularities  of  the  cavity,  contains 
from  twice  to  four  times  the  amount  of  material  which  the  loose  cylinders 
do,  and  because  of  this  fact,  in  connection  with  proper  handling  and 
cavity  formation,  they  are  more  easily  secured  in  place. 

The  student  should  appreciate  the  fact  that  until  he  succeeds  in  laying 
the  foundation  of  soft-gold  work  in  a  manner  to  prevent  its  moving  or 
shifting  position  in  the  process  of  condensing,  he  will  have  failed  to 
secure  the  results  within  his  reach.  The  employment  of  the  cushion, 
therefore,  rather  than  the  cylinder,  is  urged  as  die  best  means  to  this 
end. 

The  formation  of  cushions  from  the  foil  is -as  follows:  Take  a  full 
leaf  of  No.  4  soft  gold  foil,  and  with  clean  hands  crimple  and  wrinkle 
it.  Straighten  this  out,  but  leave  the  sheet  undulated,  when  it  should 
be  loosely  folded  three  to  four  times  upon  itself  and  loosely  twisted.  The 
twist  thus  made  shoidd  l)e  cut  into  from  three  to  five  pieces,  Fig.  202, 
depending  on  the  size  of  the  cavity  to  be  filled.  The  large  cavities, 
such  as  are  seen  in  the  proximal  surfaces  of  molars,  Figs.  247  and 
248,  will  take  a  cushion  made  from  the  longer  section  of  the  twist  shown 
in  Fig.  202,  which  may  represent  one-half  or  more  of  the  sheet  of  No.  4 
foil;  while  cavities  of  the  proportions  shown  in  Fig.  257  will  take  one- 
fourth  or  less.  Smaller  proximal  cavities  in  the  incisors  will  take  from 
one-fifth  to  one-third  of  a  half-sheet  prepared  after  the  manner  of  Fig. 
262.  The  cushions  prepared  after  these  suggestions,  when  used  for  the 
large  cavities  of  the  molars  and  bicuspids,  should  somewhat  resemble  the 
illustration  in  Fig.  2()3.  The  preparation  thus  made  is  more  desirable 
than  the  cylinders  made  of  soft  foil,  because  it  is  more  easily  manip- 
ulated and  with  better  results,  and  because  die  student  learning  to  do 


FINISfllNO  rilE  FILLING  249 

this  secures  to  himself  a  resource  wliicli  enables  him  to  prepare  his 
cushit)n.s  for  all  sizes  of  cavities,  and  is  never  at  a  loss  for  what  is  wanted 
when  foil  is  to  he  had. 

But  when  this  class  of  work  is  to  be  done  with  tin  foil,  the  cylinders^ 
compressed  or  doubled,  will  serve  best,  since  it  is  difficult  to  obtain  a  foil 
of  tin  light  enough  and  soft  enough  to  make  desirable  cushions. 

Fig.  263 


Cushion  formed  from  twisted  leaf  of  Fig.  262,  or  from  partially  compressed  cylinders. 

Tin  foil  in  cusliions,  made  by  doubling  the  cylinders  upon  themselves 
for  the  foundation  portion  of  cervico-occlusal  fillings,  in  connection  with 
the  matrix,  and  under  the  finishing  slab  of  cohesive  gold,  works  even 
more  kindly,  and  adapts  more  easily  than  cushions  made  from  soft 
gold  foil;  and  if  its  use  here  is  not  forbidden  by  electrolysis,  it  is  to  be 
given  first  place  as  a  tooth  preserver  at  the  cervical  margins,  and  as  a 
non-conductor  of  the  thermal  changes  to  the  pulp.  Tin  foil  and  soft 
gold  foil  laid  together,  and  the  two  formed  into  cushions  after  the  sug- 
gestions already  made,  may  be  used  with  results  quite  as  beneficial  for 
preservation  of  the  margins  embraced  by  the  matrix  as  when  gold  or  tin 
alone  is  used,  with  the  advantage  of  avoiding  the  danger  of  electrolysis  of 
tin  under  gold. 

FINISHING  THE  FILLING 

No  part  of  the  work  of  making  gold  fillings,  such  as  are  included  in 
the  major  class  particularly,  is  more  laborious  than  the  finishing  of  them. 
Yet  when  the  matrix  has  been  properly  adapted  to  the  teeth,  the  finishing 
of  the  cohesive  gold  part  may  be  lessened  to  the  minimum. 

The  more  rapid  and  satisfactory  finishing  of  the  work  following  the 
use  of  the  matrix  is  no  small  part  of  the  advantage  of  this  device,  since 
the  matrix  gives  not  only  the  form  of  the  wall  which  it  embraces,  but 
more  than  any  other  method  yet  devised  saves  filling  material.  This 
comes  of  the  fact  than  when  it  is  properly  adjusted  the  cavity  is  converted 
into  a  mould  so  nearly  the  shape  of  the  filling  to  be,  that  when  it  has 
been  made  very  little  work  remains  to  be  done  in  polishing. 

The  first  step  toward  polishing  after  removing  the  matrix  is  to  go 
around  the  borders  of  the  soft-gold  portion  of  the  filling  with  a  blade 
burnisher,  which  should  be  kept  highly  polished  and  clean.  In  this 
operation  the  object  should  be  to  compress  as  much  as  possible  by  hand 
pressure  the  soft-gold  portion  that  may  have  bulged  under  the  malleting. 
After  this  the  Rhein  trimmers,  Nos.  31  and  32,  should  go  over  the 


250  I'SE  OF   THE   MATRIX   I .\   FILLINC  Ol'KHATlOSS 

borders,  and  should  Iclicld  so  tliiit  (he  blade  shall  rest  erjiially  on  (he 
lilliiii;-  and  the  adjacent  exli'i'nal  snrfaee  of  the  tooth. 

At  this  j)()int,  it'  the  operation  is  between  molars  or  biensjjids,  the 
Perrv  separator  is  valuable,  and  should  be  placed  so  as  to  have  the  beaks 
inipinoe  above  the  margin  ol  the  fillin<>;,  and  should  be  made  to  open 
the  teeth  onh'  enou(>h  to  {)ass  in  the  thinnest  strips  and  sandpaj)er  disks. 
Care  and  skill  are  recpiired  in  the  hantUinif  of  disks  to  a\()id  grinding; 
away  the  contour  of  the  filling,  but  the  disk  can  be  so  held  as  to  prevent 
this. 

The  author  Hnds,  in  removing  the  overhanging  corners  of  the  cohe- 
sive portion  of  these  fillings,  that  the  use  of  a  stiff  five-eighths  inch  garnet 
disk,  held  only  to  the  corners  and  not  permitted  to  pass  in  between  the 
teeth,  answers  better  than  any  form  of  corundum  or  carborundum 
wheels. 

After  thus  carefully  shaping  the  cap  or  slab  of  cohesive  gold  at  the 
contact  points,  and  rounding  them  as  the  case  permits  and  re(|uires.  Hint 
strips  and  the  "regular"  grit,  followed  with  the  "fine"  cuttlefish  disk, 
completes  the  polish. 

The  occlusal  surface  of  cohesive  gold  is  easily  shaped  with  corundum 
wheels  and  polished  with  the  cuttlefish  disk,  when  these  can  Ije  made  to 
apply,  or  Avith  leather  wheels  carrying  pumice. 

There  is  no  essential  difference  in  polishing  the  major  and  minor  class 
of  these  fillings,  except  in  the  extent  of  the  w^ork. 


FORMS  OF  MATRICES  FOR  MOLARS  AND  BlCUSPmS 

A  presentation  of  all  the  devices  known  as  matrices  is  not  the  purpose 
of  this  chapter,  but  only  of  those  whose  efficiency  commends  them. 

Fig.  2f)4  represents  the  set  of  matrices  devised  by  Dr.  Louis  Jack. 
This  set  of  matrices  is  provided  W'ith  concave  surfaces  for  contouring  the 
teeth,  which  indicates  the  high  ideal  of  the  originator  of  the  device. 
They  are  made  thick  and  heavy  at  the  base  of  the  lateral  edges,  which 
aids  in  steadying  them  between  the  teeth,  and  they  are  provided  with 
slotted  edges,  which  engage  a  special  pliers  to  insert  and  remove. 

Fig.  205  show^s  a  set  of  loop  matrices,  which  at  times,  and  with  teeth 
of  slight  constriction  at  the  neck,  answer  w'ell;  but.  like  all  of  the  loop 
variety,  they  require  space  at  both  sides  of  the  tooth  to  admit  of  adjust- 
ment. 

Fig.  266  exhibits  a  set  of  matrices  devised  by  Dr.  Truman  W.  Brophy, 
which,  with  the  flexibility  of  the  thin  steel  bands  and  under  the  action 
of  the  screw%  may  be  made  to  aid  the  operator  most  acceptably. 

The  l)and  is  not  unlike  the  loop  in  the  matter  of  passing  between  the 
teeth,  and  the  teeth  must  yield  apart  to  admit  it.  Still,  with  the  thinness 
of  the  bands  in  this  set,  there  is  no  difficulty  in  this  particular. 


FORMS  OF  MATRICES  FOR  MOLARS  AND  BICUSPIDS      251 

'l^liis  form  of  matrix,  however,  is  unsteady  and  (lidicult  to  fix  ri<i;idly 
on  very  sliort  crowns,  and  j)articularly  on  tliose  of  decided  conicaiity. 

Fi<>\  2G7  exhibits  an  imijroved  loop  matrix  dexised  hv  Dr.  S.  II. 
(luilford,  in  which  the  Hp  feature  is  added  for  the  purj)ose  of  havini;-  the 
band  to  catch  below  the  cavity,  without  the  necessity  of  forcing  the  l)and 


Vn:.  204 


The  matrices  of  Dr.  Louis  .lafk. 
Fig.  265 


H 


g  tig!  ip 


Loop  matrices. 
Fig.  266 


Brophy's  band  matrices. 


elsewhere  around  the  tooth  into  the  gum.  This  device,  made  in  several 
lengths  of  bands,  although  tedious  to  adjust,  from  the  fact  that  three 
pieces  must  be  handled,  is  otherwise  valuable  and  serviceable. 

Fig.  268  illustrates  Dr.  W.  A.  Woodward's  screw  matrices.  This 
form  of  matrix  has  valuable  features  in  that  the  thin  metallic  ribbon 
constituting  the  matrix  wall  may  be  made  as  thin  as  No.  36  to  38  gauge, 
and  yet  possesses  adequate  tensile  strength.  The  device  is  also  valuable 
because  in  its  use  only  one  thickness  of  the  ribbon  need  be  carried 


252 


IJHE  OF   THE   MATRIX    IS   hlLLISC  OI'E  HAT  IONS 


between  the  teedi.  Attain,  it  lias  the  sepjirutiii^  feature,  which  makes  it 
additionally  desiral)le,  as  (his  forces  apart  the  teeth  to  start  with,  and  the 
separation  is  continued  as  the  operation  proceeds,  or  as  the  exigency  of 
the  case  demands. 

Fig.  2(39  shows  illustrations  of  Dr.  K.  B.  Lodge's  matrix  hands,  ten- 
sion screws,  and  wrench.  Those  marked  a  are  adapted  to  bicuspids  and 
molars  of  usual  form,  while  those  marked  h  are  adapted  to  the  same  class 
of  teeth,  but  of  constricted  necks  and  more  pronounced  bell-shaped 
crowns,  v  and  d  of  this  illustiation  show  two  forms  of  tension  screws, 
and  F  and  e  the  wrench  for  operating  the  screw  D,  Fig.  270  shows  the 
Lodge  device  adjusted  to  the  teeth. 


Fk;.  207 


Guilford's  hand  mat  rices  and  clamps. 


Yic.  208 


Woodward's  screw  matrices. 

Tlie  bands  of  the  Lodge  matrix  are  made  of  German  silver,  and  are 
provided  with  two  eyelets  in  each,  giving  ample  range  of  adjustment. 

Figs.  271  and  272  show  a  form  of  matrix  suggested  by  Dr.  A.  C. 
Hewett,  which  for  simplicity  and  efficiency  meets  a  constantlv  occurring 
want.  In  the  instances  where  the  matrix  is  employed  between  the  teeth 
and  it  is  braced  by  an  adjacent  tooth,  and  where  no  straining  apart  of  the 
teeth  is  required,  this  device  is  admissible.  But  it  should  be  braced  with 
a  wedge,  ordinarily  at  the  cervical  edge. 


I'VIiM.'i  OF  MATlilVEH  FUR  MOLARS  AXD  BlCUSl'lDS       253 

Fi^.  273  is  a  form  of  matrix  vvliich  has  been  used  hy  the  author  in 
extenyivc  cavities  occurring  on  the  l)uccal  surfaces  of  lower  molars. 

Fig.  269 


Lodge's  system  of  loop  matrices. 
Fig.  270 


The  Lodge  matrix  in  position  on  the  teeth. 
Fig.  271  Fig.  272 


Fig.  273 


The  Hewett  matrix  held  in  position  The  Hewett  matrix  held  in  The  band  matrix 

with  the  Parmly  Brown  clamp.  position     with    the   ordinary       used    in      extensive 

rubber-dam  clamp.  buccal  surface  cavi- 

ties on  lower  molars. 

The  band  which  must  be  fitted  to  each  case  is  made  from  No.  35  to 
36  gauge  German  silver,  and  so  cut  that  the  projecting  arms  turned  down 


254  USE  OF   THE  MATRIX    IS   FJLlJAd  Of F.liAT l< )S S 

on  the  occlusal  surface  of  the  tooth  prevent  it  from  carrying-  dowii  with 
the  wedge  as  the  device  is  tightened.  In  the  instances  where  the  cavity 
extends  l)eneath  tlie  gum  the  hand  can  he  j)rovided  with  a  hj)  to  catch 
helow  tlie  buccal  margin.  The  dam  can  rarely  he  employed  in  these 
operations,  but  fortunately  it  is  not  necessary  for  the  first  part  of  this 
operation. 

When  the  lingual  and  buccal  sides  of  these  teeth  are  provided  with  al)- 
sorbent-cotton  rolls,  and  especially  when  the  saliva  ejector  is  employed, 
the  cavity  may  easily  be  filled  to  the  top  of  the  band  with  soft  gold 
or  tin,  as  suggested  elsewhere  in  this  chapter,  before  moisture  shall 
interfere. 

If  the  capping  for  this  filling  shall  be  of  amalgam,  it  may  be  finished 
within  the  time  that  the  absorbents  protect.  If  the  purpose  is  to  finish 
with  gold,  the  dam  should  at  this  juncture  be  placed  over  the  band  and 
tooth  after  the  soft-gold  part  is  brought  to  the  top  of  the  band,  and  the 
remainder  of  the  work  finished  with  coliesive  gold. 

Fig.  274  Fig.  275 


The  Hodson  contour  slip  matrices.  The  Hodson  matrix  in  position  between 

the  teeth. 

Fig.  274  represents  the  contour  slip  matrices  devised  by  Dr.  J.  F.  P. 
Hodson.  The  device  is  a  most  meritorious  one,  with  which  the  contour 
of  molars  and  bicuspids  can  be  fully  restored,  but  can  only  be  used 
between  the  teeth.  Fig.  274  gives  two  views  of  the  matrix  ready  to  be 
slipped  in  place. 

These  matrices  are  made  preferably  of  thin  annealed  steel  plate,  forged 
or  swaged  on  a  leaden  slab  with  an  oval-end  jjunch,  giving  them  what- 
ever of  concavity  the  case  may  require;  they  are  then  slipped  in  place, 
which  causes  the  teeth  to  yield  apart.  The  gingival  end  of  the  device 
should  be  braced  against  the  adjacent  tooth  with  an  orange-wood  wedge 
until  after  the  filling  is  inserted. 

The  Hodson  device  is  better  adapted  to  amalgam  work  than  gold,  be- 
cause it  does  not  possess  the  rigid  fixedness  in  sufficient  degree  to  remain 
securely  in  place  for  extensive  gold  operations. 

If  the  filling  material  used  is  a  plastic  the  device  is  left  in  place  over 
night  or  longer,  allowing  the  filling  to  set  under  pressure,  which  may  be 
done  readily,  as  the  device  shown  in  Fig.  275  is  in  no  wise  uncoiufortable 
or  troublesome  to  the  wearer. 

When  the  adjustment  of  the  matrix  is  properly  made,  it  is  unneces- 
sary in  most  instances,  particularly  in  the  upper  jaw,  to  use  the  dam. 


FOUMS  OF  MATRICES  FUR  MOLARS  AND  BlCLJSl'lDS      255 

Fi<i^.  27()  ivpresiMits  the  contour  matrix  as  devised  by  tlie  author  of 
this  chapter.  Tliis  device,  which  is  of  duplex  form,  is  only  used  Ijctween 
the  teeth,  antl  acts  in  the  three-fold  capacity  of  matrix,  separator,  and 
rubber-dam  clamp.  The  device  is  shown  in  position  between  two 
molars,  the  cavities  of  wliich  have  been  prepared  after  the  suggestions 
of  Figs.  247,  248,  and  240,  and  the  manner  of  introducing  the  cushion. 
With  this  form  of  matrix  the  teeth  may  be  drawn  apart  as  with  the  sep- 
arator, and  the  fillings  given  the  contour  the  teeth  originally  j)ossessed. 


Fig.  276 


Fig.  277 


The  Crenshaw  contour  matriv  in  position 
between  molars. 


The  contour  matrix  with  one  band  turned 
out  for  removal. 


Fig.  277  shows  the  method  of  removing  the  matrix,  as  may  be  done 
when  amalgam  is  used  without  lifting  or  unseatino-  the  fillinff.  To  do 
this  the  pin  is  withdrawn  and  the  band  embracing  the  unfilled  tooth  is 
turned  out  on  the  tension  screw  as  a  pivot.  After  this  the  band  em- 
bracing the  filled  tooth  is  lifted  away  from  it,  when  the  matrix  may  be 
removed  from  between  the  teeth.  In  amalgam  work  with  this  device 
only  one  tooth  should  be  filled  at  a  sitting,  and  after  this  filling  has  crys- 
tallized and  become  fixed  in  the  tooth  the  second  one  should  be  made. 


Fig.  278 


Fig.  279 


The  contour  matrix  holding  absorbent 
cotton  in  position. 


The  contour  matrix  in  position  between 
bicuspids. 


Fig.  278  shows  how  the  operator  may  protect  his  work  without  the 
dam  in  the  lower  jaw  by  placing  absorbent-cotton  rolls  on  each  side  of 
the  teeth,  and  how  these  are  held  in  place  by  the  matrix.  The  employ- 
ment of  the  cotton  rolls  gives  time  in  which  to  insert  amalgam  and  other 
plastic  fillings  before  the  rolls  become  saturated  with  saliva.    In  the  same 


256 


USE  OF  THE  MATRIX  IN  FILLING  OPERATIONS 


iiiiinner  the  corvico-occlusal  columns  of  these  fillings  inay  he  made  of 
^old  or  tin  cushions  to  the  top  of  the  step  with  the  aid  of  the  rolls  and 
the  saliva  ejector,  when  the  matrix  should  be  removed,  the  dam  put  over 
the  teeth,  the  matrix  reap{)lied,  and  the  operation  finished  with  cohesive 
gold. 


Fig.  280 


Fig.  281 


The  contour  matrix  in  po.sition  be- 
tween canine  and  first  bicuspid,  with 
bow  brace  attached. 


C  B 

Enlarged  figure  of  the  anterior  teeth  inatri.x:  A  and  ZJ, 
arms;  (',  projection  screw;  D,  metallic  ribbon. 


Fig.  270  .shows  the  application  of  the  short-bar  matrix  as  adapted  to 
bicuspids  and  between  canines  and  first  bicuspids.  The  bicu-spid  device 
is  better  adapted  for  use  between  molar  and  bicuspid  than  the  molar  one, 
although  the  latter  may  be  employed  at  these  points. 

Fig.  280  shows  the  contour  matrix  in  position  between  a  canine  and 
first  bicuspid,  in  connection  with  the  bow  brace,  which  prevents  the 
matrix  slipping  from  between  the  teeth,  as  it  is  inclined  to  do  on  account 
of  the  bevel  of  the  lingual  side  of  the  canine. 


MATRIX  FOR  THE  ANTERIOR  TEETH 


In  the  effort  to  improve  gold  work  in  tiie  proximal  cavities  of  the 
anterior  teeth  by  a  method  which  practically  does  away  with  cohesive 
gold,  the  author  offers  the  anterior  teeth  device. 

Fig.  281  shows  the  device  enlarged,  as  it  appears  before  being  placed 
in  position  about  the  teeth,  and  with  the  lower  part  shown  in  .section. 
The  arms  at  a  and  b  project  through  the  loops  formed  on  the  ends  of  the 
metallic  riblion  d,  the  thickness  of  which  is  j^qq  of  an  inch,  and  which 
may  be  passed  between  teeth  of  rigid  contact.  The  parts  a  and  b  are 
separable,  and  when  the  tension  screw  c  is  turned  in,  the  arm  b  is  ex- 
tended, which  puts  the  ribbon  d  under  tension. 

Fig.  282  shows  a  lingual  view  of  four  incisors  with  the  matrix  ribbon 
in  position  before  it  has  been  adapted  at  the  incisal  edge.  Fig.  283  shows 
the  ribbon  crimped  and  soldered,  which  adapts  it  clo.sely  to  the  tooth 
at  the  inci.sal  edge,  and  to  the  surface  of  the  tooth  beneath  the  ribbon. 

Fig.  284  presents  a  labial  view  with  the  device  in  position,  and  shows 
how  cavities  which  extend  through  and  open  on  the  lingual  face  of  the 
tooth  may  be  floored  and  brought  into  smiple  form. 


MATRIX  FOR  THE  ANTERIOR  TEETH 


257 


Fit!;'.  2Sr)  shows  a  mcjuis  of  takiiio-  up  slack  in  the  rihhon,  if  this  slioiild 
Ix'coino  necessary,  by  slij)j)in(j^  the  shlted  arm  astride  of  the  rihhon,  as 
shown  in  this  figure.  By  this  means,  if  at  any  time  the  tension  screw 
should  he  rnn  in  to  its  limit,  additional  tension  can  be  obtained  without 


removing  the  ribbon. 


I'ki.  282 


The  mct.illic  ribbon  in  position  before 
crimping. 

Fici.  284 


The  holder  applied  for  tensioning  the  ribljon 


Fir,.  2SG 


Application  of  the  ribbon  pressing  tiic  left 
central  forward. 

Fig.  288 


Application  of  the  holder  pressing  the  lower 
right  central  forward. 


Fifi.  283 


The  metallic  ribbon   adapted  to  tooth  after 
crimping. 

Fig.  285 


The  holder  applied  for  taking  up  slack  in 
the  ribbon. 

Fig.  287 


Application  of  the  metallic  ribbon  between 
the  anterior  lower  teeth. 

Fig.  289 


E,  cervical,  /•',  incisal,  G,  lingual,  //,  labial 
subdivision  of  proximal  incisor  filling. 


Fig.  286  is  a  view  showing  the  cutting  edge  of  the  teeth  and  the  crimp 
of  the  metallic  ribbon. 

Fig.  287  is  an  application  of  the  ribbon  to  the  lower  incisors.     It  must 
ordinarily  be  placed  between  the  teeth  before  applying  the  holder.    Fig. 
288  shows  the  holder  in  position. 
17 


258  USE  OF  THE  MATRIX   IN  FILLING  OI'ERATIONS 


FILLING  PROXIMAL  CAVITIES  WITH  COHESIVE  AND  NON- 
COHESIVE  GOLD  WITH  ANTERIOR  TEETH  MATRIX 

Fig.  289  shows  a  proximal  cavity  in  a  central  incisor  three-fourths 
filled  by  the  aid  of  tiie  niati'ix,  after  which  tlie  matrix  is  removed.  The 
subcHvisions  of  the  fining,  lettered  e,  f,  and  G,  are  made  of  soft  gold, 
leaving  the  space  marked  h  to  be  filled  with  cohesive  gold.  The  pro- 
cedure Avhich  best  accomplishes  this  is  as  follows:  If  the  cavity  be  a  large 
one,  take  a  No.  3  or  4  soft-gold  cylinder  and  doul)le  it  upon  itself  and 
again  crosswise,  making  a  firm  cushion.  Let  this  cushion  be  large 
enough  to  squeeze  into  place.  Take  a  foot-shaped  plugger  with  light 
serrations,  Nos.  257,  258,  or  259,  Fig.  291 — whatever  size  of  this  form 
best  suits  the  case — and  press  this  first  cushion  into  the  undercuts  of  the 
cavity  at  e.  After  settling  it  by  hand  pressure,  take  a  suitable  foot- 
shaped  plugger.  No.  257  or  258  answers  well,  in  the  automatic  mallet, 
and,  while  holding  down  at  the  lingual  side  of  the  cushion,  mallet  the 
other,  after  which  change  the  instruments  al)out,  and  mallet  the  labial 
side.  After  this  is  done,  treat  the  opposite  end  of  the  cavity  at  F  in  the 
same  way,  only  the  cushion  going  into  this  subdivision  may  occasionally 
have  to  be  drawn  into  place  with  the  throat  of  the  instrument.  When 
the  F  subdivision  is  condensed,  use  a  No.  2  cylinder  folded  once  upon 
itself,  and  introduce  end-wise  at  G,  which  when  condensed  keys  E  and  P 
in  place.  If  the  cavity  be  a  large  one  it  will  require  two  of  the  No.  2 
cylinders,  and  in  some  cases  three,  to  bring  this  part  of  the  filling  to  the 
centre  of  the  cavity,  which  is  necessary  in  order  to  securely  brace  e  and 
F  in  place. 

The  author  cautions  against  using  small  soft  cylinders  with  which  to 
make  a  key-block,  because  when  condensed  they  do  not  build  up  high 
enough  to  obtain  the  necessary  lateral  bearing  against  blocks  E  and  f  to 
hold  firmly  in  place.  Neither  should  cohesive  gold  in  any  form  be  used 
here. 

It  will  be  observed  from  the  lines  of  the  cavity  division  in  Fig.  289 
that  the  cavity  is  to  be  filled  from  the  labial  side,  and  that  it  extends 
through  into  the  lingual  face  of  the  tooth,  also  that  the  matrix  ribbon, 
which  has  been  removed  to  show  the  plan  of  the  filling,  envelops  and 
embraces  the  tooth  in  such  manner  as  to  floor  the  lingual  portion  of  the 
cavity,  as  may  be  seen  in  Figs.  284,  285,  287,  and  288. 

The  action  of  the  device  not  only  moves  the  tooth  forward  to  be  filled 
as  seen  in  Fig.  286,  so  that  it  may  be  got  at  easily,  but  transforms  a  dif- 
ficult cavity  into  one  of  easy,  simple  form. 

In  the  instances  where  the  opening  of  the  cavity  is  toward  the  lingual 
aspect  with  a  labial  wall  to  be  preserved,  the  device  operates  with  as 
much  favor  in  filling  from  the  lingual  as  from  the  la})ial  aspect — see 
Figs.  283  and  286.     In  these  figures  the  action  of  the  device  will  be 


PIA'CUERS  FOR  MATRIX    WORK  2.39 

so(Mi  to  move  forward   (he  left  eeiitral  and  depress  the  rin;ht  central  and 
left  lateral. 

When  the  fillino-  is  made  from  the  lingual  aspect,  the  lines  of  the  sub- 
divisions of  the  filling-,  Fig.  2.S<),  would  be  reversed,  and  the  key-block 
H  would  be  placed  in  the  position  of  g. 

PLUGGERS  FOR  MATRIX  WORK 

The  point  of  a  plugger  is  not  all  of  its  efficiency.  The  handle  may 
materially  enhance  or  handicap  its  performance,  and  the  average  student, 
unless  guided  in  the  selection  of  points  and  handles,  is  apt  to  get  together 
in  the  selection  of  excavators  and  pluggers  an  incongruous  combination, 
much  of  which  will  prove  unsuited  and  unfitted  for  anything  he  is  called 
on  to  do. 

Some  of  the  forms  of  pluggers  here  suggested  for  matrix  work  may 
be  found  in  the  student's  case.  All  included  in  the  list  of  Fig.  291  are 
regarded  as  cohesive  gold  instruments,  but  several  of  these  forms  are  ill 
adapted  to  that  work  and  well  adapted  for  soft  gold.  Many  of  the  forms 
of  instruments  included  in  sets  of  soft  gold  pluggers  cannot  be  utilized 
in  the  execution  of  the  soft-gold  part  of  the  matrix  fillings  set  forth  in 
this  chapter;  and  to  assist  the  student  in  knowing  which  instruments 
shall  be  used  to  manipulate  the  cohesive,  and  which  the  soft,  and  the 
handles  best  suited  to  them,  are  pointed  out  and  explanation  of  their 
uses  made. 

The  Handles  Adapted  to  the  Pluggers.^— Nos.  7,8, 10,  18,  115, 116,  117, 
118,  207,  and  208  should  be  placed  in  cone-socket  handles  Nos.  4  or  5, 
Fig.  290,  according  as  the  shank  of  the  plugger  point  is  small  or  large. 
These  handles  can  be  used  for  hand  pressure,  but  are  designed  especially 
for  the  hand  mallet. 

Nos.  174,  175,  248,  and  250  should  be  placed  in  the  cone-socket 
handles  Nos.  2  or  3,  Fig.  290,  according  as  the  shank  of  the  plugger 
point  is  small  or  large. 

Nos.  257,  258,  and  259  should  be  placed  in  the  rubber  handles  No.  10 
or  10a,  Fig.  290,  according  as  the  shank  of  the  plugger  point  is  small 
or  large. 

The  Uses  of  the  Several  Pluggers.— Nos.  7,  8,  115,  116,  1 17,  118,  and  207, 
Fig.  291,  are  for  cohesive  gold,  and  may  be  made  to  answer  the  needs  of 
this  work  in  connection  with  matrix  fillings. 

No.  60  Family  Brown  plugger  point,  for  cohesive  gold,  is  of  universal 
application,  and  is  best  used  in  the  electric  or  the  engine  mallet. 

Nos.  174  and  175,  Fig.  291,  are  assistant  pluggers,  used  to  hold  dow^n 
when  malleting,  and  may  be  used  for  packing  cushions  in  the  cervico- 
occlusal  column  of  molar  and  bicuspid  matrix  fillings. 

1  The  haodles,  pluggers,  and  numbers  of  same  are  taken  from  the  revised  lists  of  the  S.  S.  White 
Dental  Manufacturing  Company. 


2G0 


USE  OF   THE  MATRIX   J .\   FlLLlXd  OI'ERATIOX.S 


Nos.  24S  and  250,  l^g.  291,  aiv  for  soft  gold,  jiiid  used  for  i)liuiiig  and 
compre.ssing  the  cnsliions  into  tiie  snlxlivisions  E  and  F,  Fig.  289,  of 
the  smaller  class  of  :i])i)r()xinial  incisc^r  cavities. 


Fig.  290 


Fio.  291 


7  8     10    lo      llo  116  117  118 


!  I     i  I     1         t     i  i       II 

174    175  207   208  248   250   257   258   259 

Condensed  set  of  pluggers. 


3  4  5  10 

Handles  for  cone-socket  points. 


10a 


Nos.  257,  258,  and  259,  Fig.  291,  are  for  compressing  the  cnshions 
into  subdivisions  e  and  f,  Fig.  289,  of  the  larger  class  of  approximal 
incisor  cavities.  The  square  corners  at  the  toe  of  these  forms  should  be 
rounded  oft. 


A   MATRIX  AUXILIARY 


2G1 


Nos.  10,  IS,  20S,  24S,  and  250,  Fi<>-.  201,  are  for  settlinf^r  and  inallet- 
ing  soft-gold  c'lLsiiions  in  the  cervico-occlusal  coluinii  of  molars  and 
bicuspids  (see  Figs.  249,  252,  and  253),  and  for  carrying  down  and 
malleting  the  suixlivision  g,  Fig.  2S0,  and  fillings  of  this  class. 

A  MATRIX  AUXILIARY 

Dr.  Alfred  P.  T.ee,  of  Philadelphia,  has  devised  a  simple  and  practi- 
cable method  of  overcoming  the  difficulty  often  experienced  in  adapting 
the  matrix  to  a  })roximo-occlusal  cavity  when  the  cervical  portion  of 
the  missing  wall  presents  a  concave  surface,  due  to  the  tendency  of 
the  roots  to  bifurcate. 

By  the  use  of  sheet  copper,  not  more  than  ttmT'o  of  an  inch  in  thick- 
ness, in  conjunction  with  the  Ivory  or  similar  matrix,  an  appliance  is 
made  which  when  removed  after  the  filling  has  been  inserted  will  be 
found  to  have  kept  the  filling  the  desired  shape,  leaving  no  overhanging 
portions  at  the  cervix  to  trim  away. 


Fig.  292 


Fig.  293 


Fig.  294 


Transverse  section  of  tooth  at 
a  point  near  cervical  border  of 
cavity.  Outer  line  showing  cop- 
per matrix  in  position.  Dotted 
line  represents  degree  of  contour 
supplied  with  hard  wax  or  solder. 


Both  matrices  in  position 
on  tooth  crown. 


Shows  copper  plate  with 
cervical  depression  filled 
with  soft  solder  and  applied 
to  cavity  before  adjustment 
of  outer  matrix. 


A  piece  of  thoroughly  annealed  copper  plate,  large  enough  to  cover 
the  proximal  portion  of  the  cavity  and  extend,  say  one-eighth  of  an 
inch  beyond  the  buccal  and  lingual  margins,  is  pressed  with  cotton  or 
bibulous  paper  pellets  to  conform  to  the  concave  root  periphery  at 
the  cervix.  The  copper  is  then  carefully  removed  and,  if  the  cavity 
be  for  amalgam,  the  depression  in  die  copper  representing  the  cervical 
concavity  is  filled  with  hard  wax  until  a  convexity  is  obtained;  the  copper 
plate  is  then  placed  in  position,  and  around  it  a  steel  matrix  is  adjusted, 
and  when  fully  tightened  the  free  edge  of  tlie  copper  is  l)urnished  against 
the  steel. 

^Vllen  gold  is  to  be  inserted  it  is  necessary  to  use  something  more 
stable  than  the  hard  wax,  therefore  the  concave  surface  at  the  cervical 
margin  of  the  copper  plate  is  touched  with  zinc  chlorid,  and  over  the 
alcohol  or  Bunsen  flame  soft  solder  is  flow^ed  into  the  depression.  Any 
surplus  may  be  trimmed  off  with  a  disk. 


CHAPTER    XI 

PLASTICS 

By  MARCUS  L.  WARD,  D.D.Sc. 

NATURE  OF  AMALGAM 

An  amalgam  is  a  combination  of  two  or  more  metals,  one  of  which 
is  mercury,  and  may  be  either  a  liquid,  solid,  or  semisolid.  The  term 
amalgam  is  derived  from  the  Greek  malagma,  from  mallasso,  to  soften, 
the  presence  of  mercury  lowering  the  melting  point  of  such  a  mixture. 

The  term  "metal"  indicates  a  certain  number  of  chemical  elements 
which  in  the  present  state  of  chemical  science  are  undecomposable 
and  possess  certain  well-defined  characters  in  common,  such  as  opacity, 
luster,  conductivity,  high  specific  gravity,  and  plasticity  or  capability  of 
being  drawn,  squeezed,  or  hammered  without  loss  of  continuity. 

Comparatively  few  of  the  metals  possess  characters  such  as  render 
them  suitable  to  be  employed  alone  by  manufacturers,  although  there 
are  many  applications  for  most  of  them  when  two  or  more  are  caused 
permanently  to  unite.  The  compound  thus  formed  l)y  the  union  of  two 
or  more  metals  is  termed  an  alloy.  The  word  alloy  is  believed  to  be 
derived  from  the  French  aloi  (the  metal  of  the  standard  coin),  a  con- 
traction of  a  la  hi  (according  to  the  law).  An  amalgam,  then,  represents 
that  class  of  alloys  which  contain  mercury.  The  agencies  by  which  the 
union  of  metals  is  affected  are  heat,  electrodeposition,  pressure  at  ordin- 
ary temperatures,  and  by  dissolving  one  or  more  metals  which  exist  in 
a  solid  state  at  ordinary  temperatures  in  a  metal  which  exists  in  a  lifjuid 
state  at  ordinary  temperature. 

Practically  all  alloys,  except  dental  amalgam  alloys,  are  formed 
through  the  agency  of  heat,  but  certain  soft  metals,  such  as  lead,  tin, 
bismuth,  cadmium,  etc.,  have  been  shown  by  Professor  Spring,  of  Liege, 
to  form  true  alloys  under  pressure  and  absence  of  heat.  This  process, 
however,  has  not  as  yet  found  application  much  l)eyond  the  lal)oratories, 
where  it  is  used  to  demonstrate  that  there  is  actual  union  between  the 
particles  of  different  metals  in  the  cold  when  they  are  brought  into 
intimate  contact.  Certain  alloys,  such  as  gold  and  copper,  or  copper 
and  zinc,  may  be  prepared  by  electrodeposition.  Several  alloys  are 
prepared  by  this  method  on  a  large  scale. 

The  utility  of  dental  amalgam  alloys  depends  largely  upon  the  property 
which  mercury  has  of  dissolving  most  other  metals  to  the  point  of  satu- 
ration, forming  alloys  which,  when  allowed  to  stand  for  some  time,  harden 
(262) 


NATURE  OF  AMALGAM  263 

or  set.  Thishardeniiioorsettiiiir  |)r()c(vss  is  jji-obahly  due  to  tlie  formation 
of  a  ehemical  eompoiiiid  between  the  mercury  and  one  or  more  of  tlie 
metals  used  in  combination  with  it.  The  mass  thus  formed  of  metal  or 
alloy  in  combination  with  mercury  cannot  i)e  re(>;arded,  however,  as  a  true 
amali>'am,  for  Matthiessen  lias  pointed  out  that  such  a  mixture  may  be 
either  a  chemical  compound,  a  solidified  solution  of  one  metal  in  another, 
a  meciuinical  mixture,  or  a  solidified  solution  or  mixture  of  all  three. 

There  are  some  phenomena,  such  as  change  in  volume,  change  in 
strength,  and  evolution  of  heat,  that  lead  to  the  belief  that  definite  com- 
pounds do  exist  in  definite  proportions  by  weight.  Most  of  the  metals 
usetl  to  form  the  alloy  which  is  combined  with  mercury  to  form  an  amal- 
gam are  capable  of  existing  in  a  state  of  chemical  combination,  although 
they  are  subject  to  Matthiessen's  classification,  and  are  usually  united  by 
feeble  affinities,  for  it  is  necessary,  in  order  to  produce  energetic  union, 
that  the  constituents  exhibit  much  dissimilarity  in  properties.  There  is 
little  doubt  that  these  metals  do  unite  in  definite  proportions,  although  it  is 
difficult  to  obtain  them  as  such,  since  the  compounds  thus  formed  dissolve 
in  all  proportions  in  the  melted  metals  from  which  they  do  not  differ  very 
widely  in  their  melting  points.  For  these  reasons  it  has  been  questioned 
whether  not  only  amalgams,  but  any  alloy  were  a  true  chemical  compound. 

Definite  compounds  have  been  proved  to  exist,  however,  in  both 
the  native  and  artificial  state.  Hiorns  gives  a  good  illustration  of  a 
chemical  compound  between  two  metals  in  the  alloy  of  copper  and  tin 
which  may  be  represented  by  the  formula  SnCuj,  containing  38.4  parts 
of  tin  and  61.6  parts  of  copper.^  A  well-known  native  chemical  compound 
of  two  metals  is  represented  by  silver  and  mercury,  which  are  found  crys- 
tallized together  in  the  follow^ing  porportions:  (AggHg,  or  AggHgg)  and 
■(Ag3Hge).^ 

Under  the  term  solution  of  one  metal  in  another,  we  understand  one 
like  ether  and  alcohol,  or  any  two  substances  which  may  be  mixed  in  all 
proportions  and  will  not  separate  into  layers  by  standing.  Solidified 
solution  would  indicate  the  solidification  of  a  perfectly  homogeneous  dif- 
fusion of  one  body  in  another  and  has  been  represented  by  glass,  which  is 
formed  in  the  liquid  state  at  a  high  temperature  and  solidifies  on  cooling 
without  separation  of  the  different  silicates.  Hiorns  quotes  Mendeleef  as 
saying  that  solutions  are  fluid,  unstable,  definite  chemical  compounds 
in  a  state  of  dissociation,  and  that  of  such  a  kind  are  most  metallic  alloys. 
They  have  been  considered  in  the  Journal  of  the  Chemical  Society  as 
solidified  solutions  of  metals  which  contain  definite  compounds  in  excess 
of  one  of  the  constituent  metals.  The  subject  of  solution  apparently 
has  a  most  important  application  in  the  production  of  dental  amalgams. 

In  the  same  manner  that  water  dissolves  saline  substances,  alcohol 
dissolves  resins,  ether  dissolves  fats,  etc.,  mercury  dissolves  most  metals. 
A  very  interesting  phenomenon  to  observe  in  this  connection  is  the  manner 

■  Hiorns,  Mixed  Metals  or  Metallic  Alloys. 


204  PLASTICS 

ill  which  most  solvents  act  upon  sohds  (^Iliorns).  As  a  rule,  the  dis- 
solving power  of  each  liquid  is  confined  to  a  certain  class  of  solids.  It 
is  also  a  general  rule  that  the  solubility  of  a  body  in  any  medium  de- 
pends on  a  similarity  in  the  constitution  of  the  body  and  the  solvent. 

When  a  li(|uid  has  dissolved  all  of  a  solid  that  it  is  capable  of  retaining 
at  a  given  temperature,  it  is  said  to  have  become  saturated;  but  even  if 
it  be  saturated  with  one  solid  it  may  yet  take  up  another,  and  oftentimes 
the  solvent  power  is  thereby  increased. 

A  general  survey  of  the  literature  reveals  a  lack  of  knowledge  of  the 
peculiarities  of  solutions,  and  appears  to  explain  largely  why  so  much 
importance  has  i)een  attached  to  the  kind  of  receptacle  to  be  used  for 
mixing  alloys  with  mercury,  and  the  manner  of  incorporating  them. 

It  appears  important  that  the  subjects  of  crystalli/ation  and  diffu- 
sion should  be  considered  in  connection  witli  the  formation  of  dental 
amalgams,  since  they  are  both  closely  allied  with  solutions.  The  placing 
into  solution  in  mercury  of  metals  or  alloys,  the  subsequent  setting 
(crystallization)  of  the  mass,  and  a  final  complete  diffusion  of  these 
constituents  seems  to  l)e  controlled  by  the  same  agencies  as  are  other 
chemical  phenomena.  External  heat,  for  example,  influences  these 
phenomena  a  great  deal,  it  being  considered  that  a  rise  in  temperature 
of  10°  C.  will  double  the  velocity  of  75  per  cent,  of  all  chemical  reactions. 

The  conversion  of  chemical  energy  into  heat  may  also  influence  these 
phenomena.  The  condition  of  contact  between  the  mercury  and  the 
metal  or  alloy  upon  which  it  is  reacting  will  likewise  have  its  influence 
upon  the  above  phenomena.  The  internal  movements  of  the  compo- 
nent particles  of  the  mass  may  facilitate  diffusion,  solution,  and  chemical 
change.  In  fact,  about  the  only  difference  that  appears  between  dental 
amalgams  and  a  majority  of  chemical  compounds  is  that  the  metals  are 
united  by  very  feeble  affinities,  and  there  exists  a  great  tendency  for  the 
amalgam  to  possess  the  properties  of  its  constituents.  There  are  some 
cases  where  a  combination  is  totally  different  from  either  constituent, 
but  the  general  effect  is  for  each  constituent  metal  to  maintain  its  identity. 

The  advantage  of  alloying  metals  together  seems  to  be  to  asseml)le  in 
one  compound  a  number  of  properties  which  could  not  be  found  in  any 
one  element.  Through  the  work  of  such  men  as  Flagg  and  Black,  silver, 
tin,  copper,  zinc,  and  occasionally  gold  in  small  quantities  have  been 
found  to  possess  more  desirable  and  less  undesirable  properties  than 
any  other  equal  number  of  metals.  Since  the  work  of  Dr.  Black*  two 
new  but  distinct  classes  of  alloy  have  appeared  as  the  principal  products 
of  nearly  all  leading  manufacturers.  One  of  them  contains  from  (>5 
to  68  per  cent,  of  silver,  2()  to  28  per  cent,  of  tin,  3  to  4.5  per  cent,  of 
copper,  and  1  to  2.5  per  cent,  of  zinc.  The  other  contains  from  43  to  48 
per  cent,  of  silver,  48  to  58  per  cent,  of  tin,  and  1  to  2  per  cent,  of  zinc. 

'  See  Dental  Cosmos,  vol.s.  xxxvii  and  xxxviii. 


NATLUiK  OF  AMALCIAM 


2()5 


The  first  chi.ss  is  known  as  high  percentage  silver  alloys,  fjuiek  setting 
alloys,  and  lilack's  alloys,  the  three  names  being  synonymous.  The 
second  class  is  known  as  low  percentage  silver  alloys,  slow  setting  alloys, 
and  plastic  alloys.  Both  classes  seem  to  have  grown  out  of  Black's  work, 
the  latter  class  undoubtedly  wiUi  his  disapproval. 

ExiiiuiT,  C'i).Mi'(>snu)N,  AND  Physical  Pkopeutiks  of  Unmouifikd  HiT.VKii-TiN 

Alloys. 


r'oni.ul: 

I'. 

Plow 

Per  cent. 

Shrink 

>      Kxpaii- 

CruKhiiig 

Silver. 

liii. 

prepared. 

of  mercury. 

age. 

sioii. 

Flow. 

stre.ss. 

40 

GO 

Fresh-cut 

45.78 

6 

7 

40.15 

178 

40 

60 

Annealed 

34.14 

9 

3 

44.60 

186 

45 

55 

Fresh-cut 

49.52 

4 

8 

25.46 

188 

45 

55 

Annealed 

32.13 

7-11 

1 

28.57 

222 

50 

50 

Fresh-cut 

51.18 

2 

2-4 

22.16 

232 

50 

50 

Annealed 

37.58 

10-17 

0-1 

21.03 

245 

55 

45 

l''resh-cut 

51.62 

0-2 

0-2 

19.66 

245 

55 

45 

Annealed 

40.11 

10-18 

0 

17,53 

276 

60 

40 

Fresh-cut 

52.00 

1-3 

0 

9.06 

239 

60 

40 

Annealed 

39.80 

10-17 

0 

14.10 

297 

65 

35 

Fresh-cut 

52.00 

0 

1-5 

3.67 

290 

65 

35 

Annealed 

33.00 

6-10 

0 

5.00 

335 

70 

30 

Fresh-cut 

55.00 

0 

14-20 

3.45 

316 

70 

30 

Annealed 

40.00 

5-7 

0 

4.67 

375 

72.5 

27.5 

Fresh-cut 

55.00 

0 

28-42 

3.92 

350 

72.5 

27.5 

Annealed 

45.00 

0-3 

0-4 

3.76 

4.^0 

75 

25 

Fresh-cut 

55.00 

0 

40-60 

5.64 

258 

75 

25 

Annealed 

50.00 

0 

6-8 

5.40 

300 

Exhibit,  Composition,  and  Phy'sical  Properties  of  Modified  Silver-tin 

Alloys. 


Formul 

oe. 

How 

Per  cent. 

Shrink- 

■  Expan 

- 

Crushing 

Modifying  metal 

.   Silver. 

Tin. 

prepared. 

of  mercury 

.     age. 

sion. 

Flow. 

.stress. 

None 

65 

35 

Fresh-cut 

52 .  33 

0 

1 

3.67 

290 

None 

65 

35 

Annealed 

33.00 

10 

0 

5.00 

335 

None 

66.75 

33.25 

Fresh-cut 

51 .  52 

0 

4 

3.35 

329 

None 

66.75 

33.25 

Annealed 

33.53 

7 

0 

5.06 

380 

Gold  5 

61.75 

33.25 

Fresh-cut 

47.56 

0 

1 

4.62 

330 

Gold  5 

61.75 

33.25 

Annealed 

30.35 

7 

0 

6.07 

395 

Platinum  5 

61.75 

33.25 

Fresh-cut 

51.87 

0 

9 

9.68 

200-273 

Platinum  5 

61.75 

33.25 

Annealed 

37.33 

7 

0 

8.20 

2.50-352 

Copper  5 

61.75 

33.25 

Fresh-cut 

53.65 

0 

23 

2.38 

300-343 

Copper  5 

61.75 

33.25 

Annealed 

35.60 

5 

0 

3.50 

416-450 

Zinc  5 

61.75 

33.25 

Fresh-cut 

56.65 

0 

68 

1.83 

200-290 

Zinc  5 

61.75 

33.25 

Annealed 

40.65 

0 

9 

2.07 

250-345 

Bismuth  5 

61.75 

33.25 

Fresh-cut 

46.26 

0 

0 

4.78 

250-288 

Bismuth  5 

61.75 

33.25 

Annealed 

23.67 

6 

0 

5.58 

308 

Cadmium  5 

61.75 

33.25 

Fresh-cut 

57.57 

0 

100 

6.40 

225 

Cadmium  5 

61.75 

33.25 

Annealed 

47.25 

0 

5 

3.54 

290 

LeatI  5 

61.75 

33.25 

Fresh-cut 

44.17 

0 

1 

4.88 

290 

Lead  5 

61 .  75 

33.25 

Annealed 

32.76 

10 

0 

7.18 

276 

Aluminum  5 

61.75 

33.25 

Fresh-cut 

65.00 

0 

445' 

Aluminum  1 

64.5 

34.5 

Fresh-cut 

46.98 

0 

166 

12.60 

198 

Aluminum  1 

64.5 

34.5 

Annealed 

38.26 

0 

48 

17.90 

213 

The  first  class  seems  to  be  based  upon  the  properties  of  72^  per  cent, 
of  silver  and  21\  per  cent,  of  tin,  the  most  important  of  which  is  the 
small  amount  of  shrinkage  which  takes  place  when  this  alloy  is  con- 
verted into  amalgam.  The  second  class  seems  to  be  based  upon  the 
dual  movement  of  50  per  cent,  of  silver  and  50  per  cent,  of  tin,  which  by 


200  PLASTICS 

referrinj;'  to  Dr.  Black's  cliarts  is  seen  to  l»e  only  2  points.  Besides 
the  two  principal  cla.sses  of  alloys  mentioned,  there  are  in  the  market 
manv  of  the  alloys  made  and  nsed  previons  to  Dr.  Black's  work. 

Townsend's  original  alloy  of  silver  42  per  cent,  and  tin  58  per  cent,  is 
still  used  by  some. 

Flagtr's  alloys,  especially  the  one  containin<i;  silver  GO  per  cent.,  tin  .35  per 
cent.,  and  copper  5  per  cent.,  are  still  in  the  market  and  used  by  some. 

There  are  a  dozen  or  more  alloys  made  to  supj^ly  the  varied  demands 
of  the  profession.  Some  of  them  have  one  or  more  j)roniinent  (|ualities, 
but,  as  a  rule,  they  are  not  free  from  a  reduction  in  volume  at  the  time 
of  and  subsequent  to  insertion,  nor  do  they  seem  to  be  based  upon  any 
particular  principle,  as  are  the  two  classes  which  have  resulted  from 
Blac-k's  work.  Inasmuch  as  these  alloys  are  also  composed  of  silver, 
tin,  copper,  zinc,  and  occasionally  gold,  they  are  subject  to  the  same 
consideration  as  far  as  physical  and  chemical  properties  are  concerned. 
It  would  seem  that  dental  amalgams  can  best  l)e  understood  by  di\iding 
them  into  the  two  classes  spoken  of  as  high  percentage  silver  alloys  and 
low  percentage  silver  alloys.  The  difference  between  the  two  can  prob- 
ably be  best  represented  l)y  first  considering  the  most  important  proper- 
ties of  each  constituent. 

Silver  unites  with  mercury  in  definite  proportions,  and  through  its  com- 
paratively strong  affinity  for  mercury  and  its  large  proportions  it  largely 
controls  the  setting.  It  tarnishes  quite  readily  in  sulphuretted  hydro- 
gen and  soluble  sulphids.  It  increases  in  volume  when  amalgamated. 
It  increases  edge  strength,  lessens  the  flow,  and  because  of  its  great 
tendency  to  crystallize  and  its  property  of  going  into  solution  in  mer- 
cury slowly  at  ordinary  temperatures  it  causes  the  alloy  to  amalgamate 
tardily  and  the  mass  to  work  hard. 

Tin  unites  with  mercury  in  all  proportions  at  all  temperatures,  forming 
a  weak  crystalline  compound.  It  retards  the  setting,  decreases  in  vol- 
ume when  amalgamated,  decreases  edge  strength,  increases  the  flow, 
and  imparts  plasticity,  thus  causing  the  mass  to  work  easily. 

Copper  unites  with  mercury  with  flifficulty  at  ordinary  temperatures, 
although  in  definite  proportions  it  generally  hastens  the  setting,  increases 
edge  strength,  lessens  flow,  does  not  change  appreciably  in  volume  when 
amalgamated,  and  is  easily  tarnished  by  sulphuretted  hydrogen  and 
soluble  sulphids. 

Zinc  unites  with  mercury  easily  and  in  definite  proportions,  increases 
in  volume  when  amalgamated,  hastens  the  setting,  increases  edge 
strength,  lessens  flow,  improves  color,  and  imparts  a  peculiar  smoothness 
to  the  mass  during  amalgamation. 

Gold  when  melted  with  the  other  constituents,  as  most  of  the  present 
alloys  are  made,  adds  almost  no  desirable  properties  and  adds  one  or 
two  undesirable  properties.  It  adds  a  little  to  the  color  and  makes  a  very 
tough  amalgam,  but  it  imparts  a  peculiar  pasty  springiness  which  makes 


NATURE  OF  AMALGAM  207 

it  (lidicult  to  pack.  There  are  some  possibilities  in  the  use  of  ^old  in 
small  (juantities,  however,  that  are  not  t'nlly  developed  and  which  look 
promising. 

From  the  nature  of  metallic  alloys  we  may  assume  that  certain  pro- 
portions of  these  constituents  enter  into  combination  and  other  portions 
are  simply  in  a  state  of  mixture  or  solution.  From  the  similarity  of  the 
metals  we  may  assume  that  energetic  union  has  not  taken  place,  and, 
as  a  result,  the  portions  united  chemically  are  not  expected  to  have 
properties  diverging  widely  from  their  constituents. 

Since  solutions  and  mixtiu'es  generally  possess  the  properties  of  their 
constituents,  we  would  expect  a  compound  composed  of  these  metals 
to  be  the  sum  of  the  properties  of  its  constituents.  Such  seems  to  be  the 
case  with  these  alloys.  A  point  to  be  observed  in  the  consideration  of 
these  alloys  is  that  one  or  two  metals  are  used  as  the  base  of  the  alloy 
and  the  others  as  modifiers,  the  attempt  being  made  to  add  to  the  prop- 
erties of  the  basal  constituents  some  of  the  properties  of  other  constituents. 

A  consideration  of  the  alloys  now  in  use,  with  one  or  two  exceptions, 
shows  that  the  selection  of  these  metals  and  the  proportions  of  each 
has  been  made  with  reference  to  their  physical  behavior,  special 
emphasis  being  placed  upon  decrease  in  volume,  color,  and  strength. 
Fenchel,^  however,  has  for  some  time  been  studying  amalgams  from 
a  different  point  of  view.  He  has  taken  a  break  in  the  cooling  curve  of  any 
liquid  (including  melted  metals)  to  indicate  a  change  in  physical  consti- 
tution, and  from  this  traced  the  crystallizing  curve  of  some  of  these 
alloys  in  increasing  proportions  to  each  other.  He  has  studied  the  struc- 
ture of  these  alloys  microscopically  as  well  as  with  reference  to  alteration 
in  form,  resistance-  to  stress,  specific  gravity,  and  electromotive  force  of 
currents  set  up  in  the  mouth  by  different  metals,  all  of  which  forms  a 
very  valuable  part  of  scientific  literature.  Fenchel's^  work  may  be  said  to 
follow  more  closely  the  chemical  phases  of  alloys  than  the  physical  ones, 
while  the  work  of  others  seems  to  be  devoted  largely  to  the  physical 
properties. 

It  would  appear  that  a  clear  understanding  of  the  physical  behavior 
of  these  alloys  cannot  be  had  without  at  least  a  working  knowledge  of 
their  chemical  behavior.  For  the  present  however,  our  knowledge 
of  alloys  most  generally  adopted  (the  two  classes  mentioned)  is  con- 
fined largely  to  their  physical  behavior.  The  principal  difference  be- 
tween the  two  classes  of  alloys  should  be  obvious.  The  first,  with  more 
silver,  less  tin,  and  some  copper,  is  stronger,  more  stable  in  form,  more 
free  from  decrease  in  volume,  though  it  works  hard  and  sets  quickly. 
The  second,  with  its  high  percentage  of  tin,  low  percentage  of  silver,  and 
absence  of  copper  is  easier  to  amalgamate,  sets  slower,  and  is  a  little 
lighter  in  color.     These  two  classes  of  alloys  resemble  some  of  the  older 

'  Dental  Cosmos,  vol.  1,  p.  553,  and  vol.  li,  p.  1. 

-  For  a  study  of  Fenchel's  work  see  his  various  papers  in  the  Dental  Cosmos. 


2GS  PLASTICS 

as  well  as  niunv  of  the  newer  ones  by  havin<:;  some  properties  in  common. 
Contraction  and  expansion,  for  example,  seem  to  be  phenomena  accom- 
panvinij;  the  setting  of  dental  amali!:ams.  Dr.  J.  Foster  Fla<;<,f  and  the 
previous  workers  seemed  to  attribute  these  properties  largely  to  the  com- 
position of  the  alloy.  Dr.  Black  pointed  out  that  the  annealing  of  the 
cut  allov  increased  contraction.  It  has  been  pointed  out  that  the  per- 
centage of  mercury  used  during  amalgamation  had  its  infiueuce,  although 
it  can  hardly  be  regarded  as  a  cause  of  these  phenomena,  Imt  rather  a 
medium  to  facilitate  further  contraction  in  the  already  contracting  alloys 
and  expansion  in  already  expanding  alloys. 

The  writer  has  observed  that  the  order  of  melting  the  different  cf)n- 
stituents,  the  temperature  at  which  they  were  kept  molten,  the  time  that 
they  were  kept  molten,  the  temperature  at  which  they  were  cast,  and  the 
rapidity  of  cooling — each  could  be  made  to  have  its  influence  upon  the 
behavior  of  these  alloys.  He  has  also  noticed  that  the  size  and  shape 
of  the  alloy  filing  had  its  influence  upon  contraction  and  expansion. 
When  we  consider  that  alloys  containing  67  per  cent,  of  silver  and  .some 
copper  dissolve  tardily  in  mercury  at  ordinary  temperatures,  and  can 
only  be  made  to  form  a  little  true  amalgam  with  tiie  treatment  given 
by  dentists  during  amalgamation,  it  seems  entirely  within  reason  that 
the  "cut"  of  an  alloy  has  to  do  with  its  condition  of  contact,  and  often- 
times presents  a  typical  concrete  mass  with  the  undissolved  particles  of 
allov,  corresponding  to  the  bricks  in  the  wall,  and  the  true  amalgam 
formed  upon  the  surfaces  of  these  particles  corresponding  to  the  mortar. 

Jt  is  not  the  intention  of  the  writer  to  convey  the  idea  that  the  "cut" 
of  alloys  is  an  active  cause  of  contraction  or  expansion,  l)Ut  rather  a 
modifier  of  already  existing  contraction  or  expansion,  in  the  same  sense 
that  an  excess  of  mercury  is  a  modifier  of  these  movements.  That  the 
composition  of  alloys  has  to  do  flirectly  with  contraction  and  expan.sion 
seems  to  be  well  established. 

\\'ith  Flagg's  work  as  a  basis.  Black  seems  to  have  established  the  con- 
traction and  expansion  ranges  for  the  metals  generally  used  in  the 
production  of  dental  amalgams.  His  results  have  been  (|uesti()ued,  but 
it  would  seem  that  it  has  been  done  mostly  by  those  using  the  specific 
gravity  method  of  measuring  contraction  and  expansion  which  gives  the 
actual  volume,  while  Black's  measurements  were  taken  with  a  micrometer, 
which  gives  linear  measurements.  (See section  on  Methods  o^  Measuring 
Change  in  V^olume.) 

Black  has  assumed  that  of  all  the  properties  which  amalgams  possess, 
nothing  is  of  as  much  importance  as  freedom  from  contraction.  He  has 
regarded  it  as  imperative  that  there  must  be  absolute  freedom  from  con- 
traction and  only  a  minimum  of  expansion.  With  this  in  view,  as  will 
be  ofjserved  from  his  exhibit,  he  has  shown  that  a  minimum  of  contrac- 
tion, after  annealing,  took  place  with  72.5  per  cent,  silver  and  27.5  per 
cent,  of  tin.  Reference  to  the  foregoing  pages  shows  that  the  alloys  made 
after  his  plans  do  not  contain  this  amount  of  silver.     They  .show  that 


NATURE  OF  AMALGAM  209 

certain  ranj^es  are  adherod  to  which  seem  to  he  from  (io  jx-r  cent,  to 
(>S  j)er  cent.  The  reason  for  not  usini^  72.5  per  cent,  of  silver  seems  to 
he  tliat  a  suhstitution  of  ahout  5  per  cent,  of  coj)j)er  and  a  little  zinc  for 
an  equal  amount  of  silver  would  ^ive  the  same  minimum  contraction  and 
at  the  same  time  atld  some  of  the  desirahle  (|ualities  of  copper  and  zinc. 

Dental  literature  fails  to  show  that  any  definite  and  fixed  amount  of 
silver,  tin,  copper,  and  zinc  can  he  used  and  obtain  freedom  from  con- 
traction and  expansion.  Black  states/  in  describing  his  experiments 
with  the  silver-tin  alloys,  that  because  metals  of  a  chemically  pure 
nature  are  too  expensive  for  use  in  dentistry,  metals  of  a  less  degree  of 
])urity  are  used,  and  as  a  result  no  fixed  formula  is  good  for  general  use. 
His  exact  words  are:  "From  this  point  another  short  course  of  alloys 
only  0.5  per  cent.  a{)art  was  necessary  to  find  the  exact  balance  which 
would  produce  an  alloy  that  would  absolutely  lie  still  while  hardening. 
\Mien  this  was  found,  it  was  a  good  formula  for  that  batch  of  metals, 
but  not  for  another  batch,  for  the  purity  might  be  different,  and  the 
formula  for  each  new  batch  of  metals  had  to  be  found.  Therefore,  no 
fixed  formula  could  be  good  for  general  use.  If  it  were  possible  to  use 
chemically  pure  metals,  a  fixed  formula  would  be  possible,  but  such 
metals  would  be  too  expensive  for  use  in  dentistry." 

The  literature  from  many  of  the  leading  supply  houses  implies  that 
their  alloys  are  made  after  this  plan  suggested  by  Dr.  Black,  althougli 
some  claim  that  a  fixed  formula  is  the  basis  of  their  products.  A 
review  of  Fenchel's  recent  work,  and  the  earlier  work  of  Kirk  and 
Burchard,  each  of  whom  have  viewed  more  closely  the  chemical 
phases  of  alloys,  would  not  suggest  the  plan  ofVered  by  Dr.  Black.  The 
question,  "  Why  does  a  fixed  formula  not  give  a  definite  movement  during 
setting?"  has  been  asked  of  the  writer  so  many  times  by  teachers  and 
practitioners  alike  that  it  would  seem  as  though  the  plan  had  not  been 
understood  nor  accepted  generally  by  the  profession.  All  seem  agreed, 
however,  that  the  plan  gives  as  good  results  and  furnishes  us  with  as  good 
alloys  as  our  present  knowledge  of  the  subject  will  permit.  It  is  the 
manner  of  reaching  the  result  about  which  there  seems  to  be  a  differ- 
ence of  opinion.  The  plan  implies  more  than  the  mere  fact  that  impure 
metals  will  not  give  a  definite  movement.  It  implies  that  metals  cannot 
be  constantly  obtained  with  a  definite  grade  of  impurity,  for  if  a  metal 
contained  a  certain  impurity  in  certain  quantities  every  time  it  was  pur- 
chased, allowance  could  be  made  for  it  in  the  formula.  ^ 

While,  as  a  rule,  native  metals  are  not  to  be  relied  upon,  there  are 
some  instances  where  the  impurity  can  be  determined  and  allowance  be 
made  for  it  comparatively  easily.  It  is  quite  sweeping  in  its  scope, 
however,  to  say  that  refined  metals  cannot  be  obtained  which  are  quite 
uniform  in  their  impurities.  It  is  a  well-known  fact  that  the  character 
of  many  alloys  is  altered  by  the  manner  of  melting  and  casting. 

'  Operative  Dentistry,  vol.  ii,  310. 


270  PLASTICS 

Oftentimes  a  certain  property  of  a  ^aven  combination  may  he  lost 
or  obscured  by  repeated  remeltintj.  Most  metallurgists  are  aware  of 
the  difficulty  of  maintainin<ij  uniformity  in  an  alloy  during'  the  melting 
and  castin<^  process  which  is  least  for  two  metals  and  increases  when 
three  or  four  are  recjuired.  Since  practically  nothinjij  has  been  written 
by  Dr.  Black  and  those  adhering  to  his  plan  of  preparing  alloys  about 
this  most  difficult  of  all  metallurgical  processes,  nor  the  character  of 
these  impurities,  it  would  seem  probable  that  too  much  importance  had 
been  attached  to  the  presence  of  impure  metals  and  tc^o  little  to  the 
manner  of  preparing  them.  The  manner  of  preparing  these  alloys,  how- 
ever, should  l)e  regarded  as  a  modifier  rather  than  as  an  active  cause 
of  contraction  and  expansion.  With  this  in  view,  it  may  be  said  tiiat 
there  are  five  factors  which  influence  contraction  and  expansion,  viz. : 

Composition  of  alloy  (primary  cause). 

Manner  of  melting,  casting,  and  cooling  alloy  (secondary  cause). 

The  kind  of  cut  of  the  alloy  (secondary  cause). 

The  amount  of  annealing  of  cut  alloy  (secondary  cause). 

The  percentage  of  mercury  used  to  amalgamate  the  alloy  (secondary 
cause). 

A  sixth  factor  might  be  said  to  influence  these  movements,  viz.,  the 
manner  of  mixing  the  alloy  and  mercury,  although  it  seems  to  be  so  nearly 
synonymous  with  the  cut  of  the  alloy  that  it  may  be  left  out  of  consider- 
ation here.    (See  Section  on  Mixing  Alloys.) 

Annealing  of  Alloys. — Dr.  J.  Foster  Flagg  seems  to  have  been  the 
first  to  call  attention  to  the  fact  that  alloys  which  were  freshly  cut  behaved 
differently  when  amalgamated  than  the  same  alloys  did  after  they  had 
stood  for  some  time.  Dr.  Black  traced  the  phenomena  through  a  great 
number  of  experiments,  and  finally  arrived  at  the  conclusion  that  the  cut 
alloy  is  hardened  by  the  violence  in  cutting,  the  condition  thus  produced 
being  analogous  to  the  condition  of  the  same  metals  in  hammering.  His 
earlier  observations  led  to  the  belief  that  motion  brought  about  the  change, 
but  later  experiments  showed  that  it  had  no  influence.  Oxidation  was 
thought  to  be  a  factor,  but  was  finallv  eliminated  as  one  of  the  causes. 
After  a  great  many  experiments  it  was  proved  that  the  change  was  pro- 
duced by  annealing  or  tempering,  i.  p.,  a  molecular  alteration  of  the  cut 
alloy.  The  temperature  at  which  this  is  j)roduced  ranges  from  room 
temperature  upward.  If  the  alloy  be  subjected  to  room  temperature  for 
a  year  or  more,  ^he  same  effect  is  produced  as  when  it  is  subjected  to  a 
higher  temperature  for  a  shorter  time.  It  has  been  found  that  the  low 
temperature  and  longer  time  of  exposure  bring  about  a  more  complete 
annealing.  The  change  can  be  brought  about  by  subjecting  the  cut  alloy 
to  the  temperature  of  boiling  water  for  about  twenty  minutes,  although 
there  is  not  quite  the  same  quality  to  the  alloy  that  there  is  when  it  is 
subjected  to  a  temperature  of  120°  F.  for  from  two  days  to  a  week.  The 
amount  of  heat  recpiired  to  bring  about  the  change  is  not  the  same  for  all 


NATURE  OF  AMALGAM  271 

alloys,  iiltliough  each  I'orinula  seems  to  clijui<i;e  in  inaiiy  of  Its  })r()per(ies 
with  this  treatiiuMit.  That  tiiis  property  of  these  alloys  to  ehange  by 
so-called  "agin<;"  or  "annealing"  is  a  physical  phenomenon,  seems  to  be 
the  opinion  of  Dr.  Black*  and  of  Fenchel,^  but  whether  it  is  caused  by 
hardening  during  the  cutting  process,  as  suggested  by  Dr.  Black,  is  a 
question  worthy  of  consideration  by  those  interested  in  the  cause  of  this 
peculiarity. 

It  is  well  known  that  the  working  of  metals  forces  their  molecules  into 
unnatural  positions,  and  that  by  annealing  they  are  largely  restored  to 
their  normal  state.  But  it  is  also  well  known  that  the  rate  and  manner 
of  cooling  of  many  metals  may  preserve  in  some  cases  and  alter  in  others 
the  mode  of  existence  of  the  molecules  at  the  time  they  were  molten. 
It  is  also  worthy  of  note  in  this  connection  that  unequal  stresses  are 
set  up  in  some  castings  by  cooling  the  outer  layers  of  the  metal  much 
quicker  than  the  interior,  thereby  causing  a  compression  of  the  interior 
by  the  outer  layers. 

By  annealing,  which  is  the  reverse  of  hardening,  the  metal  flows, 
and  this  tension  is  relieved.  It  cannot  be  stated  definitely  whether  this 
hardness  is  produced  by  the  casting  or  by  the  cutting  process,  although 
the  remedy  seems  to  be  well  under  control.  The  effect  of  annealing 
is  to  remove  expansion  from  those  alloys  which  expand  only,  and  increase 
contraction  in  those  alloys  which  contract;  to  reduce  the  percentage  of 
mercury  required  to  amalgamate;  to  retard  the  setting;  to  facilitate 
amalgamation;  and  in  general  terms  annealing  may  be  said  to  increase 
both  crushing  stress  and  flow.  The  annealing  process  effects  a  reduction 
in  expansion,  an  increase  in  strength  and  flow,  reduces  the  percentage 
of  mercury  required  to  amalgamate,  and  facilitates  amalgamation  simul- 
taneously up  to  a  certain  point.     (See  page  291,  Test  6.) 

At  this  point,  which  is  different  for  different  alloys,  no  further  change 
is  produced  in  contraction  and  expansion,  but  all  the  other  changes 
continue  with  the  annealing.  The  alloy  continues  to  become  softer,  to 
require  less  mercury,  to  amalgamate  easier,  to  flow  a  little  more,  and, 
instead  of  continuing  to  increase  in  strength,  begins  to  decrease  in  strength. 

The  annealing  process  seems  to  have  a  zero  point  for  contraction  and 
expansion  where  no  further  change  is  produced  by  annealing,  but  not  so 
with  any  other  property.  There  is  a  changing  point  for  crushing  stress, 
where  the  alloy,  instead  of  increasing  with  annealing,  begins  to  decrease. 
This  can  be  readily  understood  when  it  is  considered  that  the  anneal- 
ing process  is  a  softening  process.  Freshly  cut  alloy  sets  so  rapidly 
because  of  its  denseness  and  affinity  for  mercury  that  thorough  amal- 
gamation is  impossible.  The  annealing  removes  this  property  of  setting 
so  rapidly,  and  gradually  admits  of  a  thorough  amalgamation;  but  if 
annealing  is  carried  too  far  the  alloy  becomes  too  soft  to  admit  of  the 
production  of  a  filling  of  maximum  strength.     No  one  thing  in  the  use 

'  Operative  Dentistry,  vol.  ii,  309.  ^  Dental  Cosmos,  vol.  li,  1909,  p.  7. 


272  VLASTliS 

of  alloys  seems  to  be  of  such  vital  iiiij)()rtance  to  the  profession  as  an 
understandintf  of  the  foregoiiit^  phenomena  reo;ar(linii;  annealin<,^ 

Oftentimes  alloys  are  pnrclutsed  in  (piantities  with  the  understanding 
that  they  have  been  aiiiirnlcd  and  that  no  fnrther  change  will  take  j)lace 
as  time  goes  on.  No  perceptible  change  will  take  j)lace  in  the  well-made 
alloys  in  contraction,  but  the  very  best  alloys  will  decrease  markedly 
in  strength,  set  nmch  slower,  require  less  mercury,  and  work  very  easily, 
within  a  year's  time  at  room  temperature. 

Strength  of  Alloys. — Strength  of  alloys  usually  indicates  those  prop- 
erties l)y  which  alloys  sustain  the  application  of  force  or  strain  without 
yielding  or  breaking,  and  may  be  considered  under  two  heads,  viz.,  crush- 
ing resistance  and  flow,  (rushing  resistance  is  that  property  by  virtue 
of  which  these  alloys  resist  force  without  fracturing,  while  flow  is  that 
property  by  virtue  of  which  they  resist  force  without  cIkiiu/c  in  shape. 

Crushing  resistance  of  these  alloys  may  be  treated  ( 1 )  as  a  pro[)erty 
of  the  alloys  used  to  form  amalgams,  and  (2)  as  a  pnjperty  of  the 
amalgam  mass.  The  crushing  resistance  of  these  alloys  before  they  are 
combined  with  mercury  is  much  higher  than  they  are  after  they  are 
cut  and  amalgamated,  mercury  increasing  the  plasticity  of  all  its  alloys. 
With  this  in  view,  it  is  obvious  that  within  certain  limits  any  alloy  un- 
combined  with  mercury  in  the  amalgam  will  increase  crnsning  resistance. 
The  crushing  resistance  of  these  alloys  from  which  amalgams  are  made 
is  controlled  by  the  composition  of  tiie  alloy,  the  amount  of  annealing, 
and  probably  (as  mentioned  before)  the  manner  of  casting  and  cooling. 
Silver  adds  to  this  property,  copper  does  likewise,  and  tin  detracts  from 
it  markedly.  Zinc  cannot  be  said  to  add  to  crushing  resistance,  it  being 
much  better  than  tin  in  this  respect  and  a  little  poorer  than  silver  and 
copper.  The  crushing  resistance  of  amalgam  prepared  from  these 
alloys  presents  not  only  the  same  phenomena  as  the  alloys,  but  the  addi- 
tional complications  arising  from  the  union  of  the  mercury  with  alloy. 

The  following  table  of  results  demonstrates  that  dental  amalgams 
have  no  definite  crushin<>-  resistance.' 


Alloy  No.  1.  Per  rent. 

Silver HS.OO 

Tin 20.50 

Copper 4,20 


Alloy  No   2.  Per  rent 

Silver f).5..")0 

Tin 25. 50 

(bpper 6.00 


Zinc 1.30       1      Zinc 3.00 

Crushing  resistance. 
Alloy  No.  2. 

4.52  pounds 

462      " 

453 

447 

447 

4,33 

367 

310 

163 

'  iSee  a  paper  by  the  writer  in  Dental  Pvcvicw,  April,  1907, 


Crushinc 

resistance 

Age  of  amalgam 

Alloy  No.  1. 

1  day 

435 

pounds 

2     " 

478 

4    " 

485 

24    " 

493 

42    " 

497 

85    " 

475 

205    " 

414 

341    " 

344 

491    " 

187 

NATlh'E  OF  AMALGAM  27;-| 

The  two  alloys  used  for  (liese  tests  were  selected  from  the  market  not 
simply  because  they  represented  some  of  the  l)est  products  (all  things 
considered),  but  because  they  represented  about  the  maximum  and 
mininumi  precenta^es  of  zinc  to  be  found  in  these  products  at  that  time. 
The  fillings  made  from  these  two  alloys  were  allowed  to  stand,  and  at 
different  intervals  six  fillings  were  crushed  at  a  time  and  an  average 
taken  as  the  crushing  resistance  of  the  alloy  at  that  time.  One  thing 
to  be  observed  is  the  increase  in  crushing  resistance  of  both  alloys  up  to  a 
certain  point,  after  which  there  was  a  decrease  in  crushing  resistance 
for  a  much  longer  time. 

Another  feature  of  interest  is  the  difference  in  time  required  for  each 
alloy  to  reach  its  maximum  crushing  resistance.  The  explanation  ottered 
for  the  variation  in  amount  of  crushing  resistance  was  briefly  this:  At 
the  time  of  making  the  fillings  they  were  composed  of  undissolved  par- 
ticles of  alloy  surrounded  more  or  less  completely  with  alloy  dissolved 
in  mercury,  forming  a  kind  of  cementing  substance.  From  this  time 
until  the  time  the  maximum  crushing  resistance  was  reached  the  cement- 
ing substance  was  passing  through  the  process  of  solidification.  , 

From  the  time  of  reaching  the  maximum  crushing  resistance  fprob- 
al)ly  from  time  of  amalgamation)  there  was  a  gradual  breaking  down, 
through  some  of  the  various  ways  previously  referred  to  under  nature  of 
dental  amalgam  alloys,  of  the  undissolved  particles  of  alloy.  As  an 
explanation  of  the  difference  in  time  required  for  the  maximum  crush- 
ing resistance  to  be  reached,  it  was  stated  that  it  was  due  to  the  ease 
with  which  the  alloy  amalgamates,  and  this  depends  obviously  upon  the 
composition  of  the  alloy.  In  this  case  the  alloy  containing  the  least 
silver  and  the  most  zinc  reached  its  maximum  crushing  resistance  first. 
P>om  the  nature  of  the  metals  this  should  be  expected.  Since  the  time  of 
these  tests  other  observations  have  been  made  which  not  only  confirm 
the  ones  already  mentioned,  but  appear  as  indisputable  proof  that  these 
alloys  are  changing  in  crushing  resistance  at  the  end  of  three  years. 

These  tests,  according  to  others  started  a  little  later,  appear  to  indicate 
these  changes  in  crushing  resistance,  although  they  were  not  carried  on 
long  enough  to  obtain  all  the  change.  Later  experiments  tend  to  show 
that  after  the  decline  in  crushing  resistance  at  about  the  end  of  one  and 
one-half  years  there  is  another  increase  for  a  year  or  more.  It  may  be 
said  that  a  cylinder  }  inch  by  g  inch  of  one  of  the  best  high  percentage 
silver  alloys,  properly  amalgamated,  will  resist  a  force  of  from  450  to 
500  pounds  after  it  has  stood  a  week  at  room  temperature.  A  cylinder  of 
the  same  dimensions,  under  the  same  conditions,  of  one  of  the  low  per- 
centage silver  alloys  will  resist  a  force  of  from  150  to  250  pounds.  These 
conditions  affecting  the  crushing  resistance  of  dental  amalgam  alloys 
may  be  modified  by  the  condition  of  the  cut  of  the  alloy,  the  manner  of 
incorporating  the  alloy  and  mercury,  the  amount  of  mercury  used  during 
amalgamation,  and  the  amount  of  mercury  left  in  the  filling. 
18 


274  PLASTICS 

A  comprehensive  consideration  ot"  the  actual  condition  of  theainal^^un 
mass  at  and  subsequent  to  insertion  reveals  that  these  hitherto  refifardcd 
as  primary  causes  of  a  modification  in  the  crushinii;  resistance  of  alloys 
are  in  reality  adjuncts  to  the  real  cause.  A  coarsely  cut  alloy,  for  examj)le, 
may  be  ground  in  a  mortar  with  sufficient  mercury  by  one  operator  until 
it  is  quite  fine,  while  it  may  be  hastily  mixed  with  too  little  mercury  and 
inserted  by  another.  The  interior  of  the  two  fillings  thus  made  cannot 
be  regarded  alike  either  from  a  chemical  or  physical  standpoint,  neither  can 
there  be  anything  but  a  great  diversity  of  changes  in  crushing  resistance 
expected  from  the  two  when  we  consider  carefully  the  thermochemical 
relations  of  mercury  with  the  constituents  of  the  alloys  used  to  form 
amalgams.  The  amount  of  mercury  left  in  the  filling  inffuences  crushing 
resistance  in  at  least  two  ways,  viz.,  by  its  mere  presence,  and  by  its 
action  with  the  undissolved  particles  of  alloy. 

If  mercury  be  present  in  too  large  (|uantities,  its  presence,  because  of 
its  liquid  state,  lessens  crushing  resistance  markedly.  On  the  other 
hand,  if  there  be  too  little  present,  the  crushing  resistance  will  be  lessened,, 
due  to  incomplete  amalgamation.  The  presence  or  al)sence  of  mercury 
obviously  facilitates  or  retards  the  breaking  down  of  the  undissolved 
particles  of  alloy. 

Flow  of  Amalgams. — A  solid  metal  can  flow  like  a  viscous  fluid  if 
sufficient  pressure  is  applied  (Hiorns).  The  property  seems  to  be  dif- 
ferent with  different  metals  and  varies  with  different  forms  of  the  same 
metal.  Some  metals  with  a  distinctly  granular  structure  seem  to  flow  less 
than  the  same  metal  when  in  a  less  granular  structure,  though  the  tenacity 
and  elongation  of  the  two  forms  may  be  nearly  identical.  The  differences 
in  the  rate  of  flow  l)etween  different  metals  depends  largely  upon  their 
plasticiit/,  by  virtue  of  which  they  yield  to  the  pressure  and  allow  the  mole- 
cules to  slip  over  each  other  and  assume  new  positions.  Dr.  Black  says:' 
''If  we  subject  pure  silver,  say  a  block  0.1  inch  s(|uare,  to  800  pounds  it 
will  yield  a  very  little  almost  as  soon  as  the  pressure  is  applied.  Then  it 
will  yield  no  more  until  the  weight  is  increased.  If  we  try  a  similar  block 
of  tin  in  the  same  way  we  find  it  softer.  It  will  yield  sharply  at  25  pounds, 
and  if  we  leave  it  under  this  pressure  without  increasing  it,  it  will  con- 
tinue to  yield  until  it  has  all  crawled  out  from  between  the  points  or  been 
reduced  to  a  thin  sheet.  Therefore,  the  tin  is  not  only  a  softer  metal,  but 
it  has  a  physical  property  totally  different  from  any  possessed  by  silver, 
the  property  of  continuous  flow  under  a  given  pressure."  This  indicates 
the  effect  of  tin  and  silver  upon  flow,  though  it  implies  that  the  flow  of 
tin  is  a  peculiar  property  rather  than  that  it  is  a  j>ro])erty  of  all  metals, 
tin  being  one  possessed  of  a  high  rate  of  flow. 

A  hard  metal  like  silver  has  an  ehtsiic  liinif,  which  must  be  exceeded 
and  the  pressure  maintained  in  excess  if  a  continuous  flow  is  produced, 
while  a  soft  metal  like  tin  has  practically  no  elasticity,  and  is  therefore 

*  Operative  Dentistry,  vol.  ii,  317. 


NATURE  OF  AMALGAM  275 

f'ap;il)Io  of  heiiio'  cliaii^vd  in  form  willi  almost  any  j)re.ssurc.  The  coin- 
position  of  the  alloy  controls  largely  the  property  of  flow,  the  hard  and 
elastic  metals  reducing  it  and  the  soft  ones  increasing  it.  The  efl'ect  of 
annealing  iijK)n  flow  depends  uj)on  the  composition,  some  formula?  being 
ali'ected  more  by  annealing  than  others,  (lenerally  speaking,  the  soften- 
ing of  an  alloy  by  annealing  increases  flow,  although  with  some  formulae 
flow  may  be  slightly  decreased  by  annealing. 

The  manner  of  incorporating  the  alloy  and  mercury,  percentage  of 
mercury  used  during  amalgamation,  the  condition  of  the  cut,  and  the 
amount  of  mercury  left  in  the  filling  each  modify  flow,  although  not  with 
regularity  even  in  a  given  alloy.  The  least  change  in  composition  so 
modifies  flow  that  each  of  these  phases  must  be  considered  separately 
with  each  formula.  An  excess  of  mercury  left  in  the  filling,  however, 
increases  flow  quite  regularly,  there  being  some  exceptions  in  the  ternary 
amalgams,  which  are  high  in  silver  and  low  in  tin.  The  property  of  flow 
depends  largely  upon  softness  and  absence  of  elasticity,  and  is  at  its 
maximum  in  alloys  known  as  low  silver  alloys. 

Fir,.  295  Fig.  296 


Spheroiding  of  amalgams  is  a  phenomenon  associated  with  flow  and 
increase  in  volume.  It  has  been  held  that  amalgams  possessed  a  strong 
tendency  to  become  spherical  in  shape,  due  to  the  influence  of  mercury, 
which  is  spherical  in  shape  when  divided  finely.  This  influence  which 
mercury  is  supposed  to  exert  seems  to  be  a  misconception  of  the  cause  of 
the  tendency  to  spheroid.  Mercury  is  spheroidal  or  globular  in  shape 
when  divided  somewhat,  the  smaller  the  particle  the  more  nearly  a  sphere. 
There  seems  to  have  been  a  tendency  to  regard  this  as  a  property  peculiar 
to  mercury.  This  is  not  true.  The  property  is  possessed  by  other  metals 
when  in  a  molten  condition. 

The  following  illustrations  show  a  spheroided  filling  produced  by  an 
alloy  which  increased  in  volume  and  flowed  easily.  It  was  composed  of 
silver.  49  per  cent.;  tin,  49.1  per  cent.;  and  zinc,  1.9  percent.  Fig.  295 
shows  the  surface  of  a  filling  made  from  this  "plastic"  alloy  and  kept  in 
the  thermostat  at  body  temperature  for  eight  months.  The  surface  is 
seen  to  be  spheroided.  Fig.  296  shows  a  companion  filling  like  that  of 
Fig.  295,  except  that  the  walls  of  the  test-tubes  are  highly  polished,  this 
being  accomplished  by  making  the  test-tube  with  removable  bottom, 


276 


I'/.ASTICS 


;is  seen  in  Fi<;.  2*.)7.  It  may  he  seen  that  (he  filhiii;  Fif^.  20(1,  iiiste;ul 
of  spheroidin^,  has  risen  nearly  as  much  at  tlie  horders  as  it  has  at 
the  centre  of  the  fiUin*,'.  The  filhnt,'  Fi^^  20.j  has  assumed  a  much  more 
spheroidal  surface  than  the  one  Fi<i;.  20(),  due  apparently  to  th<'  walls 
of  the  cavity  hein<;  purposely  roughened.  This  spheroidal  tendency 
seems  to  disappear  somewhat  with  alloys  high  in  silver  and  copper,  these 
allovs  possessing  less  flow.  It  has  not  heen  produced  to  any  extent  in 
allovs  which  do  not  expand  decidedly  and  flow  coinjjaratively  easily, 
although  irregidar  exj)ansions  and  contractions  appear  to  produce  in 
some  instances  liulged  surfaces  and  in  others  concave  surfaces  in  alloys 
possessing  little  flow  and  expansion.  The  consistency  of  the  mass  and 
density  obtained  in  working  and  packing  .seem  to  facilitate  irregular 
expansions  and  contractions.  Alkns  which  are  in  a  liquid  or  .semisolid 
condition  while  being  ])acke(l  will  show  a  tendency  to  .spheroid,  not 
because  of  expansion,  but  simply  becau-se  they  are  not  .solid.     Often- 


I'lG.  297 


times  the  packing  of  amalgam  results  in  the  profluction  of  layers  which 
have  the  mercury  well  pressed  out  and  others  which  have  large  exces.ses 
of  mercury,  and  during  the  .setting  process  the  mercury  becomes  equally 
distributed,  with  the  result  that  the  more  dense  layers  bulge,  while  tho.se 
which  are  less  dense  become  flattened  or  even  concave. 

Thermal  and  Chemical  Relations. — Amalgam,  like  gold  and  other 
metals,  is  a  conductor  of  thermal  impressions.  Just  where  amalgam 
stands  as  a  conductor  of  heat  and  electricity  is  not  known,  although 
it  can  safely  be  placed  quite  near  to  gold.  The  composition  of  the 
amalgam  will  influence  its  conductivity.  Any  ri.se  in  temperature 
will  usually  retard  and  a  fall  in  temperature  will  increa.se  conduc- 
tivity, although  the  resistance  of  alloys  to  conductivity  does  not  always 
behave  in  a  manner  that  would  be  expected  from  the  nature  of  their 
constituents.  Besides  being  .subject  to  change  in  volume  during  and 
subsequent  to  their  setting,  amalgams  expand  when  heated  and  con- 
tract on  cooling.  The  metals  of  which  these  amalgams  are  composed, 
within  certain  limits,  expand  or  contract  in  proportion  to  the  rise  or  fall 
in  temperature,  but  it  cannot  be  said  with  certainty  that  this  is  true  of 
these  amalgams.      Certain  anomalies  which  are  known  to  exist  make  it 


NATURE  OF  AMALGAM  277 

seem  possible  that  certain  temperatures  with  certain  formulae  might 
result  in  a  \ariation  from  the  general  rule.  Dental  amalgams  are  prac- 
tically insoluble  in  the  fluids  of  the  mouth.  The  connnon  solvent  found 
in  the  oral  cavity,  lactic  acid,  affects  them  but  little.  There  is,  however, 
a  constant  wasting  away  of  many  amalgams  due  to  the  formation  of  salts 
which  are  soluble  in  the  oral  fluids.  Amalgams  that  are  high  in  copper 
furnish  an  example  of  the  constant  wasting  which  may  be  due  to  the 
formation  of  the  green  basic  carbonate  in  small  quantities,  or  salts  from 
the  action  of  hydrogen  sulphid  and  soluble  sulphids.  The  two  principal 
classes  of  alloys  now  in  use  are  not  affected  this  way  to  any  appreciable 
extent. 

'i'here  are  probably  no  alloys  in  use  which  exert  any  particular  influ- 
ence upon  the  tooth  tissues  except  those  high  in  copper.  There  are  one 
or  two  alloys  heralded  as  great  tooth  preservers,  not  simply  because  they 
are  free  from  contraction,  expansion,  and  flow  after  insertion,  but  be- 
cause they  possess  "antiseptic  properties."  A  critical  examination  of 
them  fails  to  reveal  any  reason  why  they  should  exert  any  such  influence. 
The  action  of  copper  amalgam  upon  the  tooth  tissues  has  been  studied 
by  Miller,  Fletcher,  Witzel  and  others,  and  the  general  opinion  seems 
to  be  that  it  possesses  antiseptic  properties. 

Use  and  Manipulation  of  Amalgam. — The  advent  of  better 
methods  and  facilities  for  the  construction  of  inlays  and  crowns  each 
year  seems  to  reduce  greatly  the  amount  of  ainalgam  used.  It  can, 
however,  hardly  be  excluded  from  any  dental  practice  without  at  least 
an  occasional  injustice  being  done  the  patient  as  well  as  the  operator. 

As  a  general  rule,  amalgam  is  inserted  in  places  obscured  from  view 
and  places  difficult  of  access.  Among  the  former  may  be  mentioned 
cavities  on  the  lingual  surfaces  of  all  the  teeth,  distal  cavities  in 
cuspids,  bicuspids,  and  molars,  mesial  cavities  in  the  second  and  third 
molars,  buccal  cavities  in  the  second  and  third  molars,  and  cavities  on 
the  occlusal  surfaces  of  bicuspids  and  molars.  The  principal  cavities 
which  are  so  difficult  of  access  as  to  demand  amalgam  are  those 
situated  on  the  disto-buccal  and  distal  surfaces  of  the  second  molars 
and  all  cavities  in  the  third  molars.  Even  these  cavities  are  not 
always  difficult  to  fill  with  other  and  better  materials  than  amalgam. 
The  preparation  of  the  cavity  for  the  reception  of  amalgam  should  be 
done  with  as  much  care  as  for  the  reception  of  any  other  material. 
The  teeth  should  be  separated,  and  any  overhanging  gum  tissue  re- 
moved previous  to  the  preparation  of  the  cavity.  The  rubber  dam 
should  be  adjusted  whenever  possible,  so  that  disinfection  of  the  cavity 
may  be  accomplished  and  the  filling  inserted  in  the  absence  of  the  oral 
fluids. 

The  thing  of  greatest  importance  to  the  dentist  is  the  selection  of 
the  alloy.  Many  have  doubted  the  tooth-saving  qualities  of  the  high 
percentage  silver  alloys  designed  by  Black  over  those  of  Flagg  and  the 


278  PLASTICS 

older  workers.  Many  laud  the  low  pcrceiitai^'e  silver  allovs,  dcsiiriied 
not  by  Black,  but  by  the  students  of  his  work,  because  they  are  very 
li<,fht  in  color  and  work  easily,  while  others  adhere  to  copper  aiMal<i;ani. 
In  the  selection  of  an  alloy  from  which  to  make  amali^am  fillings 
it  must  be  remembered  that  the  qualities  most  desired  are  not  all  incor- 
porated in  any  one  kind  of  amal<(am.  Copper  amaln:am,  for  example, 
will  unquestionably  save  more  teeth  than  any  other  kind  because  it  is 
practically  free  from  change  in  volume  and  possesses  antiseptic  prop- 
erties; l)ut  it  turns  so  dark  in  the  mouth  and  causes  so  nuich  galvanic 
trouble  that  its  use  is  veiy  (juestionable.  Tiie  low  percentage  silver 
alloys  are  light  in  color  and  work  easily  because  they  contain  no  copper 
and  a  great  deal  of  tin;  but  they  flow  so  badly,  have  so  little  strength, 
and  change  so  much  in  volume  that  their  use  is  also  questionable. 
The  data  obtainable  show  that  the  alloys  known  as  high  percentage 
silver  alloys  made  by  relial)le  manufacturers  possess  the  greatest  num- 
ber of  desirable  qualities. 

It  is  very  important  that  an  alloy  made  by  a  competent  maker  be 
selected,  since  there  is  }n-ol)ably  no  product  in  dentistry,  and  it  is 
doubtful  if  there  ever  will  be,  that  is  subject  to  more  variations  and 
is  really  less  understood.  There  are  certain  principles  which  the  com- 
petent person  will  have  to  guide  lu'm,  and  certain  peculiarities  al)out 
these  bodies  which  a  few  have  discovered  and  mastered.  No  one 
desiring  to  serve  his  patient's  l)est  interest  will  make  his  own  alloy  with- 
out some  years  of  study  and  a  generous  investment  in  equipment.  He 
may  save  some  teeth,  in  fact  he  may  save  many,  but  such  alloys  cannot 
possess  uniformly  the  greatest  number  of  desirable  qualities.  The  high 
percentage  silver  alloys  are  made  by  some  manufacturers  in  two  and  three 
grades  as  regards  the  setting.  They  are  of  the  same  composition,  cut 
just  the  same,  and  marketed  just  the  same,  except  that  some  packages 
may  be  marked  "slow  setting,"  some  "ratlier  rapid  setting,"  and  others 
"rapid  setting."  The  difference  in  their  production  is  in  the  amount 
of  annealing  given  them,  annealing  causing  them  to  set  more  slowly, 
and  their  behavior  is  usually  more  marked. 

Alloys  marked  "  rapid  setting"  will  re(|uire  much  more  mercury  to 
amalgamate  them  if  they  have  not  been  in  stock  long  enough  to 
become  annealed.  They  will  set  so  rapidly  that  it  is  difficult  to  j)ack 
them  properly,  even  in  cavities  of  easy  access,  and  almost  impossible  to 
insert  them  where  there  is  not  ready  access.  The  amount  of  expansion 
that  will  take  })lace  sul)se(|uent  to  insertion  is  nuich  greater  with  im- 
properly annealed  alloys.  The  finished  product  is  represented  by  alloys 
marked  "slow  setting."  Some  manufacturers  make  their  high  per- 
centage silver  alloys  in  one  grade  only.  These  alloys  will  have  no  mark 
to  designate  their  manner  of  setting. 

The  alloy  to  be  selected  for  general  use  is  the  finished  product, 
although  the  occasional  use  of  "rapid  setting"  alloy  when  the  patient 


NATCRE  OF  AMALCAM  279 

cannot  I)c  soeii  liv  llu>  operator  to  (ini.sli  the  fillini;'  .seems  to  he  desii- 
al)le.  It  sliould  he  renicmhered  thai  while  alloys  marked  "rapid 
setting"  expand  more  than  those  marked  "slow  setting,"  contraction 
and  expansion  are  not  controlled  hy  the  manipulation  of  them  during 
amalgamation  and  insertion.  The  operator  may  modify  these  move- 
ments, hut  he  cannot  control  them,  the  controlling  factor  heing  com- 
position. 

In  choosing  an  alloy,  it  should  be  remembered  that  tlie  only  property 
which  can  be  controlled  by  the  operator  is  strength,  and  even  then  the 
alloy  must  be  properly  made  or  a  strong  filling  cannot  l)e  produced. 

A  strong  filling  cannot  be  made  from  a  poor  alloy,  although  a  weak 
filling  may  be  made  from  a  good  one.  The  amount  of  alloy  necessary 
for  the  filling  should  be  placed  in  a  small  ground  glass  or  Wedgwood 
mortar  and  groimd  with  the  required  amount  of  mercury  until  the  mass 
becomes  coherent  enough  to  be  turned  into  the  palm  of  the  hand  con- 
veniently, after  which  it  should  be  kneaded  rapidly  and  vigorously  for  from 
three  to  five  minutes,  depending  upon  the  coarseness  of  the  cut,  amount  of 
annealing,  and  composition  of  the  alloy. 

A  complete  union  of  the  alloy  and  mercury  cannot  be  effected  at 
ordinary  temperatures.  The  operator  must  be  guided  in  amalgamating 
these  alloys  by  the  consistency  of  the  mass.  It  should  be  fine  grained 
and  smooth,  and  tough  enough  to  be  rolled  out  into  a  long  roll  without 
breaking  before  the  mixing  is  discontinued. 

The  amount  of  mercury  to  be  used  with  a  given  w^eight  of  alloy  is 
slightly  more  than  the  weight  of  the  alloy.  The  proportions  given  by 
most  makers  of  high  percentage  silver  alloys  are,  approximately, 
alloy,  5  parts;  mercury,  7  parts,  by  weight.  These  proportions  are  as 
nearly  correct  as  can  be  determined  by  experiment,  although  7  parts  of 
mercury  will  be  found  none  too  much  for  alloys  marked  "rapid  setting." 
The  low  percentage  silver  alloys  of  all  grades  will  require  less  mercury. 
It  will  seldom  be  found  necessary  to  use  more  than  equal  weight  of  mer- 
cury for  a  given  weight  of  alloy,  to  make  a  smooth,  fine-grained  mass. 
The  amount  of  mercury  to  be  used  with  a  given  amount  of  alloy  of  known 
composition  is  a  cjuestion  which  cannot  be  answered  unless  the  "con- 
dition of  the  cut"  and  the  age  of  the  alloy  are  known. 

The  condition  of  the  cut  of  an  alloy  will  oftentimes  affect  the  rapidity 
with  which  the  alloy  becomes  annealed  in  the  warehouse  or  office. 

All  alloys  require  less  mercury  as  they  become  annealed,  hence  the 
proportions  given  by  makers  of  alloys  are  correct  for  a  comparatively 
freshly  made  alloy  only. 

The  older  any  alloy  becomes  the  easier  it  works,  the  weaker  it  is,  and 
the  less  mercury  it  requires,  although  if  properly  made  it  will  not  contract 
appreciably.  It  may  be  noted  that  manufacturers  having  similar  products 
recommend  slightly  different  amounts  of  mercury  to  be  used  with  a 
given  amount  of  alloy.    Some  products  may  be  marked:  " Use  5  parts  of 


260  PLASTICS 

alloy  with  7  parts  of  mercurv;"  "4  parts  of  allov  with  .')  jKirts  of  mercurv;" 
"9  parts  of  alloy  with  11  parts  of  mercury,"  etc.  Chemical  analyses 
show  many  of  these  alloys  to  be  nearly  identical  in  composition,  hut  there 
is  some  tlilierence  in  the  "cut"  of  them,  a  little  diil'crcncc  in  the  amount 
of  annealing,  and  probably  some  difference  in  the  manner  of  casting  and 
cooling,  which  accounts  for  the  variation  of  about  10  per  cent,  in  the 
amount  of  mercury  re(|uired.  The  correct  amount  of  mercury  to  be 
used  during  amalgamation  does  not  mean  the  amount  of  mercury  to  be 
left  in  the  filling.  It  means  that  a  slight  excess  of  mercury  should  always 
be  used  to  start  the  filling,  and  as  soon  as  it  is  noticed  it  should  be  re- 
moved. Dr.  Black  states'  that  "it  is  certainly  best  to  have  just  the  right 
amount,"  but  in  the  same  sentence  states  tiuit  "superfluous  merciny 
does  little  harm  if  removed  as  soon  as  noticed." 

Tin.  29S 

-.      -         ....    J 


Fletcher's  glass  mortar  and  ppstle. 

Dr.  Black  remains  practically  silent  on  the  subject  of  "permanency 
of  form"  or  changes  in  amalgam  subse(|uent  to  insertion.  Consistencv 
of  the  mass  seems  to  l)e  a  pronn'nent  factor  with  liim.  This  is  unques- 
tionably a  vital  point  in  the  packing  process,  but  an  amalgam  which 
packs  nicely  may  be  the  most  unstal)le  kind. 

Tiie  factor  of  supreme  importance  in  the  production  of  a  stable  amal- 
gam is  a  fairly  complete  solution  of  the  alloy  in  the  mercury.  Tin's  can 
07ily  be  produced  by  the  use  at  all  times  during  the  amalgamation  pro- 
cess of  slightly  more  mercury  than  makes  a  mass  of  the  consistency  to 
pack  well.  As  soon  as  the  mass  begins  to  stiffen  and  shows  a  tendency  to 
set,  any  surplus  mercury  should  be  removed.  There  is  not  even  a  remote 
possibility  of  an  operator  producing  a  true  amalgam  out  of  modern 
high  percentage  silver  alloys  under  ordinary  conditions.  The  best  that 
can  be  done  is  to  produce  as  much  true  amalgam  as  possible  around  the 

'  Operative  Dentistry,  vol.  ii,  :J22. 


NATURE  OF  AMALGAM  281 

undissolved  particles  of  alloy  and  yet  keep  the  mass  of  a  consistency  to 
pack  well,  "^riie  latter  often  depends  upon  the  presence  of  a  certain 
number  of  undissolved  alloy  particles. 

Alloys  low  in  silver  and  those  high  in  silver  that  are  very  old  may  dis- 
solve so  completely  in  mercury  that  the  mass  is  too  soft  to  pack  well.  A 
perfect  filling  cannot  be  made  with  them. 

The  ultimate  aim  of  the  operator  should  he  the  production  of  a  mass  of 
amalgam  that  is  both  stiff  and  tough  and  with  the  alloy  well  into  solution 
in  the  mercury.  To  accomplish  this  more  mercury  than  is  to  be  left  in 
the  filling:  should  be  used  to  start  amalgamation.  This  amount  is  stated 
on  the  packages  of  alloy,  and  is  correct  for  freshly  made  alloys.  Alloys 
one  year  old  or  more  do  not  require  as  much  mercury.  The  alloy  and 
mercury  may  be  weighed  on  a  balance  or  turned  out  approximately 
correct  by  an  experienced  operator  from  the  containers.  It  is  im- 
material whether  the  exact  amount  of  mercury  is  weighed  or  not,  as 
the  operator  never  knows  whether  these  proportions  are  correct.  It 
is  convenient,  however,  to  have  them  weighed  in  the  proportions  the 
maker  has  determined  for  fresh  alloys,  since  a  little  mercury  is  easily 
removed  during  the  amalgamation  process  if  it  be  found  necessary. 
Eai'lier  observations  of  the  writer  led  to  the  belief  that  alloy  and  mercury 
should  be  determined  and  weighed  carefully,  as  in  that  way  a  mass  was 
obtained  of  a  consistency  to  pack  well;  but  later  observations  on  the 
changes  occurring  in  these  bodies  subsecjuent  to  insertion  lead  to  the 
belief  that  w^iile  the  packing  of  an  alloy  is  a  vital  point  it  is  not  of  so 
much  importance  to  the  life  of  the  filling  as  to  have  the  alloy  worked 
with  sufficient  (though  not  enough  to  make  a  sloppy  mass)  mercury  at 
all  stages  up  to  the  packing. 

After  the  alloy  and  mercury  have  been  ground  in  a  mortar,  then 
turned  into  the  hand  and  worked  vigorously  for  a  few  seconds,  it  should 
be  noted  whether  the  mass  is  becoming  sloppy.  If  it  is,  a  little  mercury 
should  be  removed  quickly  between  the  thumb  and  forefinger.  The 
mass  should  not  be  put  into  pliers,  chamois  skin,  muslin,  or  anything 
else,  as  these  processes  require  too  much  time.  Sui-plus  mercury  should 
be  removed  quickly,  or  the  mass  stift'ens  so  that  the  object  of  the  opera- 
tion is  partially  or  wholly  defeated.  The  mass  should  be  quickly  turned 
into  the  hand  and  again  kneaded  vigorously.  If  it  again  appears  a  little 
sloppy,  remove  some  mercury  as  before.  Do  not  remove  too  much 
mercury,  or  the  alloy  wall  not  be  anywhere  near  completely  into  solution. 
Til  is  process  should  be  repeated  three  or  four  times,  the  last  time  using 
all  the  pressure  that  can  be  exerted  in  removing  the  excess  mercury,  so 
that  the  mass  will  be  stift'  enough  to  enable  it  to  be  packed  well.  A 
repetition  of  this  process  three  or  four  times  usually  consumes  from  three 
to  five  minutes  and  results  in  a  tough,  stiff,  and  fine-grained  mass. 

The  question  might  then  be  asked,  "What  is  an  excess  of  mercury?" 
And  it  might  be  answ^ered  in  a  general  way  by  saying  that  it  is  the 


2cS2 


J'LASTICS 


25 

35 

10 

30 

15 

35 

30 

lO 

35 

15 

7 

7 

7 

7 

7 

7 

12 

12 

12 

12 

12 

12 

2 

3 

4 

5 

6 

7 

Black's  set  of  amalgam  pluggers. 


(liiYerence  Ix-twccn  the  aiiiouiit  used  to  aiiial^aiiiatc   tlic  mass  and  (lie 
amount  that  should  \)v  left  in  the  lilhiin;. 

Aiiv  amount  of  nuTcurv  left  in  the  (iMin^f  over  and  al)ove  an  amount 
which  makes  a  .stifl",  touirli,  and  fine-grained  mass  of  amalgam  would, 

of  course,  he  regarded 
^^°-  ^^^  ass  u  p  e  r  H  n  o  n  s. 

Every     step     in    the 
amalgamation      j)r<)- 
cess  should   he  done 
rapidly,  not  allowing 
the   amalgam    to  lie 
still.     If  the  mass  lies 
still  a  few  seconds  it 
stiffens  so  muc-h  that 
the  particles  of  alloy 
are  not  broken  down 
in     tlie    mixing    and 
surj)lus    mercury    is 
usually    retained     in 
the  mass.    The  pack- 
ing should  he  begun  immediately,  using  flat-ended  serrated 
instruments.     Several  instruments  have  been  desiijned  for  the 
packing  operation,   but  the   consensus    of    opinion  seems  to 
favor  a  flat-ended  or  cup-shaped  serrated  instrument  such  as 
shr>wn  in  Figs.  299  and  300. 

The  round  burnisher  has  })een  used  with  some  degree  of 
success,  but  it  has  been  proved  that  it  does  not  give  the  maxi- 
mum density  or  adaptation.  Pluggers  used  for  foil  fillings 
have  been  used  somewhat  successfidly,  but  they  are  too  small 
for  most  places,  and  as  a  result  chop  the  amalgam  mass  to 
pieces  and  do  not  compress  it.  Great  care  should  be  exercised 
in  packing  amalgam,  as  it  is  a  most  difficnlt  material  to  adapt 
to  cavity  walls.  I'oo  little  pressure  results  in  a  weak  filling. 
Too  much  pressure,  such  as  that  exerted  by  sudden  blows 
from  a  mallet,  disturbs  the  whole  mass,  and  as  a  result  weakens 
the  filling.  Heavy,  steady  pressure  gives  the  strongest  and 
best  adapted  filling.  The  amalgam  mass  should  not  be  broken 
up  any  more  than  is  necessary  for  convenience  in  placing  it 
into  the  different  parts  of  the  cavity.  Much  has  been  said 
in  regard  to  the  part  of  the  cavity  in  which  to  begin  the  packing, 
but  it  is  doubtful  if  any  one  method  can  be  carried  out  in  all 
cavities. 

In  all  cases  an  effort  should  be  made  to  ?/W^e  the  amalgam, 
piece  after  piece,  between  the  opposing  walls  or  between  one  wall  and 
the  alreadv  condensed  amalgam,  finishing  bv  wedging  some  amal<;am 


NATURE  OF  AMALGAM  283 

between  the  main  mass  and  the  eavity  walls.  Experienee  will  teaeli  how 
much  force  ean  he  used  in  the  wed^ino-  and  what  size  of  plungers  will 
not  chop  the  mass  to  pieces.     Instruments  of  varying  sizes  nuist  Ije  in 


Fig.  300 


Ivory's  set  of  five  amalgam  carriers  and  pluggers. 


284  PLASTICS 

readiness  on  the  table,  so  that  the  operator  has  at  his  immediate  com- 
mand instruments  that  will  compress  and  wedge  amalgam  into  any 
pocket  or  crevice  that  may  appear  during  the  operation.  Amal- 
gam to  be  jjucked  properly  must  be  stiff.  Soft  amalgam  cannot 
be  packed  to  make  even  a  fair  margin  when  examined  under  the 
lens.  It  is  in  tliis  part  of  the  work  that  the  modern  high  percentage  silver 
alloys  exceed  all  others,  the  low  percentage  silver  alloys  with  no  copper 
scarcely  deserving  comparison.  The  cavity  must  have  four  walls  if  any 
degree  of  compression  is  obtained.  With  the  great  variety  of  matrices 
and  matrix  retainers  provided  by  the  manufacturers,  together  with  the 
facilities  at  the  operator's  command  for  making  special  matrices,  there  is 
seldom  occasion  for  inserting  an  amalgam  filling  without  the  cavity 
having  four  walls.     (See  Chapter  X  on  Matrices.) 

The  cavity  should  always  be  filled  to  overflowing.  Amalgam  should  be 
packed  with  force,  and  with  as  large  pluggers  as  are  consistent  witli  the 
operation,  upon  the  orifice  of  the  cavity  and  left  until  the  mass  has  become 
hard  before  any  of  it  is  removed.  After  the  mass  has  hardened  some- 
what, surplus  amalgam  should  be  removed  by  carving  toward  the  borders 
with  sharp  plastic  instruments  or  excavators,  so  that  amalgam  once 
packed  along  the  margin  and  allowed  to  stiffen  will  not  be  disturbed. 
Attention  may  l)e  directed  to  the  fact  that  this  can  only  be  accomplished 
with  the  high  percentage  silver  alloys.  They  excel  all  others  in  this 
feature  as  well  as  in  all  features  of  the  packing  process. 

Only  very  light  burnishing  should  be  done  at  the  time  of  insertion 
of  an  alloy,  lest  the  margins  be  disturbed.  The  matrix  should  be 
removed  with  great  care,  or  it  may  disturb  the  margins  or  even  the  bulk 
of  the  filling.  An  amalcram  fillinii'  should  be  finished  in  the  same  manner 
as  a  gold  filling  after  it  has  "fully  set,"  but  since  this  time  is  indefinite 
(see  section  on  Strength),  varying  with  different  alloys,  different  manipu- 
lation and  different  ages  of  the  same  alloy,  no  definite  time  can  be 
given  for  the  hnal  finish  of  the  filling. 

If  the  filling  is  given  its  final  finish  prior  to  its  reaching  its  maximum 
hardness  the  best  fiiush  cannot  be  ol)tained.  Generally  speaking,  forty- 
eight  hours  is  sufhcient  to  elapse  between  the  insertion  of  amalgam  Hlling 
and  the  time  of  giving  its  final  finish,  although  a  week  is  better. 

Amalgam  fillings  should  be  finished  repeatedly.  Xot  more  than  a 
year  should  elapse  after  the  insertion  of  an  amalgam  filling  before 
it  should  again  have  its  margin  polished  and  burnished. 

Attention  has  l)een  called  to  the  fact  that  alloys  have  bulk  changes  after 
as  well  as  at  the  time  of  insertion.  This  often  causes  the  filling  to  appear 
spheroided,  tilted,  warped,  or  otherwise  distorted  within  a  year  or  two 
after  insertion.  Such  fillings  sjiould  be  ground  tlown  with  small  stone.s 
and  the  surface  again  finished. 

Numerous  instruments  have  been  devised  for  carrying  amalgam  from 
the  table  to  the  cavitv,  and  for  finisliing  the  filling  after  it  has  stifi'euetl. 


N ATI' RE  OF  AMALGAM 


2S5 


Fip.  .'^01  sliows  an  iiistruiiuMit  with  a  spoon  at  each  end  which  may  he 
used  with  advantafjje  in  carrvin^r  amalgam  in  ahnost  all  cases.  Fig.  302 
shows  a  somewhat  diil'erent  device,  consisting  of  a  tube  into  which  is  fitted 


Fig.  301 


Fk;.  302 


Fig.  303 


i 


a  plunger,  both  of  which  are  on  a  regular  instrument  handle.  This 
instrument  is  useful  for  carrying  amalgam  to  remote  and  inaccessible 
cavities,  as  enough  compression  can  be  given  to  the  amalgam  by  the 


2S()  FLAiiTICS 

plunger  to  make  it  remain  in  (he  cavity,  a  feat  whicli  cannot  always  be 
accompli.slietl  with  the  sjjoon  instrument.  P'if^.  303  shows  an  instrument 
similar  in  j)rinciple,  designed  by  Dr.  II.  W.  Artluir.  It  is  (piite  as  useful  -ds 
the  one  shown  in  Fi<;-.  302  in  all  eases,  and  much  more  useful  in  many  cases. 
The  sleeve  and  plunf>er  are  constructed  on  a  curve.  They  are  long 
enouo'h  to  enable  the  operator  to  discharge  tiie  tube  with  considerable 
force  bv  means  of  pressure  on  the  finger  piece  located  on  the  plunger 
some  distance  from  the  end  of  the  instrument.  Fig.  300  shows  the  com- 
bination |)luggers  and  carriers  of  II.  W.  Ivory.  The  ends  of  the 
instruments  useil  for  canying  amalgam  are  cup-shaped  and  serrated, 
and  the  amalgam  is  carried  by  being  wedged  into  the  serrated  cups. 

During  the  packing  operation  mercury  is  often  removed  from  the 
amalgam  mass  and  icmains  upon  the  surface.  This  is  almost  always 
true  if  the  operator  uses  a  mallet  to  give  sharp  blows,  but  is  not  very 
marked  if  the  mass  has  been  worked  properly  and  the  excess  mercury 
removed  by  good,  firm  pressure  just  previous  to  packing,  when  the 
regular  amalgam  pluggers  are  used.  The  use  of  quick  blows,  as  has 
been  mentioned  before,  is  bad  practice,  since  it  disturbs  the  amalgam 
mass,  even  when  large  ])luggers  are  used,  and  usually  forces  too  much 
mercury  to  the  surface.  As  fast  as  mercury  appears  at  the  surface  dur- 
ing packing  it  should  be  removed  hastily  with  an  excavator  or  other 
instrument  and  more  amalgam  inserted  into  the  cavity. 

If  there  is  no  easy  access  to  the  cavity,  pressure  enough  to  bring  mer- 
cury to  the  surface  will  seldom  be  exerted.  This  is  also  the  case  if  the 
matrix  is  not  used.  It  is  quite  generally  true  that  if  a  litde  mercury  is  not 
removed  during  the  packing,  the  latter  has  been  faulty.  Gold  foil,  silver 
foil,  and  tin  foil  have  been  used  to  absorb  the  excess  of  mercury  appearing 
at  the  surface  of  amalgam  fillings,  and  little  harm  has  probably  resulted, 
although  this  practice  cannot  be  said  to  add  to  the  qualities  of  the  amal- 
gam. New  alloys  are  formed  upon  the  surface  when  any  one  of  these 
materials  is  used,  and  experiments  have  proved  that  mercury  and  one 
metal  do  not  form  an  alloy  having  the  most  desirable  qualities. 

When  tin  foil  is  used  to  absorb  mercury  appearing  at  die  surface  a 
soft  non-crystalline,  shrinking  alloy  results.  Similar  comment  may  be 
made  upon  the  use  of  the  other  materials,  gold  being  no  exception. 

Mercury  which  has  appeared  on  the  surface  during  the  packing, 
providing  the  packing  has  been  done  with  care,  should  be  removed  and 
not  used  again  without  being  redistilled.  The  affinity  of  such  mercury 
for  other  metals  is  probably  weaker,  even  though  it  remains  liquid. 

It  is  possible  that  the  presence  of  other  metals  in  mercury  may  be  found 
to  improve  its  different  qualities,  but  it  has  not  yet  been  done.  On  the 
other  hand,  mercury  which  has  been  removed  from  amalgam  during 
packing  has  almost  invariably  been  found*  to  contain  more  tin  than 

»  The  author. 


CO  I' r  Eli  AMALGAM  287 

other  constituents.  Dr.  IMaek's  later  observations  seem  to  confirm  this/ 
hut  in  the  same  chapter  he  states  that  "if  the  alloyiuf^  is  a  perfect  com- 
bination I  have  reason  to  beheve  that  no  one  metal  will  be  dissolved 
more  than  another."  It  is  a  fact,  however,  that  when  two  metals  are 
cooled,  certain  alloys  of  tiiese  metals  may  solidify  first  and  a  more  fusible 
alloy  of  these  metals  is  left,  and  is  known  as  the  eutectic  alloy  of  these 
metals.  It  is  a  general  rule  that  this  defect  is  intensified  when  four  or 
five  metals  are  used,  as  is  the  case  in  the  production  of  dental  amalfi;am 
alloys.  With  these  facts  in  view  we  may  assume  that  an  ingot  of  alloy 
before  it  is  cut  contains  quantities  of  globules  or  strata  of  eutectics  which 
may  be  more  soluble  as  well  as  more  fusible.  Mercury  which  has  had 
ever  so  slight  a  contact  with  alloy  should  be  discarded,  since  it  will  pick 
up  some  of  the  alloy  and  have  its  affinity  partially  satisfied. 

General  Considerations. — Washing  Amalgams. — Much  importance 
has  been  attached  to  the  washing  of  amalgam  just  prior  to  its  insertion 
or  during  the  mixing  process.  Such  substances  as  sodium  carbonate, 
dilute  acids,  ether,  chloroform,  and  alcohol  have  been  used,  but  with 
doubtful  value.  The  only  advantage  in  washing  amalgam  is  to  remove 
some  of  the  metallic  salts  which  form  upon  the  surfaces  of  the  particles 
of  cut  alloy.  It  has  been  stated  that  washing  increases  shrinkage 
(Flagg),  but  this  can  easily  be  accounted  for  when  it  is  considered  that 
alloys  free  from  shrinkage  have  been  made  only  since  Black's  work. 
Washing  amalgam  with  such  substances  as  chloroform  and  alcohol  will 
loosen  the  metallic  salts  sufficiently  to  permit  the  mercury  to  act  more 
energetically.  As  a  result,  the  filling  will  be  at  the  time  of  insertion  a 
little  lighter  in  color,  usually  a  little  stronger,  and  the  mass  will  set 
somewhat  faster.  Washing  usually  consumes  enough  time  to  allow  the 
mass  to  stiffen  somewhat,  and  in  this  case  it  is  a  decided  injury  to  the 
filling.  The  material  used  for  washing  generally  remains  to  a  consider- 
able extent  as  foreign  matter  in  the  filling.  This  in  no  case  improves 
the  integrity  of  the  filling,  and  in  some  cases  works  marked  injury. 

Empirical  Methods  of  Mixing  Alloy  and  Mercury. — Since  the  intro- 
duction of  amalgam  as  a  filling  material,  many  have  attributed  their 
success  with  amalgam  to  some  particular  method  of  incorporating  the 
alloy  and  mercury.  Some  have  used  the  mortar  alone,  others  the  hand 
alone,  and  still  others,  various  rubber  receptacles.  Many  dentists  seem 
to  have  lost  sight  of  the  fact  that  they  are  attempting  to  amalgamate  a 
hard  alloy.  As  soon  as  a  little  alloy  is  dissolved  the  mass  stifi'ens  some- 
what, and  if  the  amalgamation  is  not  carried  to  completion  quickly,  large 
particles  of  alloy  remain  undissolved.  This  is  particularly  true  when  the 
hand  alone  or  a  rubber  finger  cot  is  used.  Alloy  must  be  broken  down 
quickly  if  it  is  to  be  done  as  completely  as  possible.  It  has  been  sug- 
gested that  perspiration  from  the  hands  injures  the  amalgam.     This  is 

^  Operative  Dentistry,  vol.  ii,  318. 


288 


I'LASTICS 


true  only  to  the  extent  in  which  it  rf-mains  as  fon-i;,'n  niatMr  in  the  filling;, 
and  with  ordinary  precautions  this  injury  is  imperceptible.  A  small 
mortar  (see  V\^.  20S),  y)referahly  Wedgwood,  frjr  startini;  the  amali^a- 
mation  and  the  hand  for  its  cfjmj^letion,  seems  to  l)e  tlie  only  efjuipment 
used  by  those  wlio  are  studying  the  subject  carefully. 

Copper  Amalgam.  —Copper  amalgam  differs  .so  markedly  from  all 
other  amalgams,  br^th  in  fomj)osition  and  behavior,  that  it  deserves 
.separate  consideration.  '11k-  foregoing  data  apply  (;nly  in  slight  degree 
to  (•o[)f)er  amalgam.  It  is  an  alloy  of  copper  and  mercury,  and  may  be 
made  by  adfling  freshly  pn-fipitatffl  and  washed  mftallic  copper  to  an 
excess  of  mercury  until  (Im-  -olutifHi  i^  coniplftc;  the  excess  mercury  is 
dicn  removed  by  ecjinj^ressing  the  mass  in  ehamr^is  skin.  The  portion 
wlijfh  does  not  y>ass  through  the  ehamois  skin  is  [)aeked  into  nif^nlds  and 
all')ue(|  to  -tiireii,  Tlif  prodnei  (••;iii  be  piirehii^ed  in  the  form  of  small 
tablets,  whieli  may  be  softenet]  by  heating  gently  in  a  s})oon  f  I"'ig.  -iOl), 
after  wln'eh  it  may  be  moulded  and  packed  into  the  cavity.  .Many  den- 
tLsts  ha\e  made  copper  ;i  iii;ilg;ini  by  gri!i<hiig  copper  filings  in  a  moriar 
with  dilute  acids  and  wa.shing  with  a  variety  (jf  substance^  immediately 

Ik..  .'i04 


ilcatiiif;  hp'joii  for  copper  arnaJKam. 


before  irHcrlion  of  the  atnalgatn.  A  fur  better  inethofl,  and  one  which 
yields  a  product  r>f  greater  [>urify  and  uniforniity,  has  been  suggested 
by  Dr.  K.  r.  Kirk.  It  is  d(;ne  by  precipitating  the  copper  direr-tly  into 
the  mercury  by  electrolysis.  "Tin's  may  be  done  conveniently,"  says 
i)r.  Kirk,  "l)y  pouring  ;i  (|uaiititv  of  inerrnry  into  ;i  suitable  glass  vessel 
— a  small  battery  jar,  for  e.\ani[>k — and  susjjending  a  thick  plate  of 
cop[)er,  by  means  of  a  wooden  support,  some  distance  above  the  siu'face 
of  the  mercury. 

"Asatiirat<'ds(jlutionof  cupric  sulphate  is  then  poured  into  the  jar  until 
the  copper  plat<;  is  completely  submerged,  'i'he  cathode  pole  of  a  battery 
or  (jther  .source  (jf  electrical  current  is  then  connected  with  the  layer  of 
mercury,  and  the  anode  with  the  copper  plate.  All  of  the  cathode  elec- 
trode that  Is  in  cfjntact  with  the  cupric  sulphate  solution  should  be 
insulated  with  gutta-jjercha,  and  only  the  point  which  is  in  contact  with 
the  merciiry  left  exposed.  The  [>assage  o'i  the  current  causes  .solution 
fjf  the  copper  from  the  anode  and  deposits  it  in  the  mercury  contin- 
uously as  long  as  the  foregoing  conditions  are  maintained.  The  pre- 
cipitati«jn   should   be  continued   until   the  mercury  is  saturated,  which 


BUYING  AND  KEEl'lNG  ALLOYS  2S9 

will  !)('  ovidcMK'C'd   hy  (he  aj)|)e;ir;iiic('  of  t\\v  clKiriiclcri.stic  vrd  color  of 
tilt;  excess  of  co})per  tit  the  c-iithotle  pole. 

"  When  the  saturation  point  has  been  fully  reached  the  mass  should  he 
washed,  (irst  in  dilute  hydrochloric  acid  and  tluMi  in  water,  dried  and 
compressed,  as  is  usual  with  this  ainal<'iun  when  prej)arcd  hy  (he  oi'di- 
nary  process."  ('opper  amalgam  prepared  in  this  way  does  not  change 
in  volume  as  a  result  of  the  union  of  mercury  wi(h  the  co])per,  eidier  in 
the  nu'xing  or  sul)se(|uent  to  its  insertion  in(o  (Ik;  oral  cavity.  The  only 
alteration  in  form  that  oeeurs  is  the  comparatively  small  one  resuhing 
from  the  thermal  changes.  It  is  Hntise|)tie.  These  two  ((ualities  make 
one  of  the  best  tooth  preservers  now  in  use,  allhough  it  has  odier 
(jualities  so  undesirable  as  to  exclude  its  use  in  a  great  majority  of 
cases.  It  turns  almost  black  in  most  mouths,  has  a  [)eculiar  me(allie 
taste,  is  sometimes  a  marked  cause  of  voltaic  disturbance,  and  if  mois- 
ture through  any  cause  enters  between  it  and  the  walls  of  the  tooth  the 
latter  becom<\s  discolored.  Often,  although  no  visible  leakage  of  the 
filling  is  apparent,  there  is  discolored  tooth  tissue,  due  probably  to  the 
absorption  of  the  salts  of  copper  into  the  dentinal  tubules.  Coj)per 
amalgam  is  not  (|uite  as  indestructible  in  the  fluids  of  die  mouth  as  other 
amalgams,  as  it  readily  forms  salts  which  are  either  dissolved  or  carried 
away  by  abrasion.  This  is  commonly  shown  by  a  sort  of  cupping  out 
of  the  surface  of  the  filling. 

Classification  of  Amalgams. — Amalgams  may  ))e  divided  into  classes 
according  to  the  number  of  constituent  metals.  A  binary  dental 
amalgam  may  be  re|)resented  by  copper  and  mercury  or  palladium  and 
mercury,  each  of  which  has  a  very  limited  usefulness  in  dentistry.  Some 
of  the  older  alloys  of  silver,  tin,  and  mercury,  such  as  that  designed  by 
Dr.  Townsend,  represent  what  may  be  called  a  ternary  dental  amalgam. 
Amalgams  of  silver,  tin,  copj)er,  and  mercury,  such  as  designed  by  Dr. 
Flagg,  may  l)e  said  to  be  (jiuiternary  tlental  amalgams.  This  class  is 
also  represented  by  the  so-called  plastic  amalgarns  made  since  18U5-l(Si)(), 
and  composed  of  silver,  tin,  zinc,  and  mercury.  The  high  percentage 
silver  amalgams,  composed  of  silver,  tin,  co})per,  zinc,  and  mei'cury, 
may  well  represent  a  quinary  amalgam.  The  terms  binary,  ternary,  etc., 
have  not  gained  in  popularity  with  the  profession  in  the  last  decade, 
although  amalgams  are  in  use  representing  each  of  the  classes  mentioned. 

Buying  and  Keeping  Alloys. — The  question,  "Which  is  the  best  alloy 
to  buy?"  is  asked  so  often  that  it  seems  quite  certain  diat  the  pro- 
fession in  this  particular  does  not  exercise  the  same  judgment  with 
which  it  selects  other  dental  materials.  It  indicates  (|uite  clearly  that 
there  is  yet  much  mystery  surrounding  the  purchase  of  an  alloy.  When 
supplies  the  nature  of  which  is  not  understood  are  re(|uired,  the 
majority  of  the  profession  select  them  from  a  dealer  who  is  Ix^lieved  to 
be  reliable  in  this  respect  and  who  is  known  to  be  wholly  reliable  in 
others.  As  a  rule,  the  larger  supply  houses  are  best  e(jin'pped  for 
19 


290  PLASTICS 

tlistrihutinf)-  uniform  supplies  of  all  kinds,  and  most  likely  to  secure  the 
services  of  competent  men  to  manufacture  (heir  })roducts.  This  is  true 
in  the  manufacture  of  alloys,  and  should  he  used  as  a  ^niide  in  their 
selection.  Sometimes  a  good  product  comes  from  a  dealer  who  is  not 
well  or  favorably  known,  but  this  is  the  exception  rather  than  the  rule. 
Alloys  and  cements  above  all  other  products  should  be  made  and  j)laced 
upon  the  market  by  competent  chemists  if  the  dentist  is  to  be  rewarded 
for  his  energies.  The  practising  dentist  should  never  attempt  the  manu- 
facture of  these  products  himself  without  first  spending  considerable 
time  preparing  himself  by  learning  the  peculiarities  of  these  products 
with  special  apparatus  built  for  the  purpose. 

Dentists,  as  a  rule,  are  kept  changing  alloys  by  solicitous  dealers 
who  advance  this  or  that  quality  of  their  alloy  as  a  cure-all.  P'or 
example,  one  dealer  lauds  his  product  as  being  superior  because  it 
contains  more  silver  than  a  like  article  made  by  another.  Another 
makes  the  same  claims  regarding  the  quantity  of  zinc  in  his  product. 
Others  advance  the  argument  that  the  manner  of  cut  of  their  manu- 
facture has  much  to  do  with  the  success  attending  its  use,  and  so  it  is 
with  nearly  every  dealer.  These  arguments  generally  reward  the  dealer 
with  sales  because  dentists,  as  a  rule,  are  not  sufficiently  informed  on  the 
subject  to  enable  them  to  judge  the  merits  of  the  products  themselves. 

It  is  true  that  some  of  the  best  manufacturers  differ  as  to  what  con- 
stitutes the  "best  alloy  all  things  considered,"  but,  as  a  rule,  the 
difference  of  opinion  is  an  honest  one  rather  than  an  effort  on  the  part 
of  the  producer  to  lessen  the  first  cost  of  the  article.  This  is  shown  by 
several  leading  dealers'  products,  which  are  found  to  contain  from  65 
per  cent,  of  silver  to  68  per  cent,  of  silver,  yet  each  will  claim  to  have 
an  alloy  made  after  Dr.  Black's  plans,  etc.  The  maker  who  uses  68  per 
cent,  of  silver  knows  that  he  obtains  a  little  stronger  filling,  although 
he  is  conscious  of  the  fact  that  it  works  a  little  harder  and  sets  faster 
than  one  that  contains  only  65  per  cent,  of  silver.  On  the  other  hand,  he 
who  uses  65  per  cent,  of  silver  knows  that  his  product  works  a  little 
easier  and  sets  a  little  slower,  although  he  is  conscious  that  it  is  a  little 
weaker.  The  maker  who  uses  only  65  per  cent,  of  silver  probably  con- 
siders it  better  to  give  the  operator  a  little  more  time  to  work  than  to 
have  a  little  stronger  filling. 

The  same  is  true  of  the  quantity  of  zinc  now  used  in  high  percentage 
silver  alloys.  Some  claim  better  and  permanent  light  color  in  the 
mouth  as  a  result  of  the  use  of  a  little  more  zinc,  while  others  admit  a 
loss  in  color  as  a  result  of  its  elimination,  but  claim  to  have  a  product 
more  permanent  in  form.  Neither  disputes  the  other's  claims,  but  each 
places  greater  stress  upon  the  distinctive  qualities  of  his  product  in 
contrast  to  those  of  his  competitors.  Thus  it  becomes  a  matter  of 
judgment  which  quality  is  of  most  importance. 

The  leading  dealers'  high  percentage  silver  alloys  are  all  good,  well- 


BUYING  AND  KEEPING  ALLOYS  291 

iTiiulo,  luiiforin  products,  uud  excej)!  for  tlie  diiferenccs  mentioned,  tliey 
are  nearly  of  e(jiial  value  from  a  practical  standpoint.  Whether  an 
alloy  contains  (if)  or  (iS  per  cent,  of  silver  is  not  a  <j;nide  to  the  (|uality 
of  either.  The  same  is  oenerally  true  with  the  small  (juantities  of  zinc; 
now  used,  although  it  is  ([uite  generally  understood  that  zinc,  while  it 
improves  color,  facilitates  change  in  volume  subsequent  to  insertion 
when  used  in  an//  (piantity.  Dentists  eamiot  rely  upon  the  (juantity  of 
i((('h  or  anij  constituent  as  a  guide  to  ((uality,  although  present  knowl- 
edge of  the  subject  confines  the  quahties  of  each  constituent  for  the 
best  alloys  to  the  ranges  stated  on  page  265.  All  things  considered, 
the  high  percentage  silver  alloys  are  best,  and  should  be  chosen  by 
dentists. 

There  are  perhaps  some  places  where  the  quick-setting  properties 
make  the  use  of  these  alloys  questionable,  but  taken  as  a  general  rule, 
dentists  soon  learn  to  open  up  the  orifice  of  the  cavities  and  master  the 
manipulation  of  these  quick-setting,  stiff-working  products.  When  pur- 
chasing an  alloy  from  a  manufacturer  who  makes  his  product  in  both 
filings  and  shavings,  the  filings  should  be  chosen.  Shavings,  as  a  rule, 
are  not  of  the  proper  shape  to  permit  their  being  dissolved  readily  in 
mercury.  Not  all  manufacturers  make  their  products  "cut  in  two 
forms."  As  some  dentists  demand  them,  the  maker  sometimes  can 
hold  his  trade  by  no  other  means  than  by  supplying  shavings  to  those 
who  want  them. 

Some  makers  of  high  percentage  silver  alloys  make  only  one  grade  of 
alloys  as  regards  setting  qualities,  while  others  make  their  product  in 
two  or  three  grades.  This,  too,  is  usually  done  to  catch  trade,  since  most 
makers  are  aware  that  if  more  than  one  grade  is  supplied,  some  of  the 
grades  are  imperfect  products  at  the  time  of  making.  "Rapid  setting," 
"slower  setting,"  and  "slow  setting"  are  terms  used  to  designate  these 
products.  They  are  the  same  in  composition,  but  have  not  had  the 
same  amount  of  annealing.  The  accompanying  chart  shows  the  action 
of  one  of  these  alloys  in  the  hands  of  the  writer. 

Formula— Ag  68,  Sn  26.50,  Cu  4.20,  Zn  1.30  =  100. 


Test 

Time  of 

annealing 

Percentage  of 

Points  of 

number. 

at  49°  C. 

mercury. 

expansion. 

Manner  of  setting. 

1 

0 

63.00 

19 

Extremely  rapid 

2 

1 

day 

59.00 

7 

Slower 

3 

-  2 

days 

58.00 

3* 

u 

4 

3 

"" 

57.40 

n 

" 

5 

5 

" 

57.25 

f 

" 

6 

7 

" 

57.00 

h 

tl 

7 

10 

It 

56.60 

i 

" 

S 

15 

" 

56.10 

h 

" 

9 

20 

" 

55.50 

i 

" 

10 

25 

" 

54.80 

i 

" 

Tests  Nos.  4  and  5  indicate  about  the  manner  of  setting  that  most 
completed  products  would  possess  and  would  be  marked  by  the  maker  as 


292  PLASTICS 

"slow  setting."  Tests  Xos.  2  and  o  indicate  approximately  tlic  man- 
ner of  setting  that  the  j)roducts  of  some  makers  would  possess  and 
would  be  marked  "  rapid  setting,"  "slower  setting,"  etc.  These  products 
are  hut  partially  annealed,  and  may  be  regarded  as  incomplete.  If  the 
product  of  a  manufacturer  who  makes  several  grades  is  to  be  used,  the 
one  marked  "slow  setting"  should  be  chosen  for  immediate  use.  If  the 
alloy  is  purchased  in  (juantities,  it  is  often  advisable  to  select  the  "slow 
setting"  for  immediate  use  and  some  of  the  other  grades  for  future  use, 
because  the  "rapid-setting"  alloys  become  "slow  setting"  by  standing 
at  (jrdinary  temperatures. 

Unfortunately,  the  date  of  manufacture  of  alloys  is  not  stamped  upon 
the  package.  This  should  be  done,  as  the  dentist  has  no  protection 
against  the  purchase  of  old  alloys  which  are  unfit  for  use,  other  than 
the  seller's  honesty.  As  a  rule,  alloys  which  have  stood  in  the  market 
six  months  have  deteriorated  somewhat,  and  in  a  year  they  are  not 
good  for  general  use.  Dentists  should  select  their  alloys  with  this  in 
view.  Buying  in  larr/e  quantities  is  not  always  safe,  even  if  care  has 
been  exercised  in  selecting  the  product.  Alloys  should  not  be  kept  near 
a  heater,  in  the  sun  during  the  summer  months,  or  in  an  overheated 
room  for  any  length  of  time.  Alloy  for  immediate  use  must  be  at  hand, 
but  the  remainder  should  be  kept  in  a  cool,  dry  place.  Otherwise  even 
a  comparatively  small  stock  of  alloy  will  become  so  much  annealed  in  a 
short  time  that  it  should  not  be  used. 

Discoloration  of  the  Tooth  Tissue. — This  seems  to  occur  much  more 
rapidly  with  some  amalgams  than  with  others.  It  has  been  ol)served 
that  the  high  percentage  silver  alloys  and  the  so-called  plastic  alloys 
make  amalgams  which  do  not  perceptibly  discolor  the  tooth  tissues  if  they 
are  properly  manipulated.  Both  of  these  classes  of  alloys  remain  cjuite 
light  in  color  in  almost  all  mouths,  although  the  "plastic  amalgams"  are 
the  lighter  of  the  two.  From  this  it  would  seem  that  the  composition  of 
the  alloy  from  which  the  amalgam  was  made  controlled  the  amount  of 
discoloration  which  took  place  on  an  amalgam  filling.  Dr.  Black  and 
Dr.  Adolph  Witzel  attribute  the  lack  of  discoloration  of  tooth  tissue  by 
some  amalgams  to  the  fact  that  the  filling  was  imperfectly  adapted  or  had 
decreased  in  volume,  thus  allowing  moisture  to  penetrate  between  the 
walls  of  the  tooth  and  filling.  This  is  probably  an  important  factor  in 
this  connection,  but  the  composition  of  the  alloy  seems  a  greater  one. 
Examination  by  the  writer  of  a  large  number  of  mouths  containing 
fillings  made  of  alloys  composed  of  approximately  49  per  cent,  of  silver, 
49  per  cent,  of  tin,  and  2  percent,  of  zinc  failed  to  reveal  any  evidence 
of  discolored  tooth  tissue,  and  only  very  few  fillings  that  were  even 
darkened.  A  similar  examination  of  a  large  number  of  fillings  made 
from  alloys  composed  c^f  approximately  08  per  cent,  of  silver,  26.5  per 
cent,  of  tin,  4.2  per  cent  of  copper,  and  1.3  per  cent,  of  zinc  that  showed 
a  majority  was  discolored  somewhat,  but  no  evidence  of    discolored 


DISCOLORATION  OF  THE  TOOTH  TISSUE  293 

tooth  tissue  was  found.  Of  course,  an  examination  of  this  kind  does 
not  reveal  the  condition  of  the  surface  of  the  hlhn^-  next  to  tlie  tooth, 
except  at  the  margins.  It  does,  however,  show  tlie  tendency  of  these 
alloys  to  discolor  when  exposed  to  the  action  of  the  saliva.  Both  of  these 
alloys,  it  will  he  noted,  contained  zinc,  and  tiie  lighter  of  the  two  con- 
tained no  copper.  Products  similar  to  Flagg's  GO  percent,  silver,  35  per 
cent,  tin,  and  5  per  cent,  copper  alloy  have  been  known  to  discolor 
quite  markedly  in  most  mouths,  and  have  been  the  cause  of  much 
discolored  tooth  tissue.  Since  no  such  combination  known  is  free  from 
shrinkage,  it  is  impossible  to  say  whether  such  discolored  tooth  tissue  was 
caused  l)y  the  slirinkage  or  the  character  of  the  amalgam,  or  both.  It  is 
probable  that  amalgams  similar  to  that  of  Dr.  Flagg's,  which  do  not 
contain  zinc,  will  cause  discolored  tooth  tissue  if  used  at  a  stage  where 
shrinkage  is  taking  place  or  if  they  are  imperfectly  adapted. 

Much  has  been  claimed  for  the  presence  of  zinc  in  even  small  quan- 
tities in  alloys  used  for  dental  amalgams.  Just  how  the  profession  will 
consider  it  in  the  future  cannot  be  definitely  stated,  since  most  of  the 
writings  on  the  subject  agree  that  it  is  the  constituent  which  facilitates 
change  in  volume  subsequent  to  insertion.  The  same  writers  agree, 
however,  that  it  prevents  discoloration  of  the  amalgam  as  well  as  of  the 
adjacent  tooth  tissue. 

Elimination  of  zinc  from  high  percentage  alloys  would  leave  a  product 
composed  of  silver,  tin,  and  copper,  the  same  as  Dr.  Flagg's,  although 
the  percentages  would  be  slightly  changed.  Dr.  Black  states*  that  "0.5 
per  cent,  of  zinc  is  inadmissible  for  the  reason  that  the  amalgam  will 
continue  to  change  bulk  very  slowly  for  five  years  or  longer."  If  his 
latest  judgment  in  this  respect  were  to  be  carried  out  by  the  makers 
of  these  products,  there  would  not  be  much  difference  in  color  between 
alloys  made  after  his  plans  and  those  of  Dr.  Flagg,  although  they  would 
proljably  have  the  advantage  of  being  free  from  shrinkage. 

It  is  probable  that  the  makers  of  amalgams  will  endeavor  to  incor- 
porate the  zinc  in  such  a  manner  as  to  keep  the  amalgams  from  moving 
after  insertion,  rather  than  permit  a  reduction  in  color  and  a  step  back- 
ward. Plans  have  already  been  advanced  by  one  or  two  makers  of 
alloys  whereby  the  zinc  is  incorporated  into  the  amalgam  almost  inde- 
pendently of  the  other  constituents.  Dr.  Black  states  that  this  action  of 
zinc  in  the  change  in  bulk  was  so  subtle  that  it  was  not  at  first  dis- 
covered, and  suggests  its  elimination  from  these  products.  It  is  doubt- 
ful whether  the  profession  will  agree  to  return  to  amalgams  of  a  darker 
color,  even  if  there  is  some  change  in  bulk.  With  the  promise  of  new 
methods  of  incorporating  zinc  and  other  products  it  is  questionable 
whether  this  will  be  necessary. 

Alloys  which  have  not  been  cut  too  coarse,  and  have  been  worked 

^  Operative  Dentistry,  vol.  ii,  312. 


294 


PLASTICS 


thoroughly  by  the  dentist  to  a  rehuively  eomplete  sohition  of  the  alloy  in 
the  mercury,  have  lon^  f>;iven  enough  service  to  warrant  their  conlinued 
use.  The  dentist  can  prevent  much  of  tlie  change  in  hulk  hy  his  selec- 
tion of  alloy  and  mani{)ulation  of  it. 

Some  claim  that  amalgams  may  discolor  the  dentin  by  a  percolation 
into  the  dentinal  tubules  of  salts  formed  when  amalgam  was  placed 
in  contact  with  tlie  open  ends  of  these  tubides,  the  filling  remaining 
water  tight.  The  writer  iuis  had  his  attention  called  t(j  this  by  two  or 
three  practitioners  who  are  using  copper  amalgam  in  an  occasional 
remote  cavity.     Amalgam   which   has  discolored   usually   takes  on  a 

Fig  g05 


Black's  micrometer. 


blackish  hue.  Tooth  tissue,  on  the  other  hand,  may  appear  brown,  ])lack, 
or  green,  the  latter  being  the  case  when  a  silver-tin  alloy  containing  a 
large  percentage  of  copper  is  used.  The  extent  of  the  discoloration  of 
tooth  tissue  depends,  apart  from  the  composition  of  the  alloy,  largely 
upon  the  access  of  the  saliva  to  the  surface  of  the  filling  next  to  the  cavity 
walls  and  upon  the  size  of  the  dentinal  tubules.  If  the  tubules  are 
quite  small  or  are  obliterated,  there  will  not  be  an  extensive  discoloration. 
If  the  amalgam  is  one  which  discolors  readily  and  there  is  opportunity  for 
the  saliva  to  penetrate  between  the  cavity  wall  and  the  filling,  rapid  and 
extensive  discoloration  will  occur  if  the  dentin  is  capable  of  being  pene- 


MEASURING  CONTRACTION  AND  EXPANSION 


295 


trated.     On  the  other  hand,  if  there  is  very  Httle  aceess  for  the  saliva 
the  discoloration  will  he  slow  and  less  extensive. 


Fic;.  306 


A  A  represent  two  jewelled  bearings  from  which  swing  the  two  levers  D  D.  These  two  levers 
are  counterbalanced  by  the  two  adjustable  counterweights  B  B,  which  enable  one  to  bring  the 
instrument  into  contact  with  the  filling  at  E  with  a  minimum  amount  of  pressure  upon  the 
filling.  As  these  levers  are  small  steel  needles,  this  amount  is  very  small  when  the  counter- 
weights are  adjusted,  and  at  the  same  time  allows  one  to  use  very  long  levers,  which  is  a 
decided  advantage.  C  represents  a  small  mirror  in  front  of  which  swings  the  longer  lever  D, 
which  must  coincide  with  the  fine  line  across  the  mirror  every  time  a  reading  is  taken  at  the 
vertical  bar  F.  This  vertical  bar  is  ground  to  a  knife-edge,  so  that  it  easily  falls  upon  or 
between  the  graduations  on  the  disk  G.  The  bar  also  contains  graduations  which  are  the  same 
distance  apart  as  the  threads  on  the  micrometer  screw  H,  thus  enabling  one  to  tell  at  a  glance 
how  many  turns  the  screw  has  mads. 


Measuring  Contraction  and  Expansion. — Doubt  has  been  expressed  in 
regard  to  the  accuracy  of  a  micrometer  for  determining  contraction  and 


290 


PLASTICS 


expansion.  Those  who  liave  had  experienee  in  (leteriniiiiii^-  densities  hy 
the  speeifie  gravity  method  are  usnally  skej)tieal  about  the  aeenraey  of 
the  tests  for  the  alloys  if  the  maker  has  u.sed  a  micrometer.  The 
micrometer,  however,  has  gained  in  popularity  since  alloys  have  been 
made  which  have  practically  only  one  movement,  viz.,  expansion.  The 
Wedelstaedt  steel  test-tube,  as  modified  by  the  writer,  shown  in  Fig.  297 
has  gained  in  popularity  sinuiltaneously  with  the  micrometer  as  a 
receptacle  for  making  test  fillings.  These  receptacles  are  used  in  con- 
nection with  micrometers  of  various  designs.  Fig.  305  shows  the  one 
designed  by  Dr.  Black,  Figs.  3()()  and  Ii07  show  the  one  designed  by  the 
writer.  A  casual  observation  will  show  that  these  instruments  measure 
the  upward  flow  of  metal  caused  by  an  amalgam  which  ex])ands,  but  this 
is  not  the  case  when  the  amalgam  contracts,  as  contraction  tends  to 
take  place  in  the  manner  shown  in  Fig.  308.  The  micrometer,  a  much 
more  convenient  means  of  determining  expansion  than  the  s])ecific 
gravity  method,  is  usually  employed  for  this  purpose,  although  it  is  con- 
sidered of  little  value  in  determining  contraction.     Wliile  the  specific 


Fig.  308 

l~  — 

-T 

1 

1 

Diaieram  of  aniiilgani  slinukage. 


gravity  method  is  considered  the  most  accurate  means  of  determining 
both  contraction  and  expansion,  its  results  do  not  always  coincide  with 
those  taken  on  a  micrometer  for  expansion.  An  amalgam  whic-h  shows 
an  expansion  on  the  micrometer  may  show  a  contraction  when  tested  by 
the  specific  gravity  method.  This  is  usually  the  case  when  alloys  are 
coarsely  cut  and  are  not  well  broken  down  in  the  mercury  during 
amalgamation.  Such  an  amalgam  filling  which  is  smooth  at  the  time  of 
making  becomes  somewhat  porous  within  a  few  hours,  owing  to  the 
absorption  of  mercury  from  the  interstices  on  the  surface  to  the  interior 
of  the  filling.  The  specific  gravity  method  will  measure  these  inter- 
stices and  show  a  contraction,  while  the  micrometer  giving  only  a  linear 
measurement  may  show  that  the  linear  dimensions  have  actually 
increased. 

CEMENTS 

The  cements  obtainable  for  dental  purposes  consist  chiefly  of  the 
zinc  oxychlorids  and  three  classes  of  oxyphosphates.  The  oxysulphate 
has  been  used  some  in  the  past,  but  hardly  deserves  consideration  any 


CEMENTS  297 

lon<:jer.  The  oxyclilorid  is  formed  by  tlie  foinhination  of  lii<i;lily  cal- 
cined oxid  of  zinc  and  zinc  chlorid.  The  oxyj>lio.sj)hate.s  are  formed  by 
tlie  combination  of  a  more  or  less  modified  phosphoric  acid  with  one  or 
mon*  oxids  of  metals. 

Zinc  c'hluiiil  +  .         Oxid  of  zinc  =  Oxychlorids. 

Oxid  of  zinc  ^  Basic  zinc  phosphates  \  Not^-alkaline 
Oxid  of   copper    -  Oxyphosphate  of  copper. 


Phosphoric  acitl     + 


IUerylliuni. 
Silicia       Silicate  cements. 
Ahiininum. 
Calcium. 


The  foregoing  diagram  of  the  different  cements  sliows  at  a  glance 
the  classification  of  the  substances  which  form  these  compounds.  For 
example,  the  first  compound  is  composed  of  zinc  chlorid  and  an  oxid 
of  a  metal. 

The  three  classes  of  oxyphosphates  are  composed  of  oxids  of  metals 
with  phosphoric  acid.  The  zinc  oxychlorids  have  been  used  for  a 
variety  of  purposes,  but  have  been  almost  displaced  by  newer  com- 
pounds known  as  improved  oxyphosphates.  When  calcined  zinc  oxid 
is  combined  with  zinc  chlorid,  a  very  white  basic  zinc  salt  is  formed 
which  sets  quite  promptly,  although  its  physical  properties  which,  meet 
the  requirements  of  dentistry  are  few  in  number. 

Recent  improvements  in  the  three  classes  of  oxyphosphates  have 
placed  them  where  they  meet  many  of  the  long  sought  for  cjualities  of 
this  material.  These  compounds  resemble  amalgams  in  that  the  powder 
portion  is  usually  in  excess  in  the  mass  after  it  has  set.  Dr.  Ames  has 
"somewhat  figuratively"  applied  the  term  "basic"  to  these  compounds, 
although  it  is  hardly  in  keeping  with  chemical  nomenclature. 

\Vlien  calcined  zinc  oxid  is  brought  into  contact  with  phosphoric 
acid  a  part  of  the  oxid  goes  into  solution,  but  as  a  putty-like  consistency 
is  approached,  the  mass  consists  of  many  times  one  equivalent  of  the 
base  for  each  one  of  the  acid.  The  oxyphosphates  (also  the  oxychlorids) 
assume  the  aspect  of  concrete  at  the  time  of  setting  by  containing  a 
cementing  medium  of  zinc  phosphate  holding  together  zinc  oxid 
granules. 

The  first  class  of  oxyphosphates,  known  as  the  basic  zinc  phosphates, 
has  been  divided  into  two  classes  according  to  the  modifiers  in  solution 
in  the  phosphoric  acid,  one  known  as  alkaline  and  the  other  as  non- 
alkaline.  The  liquid  portion  of  the  alkaline  cements  differs  from  that 
of  the  non-alkaline  in  the  quantity  of  sodium  phosphate  it  contains. 
When  metaphosphoric  acid  is  combined  with  sodium  phosphate  the 
former  takes  on  a  smooth,  glassy  consistency,  and  is  known  as  glacial 
phosphoric  acid,  although,  as  suggested  by  Dr.  Ames,  it  is  in  reality 
orthophosphoric  acid  and  orthophosphate  of  sodium,  as  a  result  of 
effecting  the  combination  in  the  presence  of  water.  The  addition  of 
this  sodium  salt  aids  very  materially  in  handling  and  working  the  acid, 


29S  PLASTICS 

but  it  makes  a  soft,  porous  cemeutiu*^  medium.  Other  metals  than 
the  alkaline  group  have  been  added  to  the  phosphoric  acid,  prin- 
cipally in  the  form  of  phosphates,  to  form  an  improved  })roduct  much 
less  porous  than  the  alkaline  cement.  Not  all  of  the  sodium  has  been 
discarded  as  some  analyses  show.  Some  of  the  good  (jualities  of  the 
sodium  have  been  retained  apj)arently,  by  sul)stitutnig  such  metals  as 
magnesium,  aluminum,  silver,  zinc,  and  copper  for  a  portion  of  the 
sodium.  The  powder  portion  of  the  basic  zinc  phosphates  contains 
other  materials  than  zinc  oxid,  some  of  which  are  added  for  the  pur- 
pose of  pigmenting  and  some  for  the  improvement  of  the  integrity  of  the 
cementing  medium.  Oftentimes  these  materials  found  as  modifiers  in 
the  powder  portion  are  partially  or  wholly  insolu])le  in  the  liquid  portion. 
In  this  case,  other  things  being  equal,  the  cement  mass  would  resist 
attrition  somewhat  better. 

The  presence  of  partially  or  wholly  insoluble  substances  in  the  powder 
portion  of  these  cements  cannot,  however,  be  taken  as  a  guide  to  the 
property  of  resistance  to  attrition.  Like  sodium  phosphate,  they  can 
hardly  he  dispensed  with  entirely,  except  in  cements  used  for  crown-, 
bridge-  and  inlay-work,  and  then  their  elimmation  is  questionable.  Of 
such  substances  the  oxids  of  aluminum  and  silicon  are  notable. 

Substances  which  are  known  to  hasten  or  retard  the  setting  proper- 
ties of  these  cements  are  added  in  small  quantities  to  the  powder  as  well 
as  to  the  liquid  portions.  Among  such  materials  are  calcium  oxid  and 
sodium  phosphate,  the  former  hastening  and  the  latter  retarding  the 
setting  property.  The  properties  may  be  modified  widely  l)y  the  treat- 
ment given  the  diflFerent  oxids,  especially  zinc  oxid.  Zinc  oxid  may  be 
prepared  by  heating  zinc  hydroxid,  the  loss  of  water  converting  it  into 
the  oxid.  The  same  compound  may  be  prepared  by  igniting  metallic 
zinc  in  air.  Zinc  oxid  which  has  been  heated  comparatively  little  will 
make  a  soft  powder  and  a  sticky  cement,  while  if  the  zinc  oxid  is  cal- 
cined a  great  deal  it  is  flint-like  and  makes  a  less  sticky  cement.  This 
is  taken  into  consideration  in  the  production  of  the  basic  zinc  cements, 
some  products  appearing  to  contain  two  or  three  grades,  as  regards  the 
amount  of  calcining. 

The  second  class  of  oxyphosphates,  known  as  oxyphosphates  of 
copper,  are  similar  in  construction  to  the  basic  zinc  phosphates,  and 
what  has  been  said  of  modifiers  in  the  powder  and  licjuifl  portions  of 
the  basic  zinc  compounds  applies  equally  to  this  class.  (yenerally 
speaking,  they  differ  from  the  basic  zinc  compounds  l)y  having  oxid  of 
copper  for  the  base  of  the  powder  instead  of  oxid  of  zinc. 

The  third  class  of  oxyphosphates,  known  as  silicate  cements,  differ 
from  the  basic  zinc  compounds,  by  being  composed  of  oxids  of  other 
metals  than  zinc,  with  phosphoric  acid.  Among  such  metals  may  be 
mentioned  beryllium,  calcium,  aluminum,  and  silicon.  Since  even  le.ss 
work  has  been  done  with  this  class  of  cements  than  with   the  other 


CEMENTS  299 

classes  it  is  uncertain  wliat  the  li(|ni(l  or  ])()W(ler  jjortion  will  eventually 
be.  It  is  clainied  (hat  a.  certain  well-known  j)ro(luct  has  aluminum 
phosphate  in  large  quantities  and  zinc  phosphate  in  small  quantities  in 
its  phosphoric  acid.  H.  Carlton  Smith  stated  in  a  paper  before  the 
American  Academy  of  Dental  Science  at  Boston,  Fel)ruary  7, 1900,  that 
he  believed  these  claims  were  faithfully  carried  out.  During  the  last 
year  the  writer  has  examined  several  of  these  products,  and  found  the 
one  referred  to  l)y  Dr.  Smith  very  constant  in  composition  and  to  con- 
tain the  ingredients  claimed  by  its  promotors. 

Some  other  silicate  cements  have  appeared  to  differ  somewhat  from 
the  one  mentioned,  both  in  the  liquid  and  the  powder  portions,  the 
greatest  difference  being  in  the  quantity  of  beryllium.  While  in  general 
terms  the  base  of  nearly  all  cement  liquids  is  phosphoric  acid,  and 
the  base  or  foundation  of  the  powder  portion  is  an  oxid  of  a  metal,  it  is 
no  assurance  that  the  compounds  are  not  very  complex  bodies  involving 
intricate  chemistry.  The  virtue  of  almost  any  of  these  compounds  is  so 
dependent  upon  some  particular  modifiers  of  oxid  of  zinc  and  phos- 
phoric acid  that  the  use  of  other  liquids  and  powder  than  those  intended 
by  the  manufacturer  means  certain  disappointment  to  the  user.  For  this 
reason  it  is  never  safe  to  substitute  for  either  the  liquid  or  powder  of  a 
given  make  the  liquid  or  powder  of  another  make.  This  is  also  true 
with  different  classes  of  oxyphosphates  from  the  same  maker. 

A  given  phosphoric  acid  of  a  given  concentration  will  combine  with 
certain  of  these  metallic  oxids  and  produce  a  compound  of  a  certain 
insolubility,  possessed  of  certain  working  qualities  and  capable  of  a 
minimum  of  change  in  volume.  If  phosphoric  acids  of  other  concen- 
trations or  phosphoric  acid  containing  the  phosphates  of  other  metals 
be  substituted  a  change  of  properties  very  detrimental  to  the  product 
is  likely  to  occur. 

Attention  may  again  be  directed  to  the  fact  that  phosphoric  acid  for 
certain  of  these  cements  contains  non-alkaline  metallic  phosphates 
almost  to  the  point  of  saturation;  this  is  necessary  in  order  to  bring- 
about  the  desired  qualities  of  the  cement.  Certain  of  the  newer 
products  are  compounded  in  this  w^ay.  In  addition,  some  of  the  slow- 
setting  cement  liquids  contain  the  alkaline  phosphate  of  sodium,  which 
partially  neutralizes  this  tri-basic  acid,  assuming  that  orthophosphoric 
acid  is  used.  Such  a  phosphoric  acid  is  loaded  to  the  fullest  extent  with 
modifiers,  and  is  apt  to  crystallize  on  standing.  To  avoid  this  crystalli- 
zation. Dr.  Ames  conceived  the  idea  of  furnishing  his  cements  com- 
pounded for  quick  setting  and  furnishes  extra  some  of  the  acid  prepared 
with  phosphates,  to  retard  the  setting  and  add  a  little  to  the  adhesive 
properties,  etc.     This  he  calls  "flux." 

Some  interesting  phenomena  usually  occur  in  the  "loading"  of  phos- 
phoric acid  and  in  neutralizing  it  with  sodium  salts.  Orthophosphoric 
acid  is  theoretically  a  tri-basic  acid,  and  forms  mono-basic,  di-basic,  and 


300 


PLASTICS 


Fig.  309 


tri-hasic  suits,  the  first  two  l)t'iiii;  ai-id  to  litmus  and  the  latter  alkaline 
with  sodium.  It  may  be  seen,  however,  with  the  aid  of  litnnis,  that 
sodium  carbonate  of  varyin<;  dilutions  will  brinfj^  about  the  transition 
from  aeid  to  alkali  so  gradually  that  no  definite  i|uantity  can  be  said  to 
neutralize  an  axjueous  solution  of  phosphoric  acid.  '^I'he  following 
e(|uation  indicates  the  amount  of  sodium  carbonate  that  would  be  ex- 
pected to  neutralize  phosphoric  acid:  IlgPO^  +  3Na()II  =  NagPO^^- 
SHjO;  experiment,  however,  sliows  that  approximately  one-half  the 
quantity  indicated  by  the  fornuda  is  all  that  is  necessary  to  bring  about 
an  alkaline  test  with  litmus. 

Another  phenomenon  accompanies  the  use  of  varying  dilutions  of 
sodium  carbonate.  After  a  given  quantity  of  sodium  carbonate  has  i)een 
ascertained  which  will  neutralize  phosphoric  acid  it  is  found  necessary  to 
alter  this,  with  changes  in  temperature  and  changes  in  dilution  of  the 
sodium  salt.  These  phenomena  appear  to  be  due  to  the  difference  in 
dissociation  of  the  three  hydrogens  of  phos- 
phoric acid.  Ostwald  has  stated  that  not  only 
does  the  dissociation  HgPO^  =  H  +  H.^P(  )^  occur 
comparatively  easily,  but  in  measural)le  amount. 
The  further  dissociation  H2PO,  =  H  +  HPO,  he 
states  takes  place  only  in  a  very  slight  degree, 
and  the  third  dissociation,  IIP()^  =  H  +  PO^, 
is  exceedingly  slight.  This  seems  to  account 
for  these  phenomena  reasonably  well  when 
phosphoric  acid  and  sodium  carl)onate  are 
used,  but  when  phosphoric  acid  is  loaded  to, 
or  nearly  to,  saturation  with  one  or  more  modi- 
fiers, and  the  setting  qualities  of  a  cement  made 
from  it  seem  to  demand  the  introduction  of 
alkaline  phosphate,  certain  phenomena  a])pear 
which  are  less  easily  explained.  It  would  seem  that  the  liquid  portion 
of  cements  thus  compounded  would  rarely  ever  withstand  the  vicissi- 
tudes to  which  they  are  subjected. 

It  is  found  that  if  certain  precautions  are  observed,  most  cement 
liquids  stand  for  a  time  without  crystallization.  Any  portion  of  the 
cement  lifjuid  that  is  subjected  to  the  changes  in  humidity  of  most 
rooms  that  occurs  with  the  change  from  natural  to  artificial  heat  will 
have  a  strong  tendency  to  crystallize.  When  crystallization  has  once 
begun,  it  tends  to  spread  to  any  uncrystallized  portion  and  upon  newly 
made  liquid  of  the  same  composition.  When  the  ordinary  bottle, 
either  with  rubber  or  glass  stopper,  is  used,  there  is,  even  with  care,  the 
chance  of  leaving  some  of  the  liquid  exposed  to  the  air  around  the  neck 
of  the  ])()ttle.  This  maybe  avoided  somewhat  by  transferring  the  li(|uid 
from  the  container,  as  it  is  purchased,  to  the  telescoping  cap  bottle 
(Fig.  309).      This  requires  less   care   to   prevent   some   of   the   liquid 


CEMENTS  301 

remainino-  around  the  neck  exposed  to  the  air.  A  further  precaution  is 
to  he  ohserved  when  removing  tlie  h(juid  from  the  bottle.  Only  a 
pn-fccfl]/  cicdii  glass  dropper  shoidd  be  us(>d.  A  non-corrodible  spatula 
may  safely  be  used  if  it  has  not  previously  been  employed  to  remove 
powder  from  the  bottle,  and  is  free  from  any  other  foreign  substance 
which  by  combination  with  the  acid  would  interfere  with  the  equilibrium 
of  composition  in  the  licjuid. 

Several  modifications  may  be  made  in  the  setting  qualities  and  strength 
of  a  cement  by  the  physical  condition  of  the  powder  portion.  A  given 
coarse  powder  mixed  with  a  phosphoric  acid  solution  may  be  slow  setting; 
the  same  powder  when  reduced  to  a  finer  state  may  be  rapid  setting 
because  of  the  increased  surface  of  the  zinc  oxid  presented  for  action  to 
the  phosphoric  acid  solution.  An  analogous  process  occurs  in  most  plas- 
tics, except  some  of  the  alloys,  which  would  also  act  this  way  were  it  not 
for  the  annealing  which  takes  place  more  rapidly  with  the  finer  cut  alloy. 
Some  cements  which  are  supposed  to  be  alike  will  act  differently,  on 
account  of  this  difference  in  the  fineness  or  coarseness  of  the  powder 
portion.  This  is,  obviously,  analogous  to  other  plastics.  Each  com- 
bination has  only  a  given  coarseness  and  fineness  which  will  yield  given 
physical  characteristics.  The  strength  of  cements  may  be  modified  by 
the  size  of  the  granules  of  their  powder  portion.  In  some  cements 
the  adhesive  property  seems  to  have  been  developed  to  the  slight  detri- 
ment of  strength,  such  cements  being  intended  for  setting  inlays,  etc. 
The  powder  portion  of  these  inlay  cements  is  often  much  finer  than  the 
powder  of  the  same  cement  used  for  fillings.  There  appears  to  be  a 
limit,  however,  to  the  fineness  of  powders,  strength  falling  off  if  they  are 
extremely  fine.    Strength  likewise  decreases  if  the  powder  is  very  coarse. 

Another  modification  of  these  cements  may  result  from  an  exposure 
of  the  powder  portion  to  the  atmosphere  of  the  room.  The  oxids  will 
hydrate  and  absorb  carbon  dioxid  and  become  hydrated  carbonates  of 
the  metals  of  which  they  are  composed. 

It  is  doubtful  whether  the  products  of  the  best  manufacturers  contain 
impurities  which  appreciably  modify  the  behavior  of  these  cements. 
Until  recently,  however,  impurities  have  not  been  watched  for  with  as 
much  care,  and  both  liquid  and  powder  have  been  subject  to  them. 
Much  of  the  irritation  to  the  pulp  from  cements  has  been  attributed  to 
the  presence  of  arsenic  as  an  impurity.  Chemical  investigation  has 
proved  that  while  arsenic  is  invariably  present  as  an  impurity  in  oxid 
of  zinc  it  is  in  the  form  of  insoluble  zinc  arsenite  and  inert  to  the  pulp 
tissue.  Impurities  have  been  found  in  the  liquid  of  the  cheaper  cements, 
but  the  liquids  of  the  better  products  contain  little  or  nothing  that  was 
not  intentionally  placed  there  by  the  manufacturer. 

A  commerical  glacial  phosphoric  acid  has  a  somewhat  variable  com- 
position. It  is  the  metaphosphoric  acid  containing  some  sodium  phos- 
phate, and  because  of  its  hygroscopic  properties  a  varying  amount  of 


302  PLASTICS 

water,  which  slowly  converts  the  metaphosphoric  acid  to  orthophos- 
phoric  acid.  The  liquids  of  the  better  cements,  however,  are  not  com- 
nierical  products.  They  contain,  very  often,  a  number  of  ingredients 
in  small  (juantities,  but  the  effect  of  each  ingredient  upon  the  integrity 
of  the  cement  mass,  its  solubility,  its  volumetric  change  during  setting, 
and  rapidity  of  setting,  is  known.  A  bottle  of  carefully  prepared  cement 
li(]uid  may,  after  standing  for  some  time,  appear  somewhat  turbid 
toward  the  bottom  of  the  bottle  and  appeared  contaminated  with  im- 
purities in  some  or  all  of  the  constituents.  This  is  often  observed  when 
a  portion  of  the  bottle  of  licjuid  has  been  used.  Such  phenomena  are 
usually  due  to  the  formation  of  layers  of  different  densities,  and  the 
residue  of  a  bottle  of  licjuid  almost  always  has  a  higher  specific  gravity 
than  the  liquid  formerly  had.  Such  liquids  do  not  indicate  the  presence 
of  impurities  as  much  as  the  attempt  on  the  part  of  the  maker  to  com- 
bine the  properties  of  a  number  of  substances,  the  result  being  a  liquid 
which  will  not  withstand  the  vicissitudes  to  which  it  is  subjected. 

Properties  and  Uses  of  Cements. — The  better  products  are  tested 
for  volumetric  change  at  and  subsequent  to  insertion,  in  the  same 
manner  dnd  with  the  same  instruments  as  alloys.  The  Wedelstaedt 
steel  test-tube  is  used  as  a  matrix  to  retain  the  cement,  and  a  micrometer 
such  as  shown  in  P^ig.  300  will  permit  subjecting  the  filling  to  a  water 
bath  at  any  stage  during  the  setting  by  placing  the  micrometer  in  a 
small  container  at  the  time  of  taking  the  first  reading  and  allowing 
water  to  flow  into  the  eontainer  at  the  desired  time. 

It  is  very  esential  that  cements  be  tested  both  dry  and  wet;  with 
alloys  no  action  with  the  water  will  modify  change  in  volume  or 
strength.  Not  so  w^ith  the  cements.  A  cement  which  will  shrink 
markedly  when  dry  may  expand  very  much  if  subjected  to  a  water 
bath  during  the  earlier  stages  of  the  setting.  I^ike  alloys,  the  best 
cements  expand  slightly.  The  expansion  of  the  cements  at  and  subse- 
quent to  insertion  may  be  modified  by  at  least  two  factors,  viz.,  the  stiff- 
ness of  the  mix  and  the  time  that  moisture  is  allowed  access  to  the  cement. 

If  moisture  is  kept  from  a  cement  intended  to  be  hydraulic  there 
may  be  no  expansion,  while  if  it  is  subjected  to  moisture  early  in  the  set- 
ting it  may  expand  several  points.  With  a  stiff'  mix,  as  used  for  fillings, 
less  expansion  is  likely  than  when  less  powder  is  incorporated  and  the 
consistency  appears  about  midway  between  that  of  a  cement  mixed  for 
cementing  inlays,  bands,  etc.,  and  that  mixed  for  a  filling.  The  creamy 
mix,  as  a  rule,  gives  the  greatest  expansion,  although  there  must  not  be 
too  little  powder,  as  is  often  the  case  when  mixing  for  inlays,  etc.,  or 
there  will  be  a  slight  shrinkage.  The  strength  of  the  cements  is  modi- 
fied to  even  a  greater  degree  by  the  manner  of  mixing  than  is  the 
strength  of  alloys.  Almost  any  strength  may  be  obtained  from  300 
pounds  to  1500  pounds  on  a  cylinder  j  inch  high  and  ^  inch  in  diam- 
eter.    As  in  the  case  of  alloys  there  is  no  definite  time  during  which 


CEMENTS  303 

cements  will  resist  a  given  force.  Some  of  the  present  cements,  how- 
ever, iipj)ear  to  change  less  in  strength  than  most  alloys  do  if  they  are 
kept  from  the  oral  media.  The  union  between  many  of  the  oxids  and 
modified  phosphoric  acid  solutions  is  effected  much  more  energetically, 
and  in  consecjuence  is  less  likely  to  result  in  the  menstruum  acting 
upon  the  solid  under  ordinary  conditions.  It  is  nearly  impossible, 
however,  to  obtain  a  perfect  chemical  product  from  the  cements  under 
the  manipulation  given  them  by  dentists. 

Attention  has  already  been  called  to  the  excess  of  zinc  oxid  granules 
which  is  always  present  when  cement  is  mixed  for  a  filling.  When  it 
is  mixed  for  cementing  bands,  inlays,  etc.,  this  is  not  always  true. 
Wlien  cements  are  subjected  to  the  oral  media  the  integrity  of  the 
cement  mass  usually  suffers,  especially  in  the  case  of  the  basic  zinc 
phosphates  and  oxyphosphate  of  copper,  both  of  which  are  subject  to 
the  solvent  action  of  basic  and  acid  products  of  the  mouth.  The  presence 
of  lactic  acid  in  the  mouth  due  to  the  process  of  fermentation  and  its 
action  upon  the  basic  zinc  phosphates  and  oxyphosphates  of  copper 
are  well  known.  Ammonia  water  also  dissolves  some  of  the  oxids, 
notably  zinc  oxid,  and  as  it  is  doubtful  if  a  basic  zinc  phosphate  is  ever 
composed  of  the  exact  combining  weights  to  form  a  basic  phosphate,  it 
is  not  unreasonable  to  suppose  that  some  of  the  basic  phosphate 
cements  will  disintegrate  as  a  result  of  this  action.  Ammonia  infre- 
quently occurs  as  such  in  the  mouth,  but  the  ammonium  salt  in  the 
form  of  chlorid  does,  and  its  action  upon  the  basic  oxyphosphates  much 
resembles  that  of  ammonia,  although  it  is  slower. 

Much  is  claimed  for  the  insolubility  of  the  newer  products  known 
as  silicate  cements,  but  their  origin  is  so  recent  and,  with  one  or  two 
exceptions,  they  are  so  changeable  in  composition  that  few  data  of  a 
practical  nature  are  obtainable.  Laboratory  tests,  however,  are  en- 
couraging, but  before  being  accepted  they  must  be  verified  by  practical 
tests.  Dr.  Joseph  Head^  has  pointed  out  that  any  test  which  might  be 
applied  in  the  laboratory  is  only  a  guide  to  the  solubility  of  cements  in 
different  mouths.  He  has  shown  that  a  1  to  500  lactic  acid  and  water 
solution  will  turn  tooth  enamel  white  in  one-half  hour,  while  a  1  to  500 
lactic  acid  and  saliva  may  not  attack  it  appreciably  for  weeks,  and  yet 
the  latter  solution  may  turn  blue  litmus  brilliantly  red  and  possess  an 
acid  taste.  This  phenomenon  he  attributes  to  the  restraining  power  of 
saliva  upon  lactic  as  well  as  other  acids.  He  also  points  out  that  this 
property  of  the  saliva  varies  in  different  individuals  and  in  the  same 
individuals  at  different  intervals. 

Dr.  Klrk^  has  pointed  out  that  mucin  is  probably  the  protective 
element  in  the  saliva  which  prevents  the  action  of  highly  dilute  acids 
upon  the  teeth.      He  has  also  called  attention  to  a  quite  analogous 

1  Dental  Cosmos,  August,  1908.  '  Ibid.,  vol.  lii,  p.  735. 


304 


PLASTICS 


p/icnomenoii,'  in  wliicli  lie  .shows  tliat  hoth  acid  and  basic  sodium 
phosphate  may  exist  in  the  same  saliva  and  not  l)e  neutralized  by  each 
other.  Thus,  it  seems  that  the  solubility  of  the  cements  depends  more 
upon  the  cotidition  of  f/ic  salivd  than  tlie  mere  presence  of  any  solvent 
coming  from  the  saliva,  products  of  fermentation,  or  the  focxl. 

The  uses  to  which  the  l)a.sic  zinc  phosphates  may  be  put  are  about  as 
varial)le  as  are  the  cases  re(juiring  the  services  of  the  dentist.  The 
popularity  of  the  inlay  method  of  filling  teeth  has  increased  its  use- 
fulness in  retaining  fillings.  The  increased  amount  of  orthodontia 
done  from  year  to  year  has  demanded  more  of  this  material  for  the 
retention  of  bands,  etc.  Its  use  as  a  filling,  how^ever,  is  probably  as 
limited  as  ever,  it  being  regarded  as  a  temporary  filling  in  every  sense. 
Many  specimens  have  been  exhibited  in  which  these  cements  have 
served  as  a  filling  for  several  years,  but  such  cases  are  the  exception 
rather  than  the  rule.  These  cements  are  valuable  in  temjjorary  opera- 
tions on  the  teetli  of  adults  and  children.  They  are  indispensable  in 
retaining  fixed  bridge-work  and  crowns  and  are  invaluable  in  elimi- 
nating undercuts  and  forming  the  base  of  cavities  for  all  kinds  of  fillings. 


The  oxyphosphate  of  copper  cements  may  be  used  like  the  basic  zinc 
phosphates,  although  they  are  more  applicable  to  the  teeth  of  children 
and  of  such  adults  as  require  the  salutary  effect  of  the  c-opper  salts. 
These  cements  are  much  more  l)land  than  either  the  basic  zinc  phos- 
phates or  the  silicate  cements.  \Mien  placed  near  a  pulp  or  the  peri- 
dental tissues  these  copper  salts  seem  to  exert  a  l)eneficial  rather  than  a 
destructive  influence,  as  also  in  the  pulp  chambers  and  canals  of  decidu- 
ous teeth.  The  silicate  cements  have  not  been  in  use  long  enough  to 
enable  the  profession  to  judge  of  their  pro])erties  although  they  seem  to 
make  very  good  fillings.  They  are  almost  devoid  of  adhesiveness,  which 
excludes  them  from  use  for  retaining  bands,  inlays,  crowns,  bridges,  etc. 
They  are  much  more  translucent,  and  much  less  soluble  than  any  other 
cement  used  in  dentistrv. 


'  Dental  Cosmos,  April,  1907. 


CEMENTS 


305 


Mixing  of  Cement— To  mix   tlio  ))()\v(lor  and  lifpiid  j)ropcrly  they 
should  be  plaeed  upon  a  hirge  "'lass  slab  which  is  attaeiied  to  the  cabinet 


IB 


Fi(i.  :?ii 


^ 


or  a 


..  ^  thick  one  which  can  be  easily  grasped  with  the  hand  and  held 
still  during  the  mixing  (Fig.  310).     The  powder  and  liquid  should  be 
20 


;juo 


I'l.A.STlCS 


placed  some  distanee  apart,  so  that  a  small  amount  of  powder  can  he 
cut  into  the  amount  of  liquid  thoufjht  to  be  necessary  for  the  operation, 
with  a  large  iridio-platiiium  or  good  grade  German  silver  spatula,  if  the 


Fig.  312 


Ash's  agate-ended  plastic  instruments  for  inserting,  packing,  and  polishing  silicate  cement. 


CEMENTS  307 

cement  be  a  l)asic  zinc  pliosj)Iiate  or  oxypliospliate  of  copper.  If  the 
cement  be  a  silicate  cement  and  the  operation  require  tlie  translucency 
obtainable  with  these  bodies,  a  bone  or  agate  spatula  should  be  used,  but  in 
no  case  should  a  steel  s{)atula  be  employed.  Iridioplatinum  is  probably 
the  best  material  for  a  spatula  in  opeiations  where  a  slight  modification 
of  color  is  not  objectionable,  although  it  is  doubtful  if  there  is  sufficient 
abrasion  from  this  kind  of  spatula  a})preciably  to  modify  the  color  of 
the  silicate  cements.  The  objection  to  most  agate  and  bone  spatulas  is 
their  shape,  which  will  not  enable  the  operator  to  form  a  thorough  mix 
in  the  time  at  his  disposal  before  the  cement  begins  to  set.  The  most 
practical  spatula  for  the  basic  zinc  phosphates  and  oxyphosphates  of 
copper  seems  to  be  one  of  good  German  silver.  It  is  not  attacked  ener- 
getically by  the  phosphoric  acid  solution  and  is  not  abraded  sufficiently 
to  be  injurious  to  an  appreciable  extent  to  these  cements.  The  reverse 
is  true  when  a  steel  spatula  is  used,  as  phosphate  of  iron  usually  is 
detrimental. 

Each  addition  of  powder  should  be  cut  into  the  liquid  in  a  clean  man- 
ner and  mixed  until  a  thorough  incorporation  of  the  two  is  in  evidence 
before  another  addition  is  made.  This  should  be  continued  until  the 
desired  consistency  is  obtained.  For  retaining  inlays,  bands,  crowns, 
etc.,  the  mixture  must  be  of  a  consistency  to  flow  quite  freely.  For 
fillings  the  mass  should  be  of  a  putty-like  consistency,  which  can  be 
packed.  The  demands  of  the  dentist  are  so  varied  that  the  consistency 
of  the  mass  before  it  is  set  determines  the  amount  of  powder  to  be 
added  to  a  given  amount  of  liquid.  No  definite  proportions  can  be 
given  which  will  meet  the  requirements  of  all  cases.  The  silicate  cements 
and  oxyphosphates  of  copper  employed  principally  for  fillings  permit  of 
more  definite  proportions  than  the  basic  zinc  phosphates  which  are 
used  for  a  variety  of  purposes.  There  is  one  exception  to  mixing 
cements  to  a  putty-like  consistency  for  fillings,  viz.,  in  the  use  of  the 
oxyphosphates  of  copper.  These  cements  appear  to  develop  a  greater 
density  and  to  disintegrate  less  easily  when  mixed  to  a  creamy  con- 
sistency, although  in  this  condition  they  are  not  always  as  easily  in- 
serted into  a  cavity.  It  is  often  necessary  to  vary  the  consistency  with 
the  temperature  of  the  room  and  that  of  the  mixing  slab.  Since  heat 
facilitates  chemical  change,  it  is  often  necessary  to  make  the  mix-  a  little 
thinner  in  hot  weather  or  if  the  slab  is  quite  warm. 

All  instruments  used  in  mixing  cements  should  be  scrupulously  clean. 
Foreign  substances  which  would  not  injure  an  alloy,  might  work  marked 
injury  to  a  cement.  The  presence  of  moisture  before  the  cement  has 
been  placed  may  work  an  injury  to  the  quality  of  the  cement  formed, 
but  with  the  newer  products  it  is  often  desirable  to  allow  moisture  to 
have  access  to  the  fillings  after  it  has  been  placed.  This  applies 
obviously  only  to  the  cements  compounded  for  this  purpose  and  desig- 
nated as  hydraulic  cements. 


308  PLASTICS 

Nearly  all  basic  zinc  phosphates  and  ()xyph()Sj)hatcs  of  co])per  in  use 
at  present  are  conij)ouiKle(l  so  as  to  act  properly  when  subjected  to 
moisture  almost  immediately  after  hein^  j)laced.  A  few  of  the  older 
products,  however,  nmst  be  protected  from  moisture  for  hours  after 
being  placed.  This  may  be  done  by  covering  them  with  wax  or 
paraffin.  The  silicate  cements  are  very  susceptible  to  moisture.  A 
mere  trace  seems  to  injure  them  markedly,  even  after  they  have  been 
placed  several  minutes.  These  cements  should  be  inserted  in  the  entire 
absence  of  moisture  and  covered  for  several  hours  with  some  protective 
material.  Waxes  and  paraffins  are  the  principal  substances  adopted 
for  this  purpose. 

The  writer  has  had  the  greatest  success  with  thesticky  waxinade  after 
the  formula  of  Dr.  Fred.  A.  Peeso,  consisting  of  pure  white  wax,  It)  parts; 
white  resin  (colophony),  powdered,  3  parts;  gum  danmiar,  powdered, 
3  parts.  It  is  light  in  color  and  extremely  adhesive,  the  latter  (juality 
being  of  the  greatest  importance  in  protecting  the  filling  from  moisture. 

What  has  been  said  of  packing  alloys  is  also  true  of  the  cements, 
with  the  exception  of  the  oxyphosphates  of  copper,  some  of  which  are 
best  mixed  to  a  creamy  consistency  and  often  most  readily  inserted 
without  a  matrix.  The  basic  zinc  phosphates  and  silicate  cements  are 
best  inserted  with  a  matrix  if  the  cavity  be  a  proximal  or  proximo- 
occlusal  one.  All  cavities  which  are  not  four  walled  should  be  converted 
into  such  by  the  use  of  the  matrix. 

The  same  matrices  used  for  alloys  may  be  used  with  the  basic  zinc 
phosphates,  the  majority  being  thin  steel.  Unlike  the  steel  spatula,  the 
steel  matrix  does  little  or  no  harm  because  there  is  little  abrasion,  and, 
l)esides,  the  acidity  of  the  liquid  has  been  lessened  by  the  basic  powder 
portion.  German  silver  and  copper  may  also  be  used  for  matrices  with 
the  basic  zinc  phosphates  and  oxyphosphates  of  copper,  but  not  always 
with  the  silicate  cements.  They  should  usually  be  inserted  with  a  cellu- 
loid matrix.  If  there  is  slight  or  no  abrasion  between  the  silicate  cement 
and  metal  matrix,  little  or  no  harm  results;  but  if  some  abrasion  occurs, 
discoloration  and  injury  to  the  integrity  of  the  cement  are  apt  to  take 
place.  The  basic  zinc  phosphates  and  oxyphosphates  of  copper  may  be 
packed  and  trimmed  with  the  same  instruments  as  those  used  for  alloys, 
although  it  is  better  not  to  use  instruments  with  serrations. 

Fig.  311  shows  very  desirable  forms  of  instruments  for  use  in  hand- 
ling these  cements.  One  or  two  of  the  ball-shaped  instruments  should 
be  ground  so  that  only  one-half  of  the  ball  is  left,  to  make  them  flat 
instead  of  round  packing  instruments.  An  amalgam  plugger  or  two 
may  have  the  serrations  ground  off,  leaving  them  flat  and  smooth  so 
that  the  cement  will  not  adhere  so  tightly  to  the  jiacking  surface  of  the 
instrument.  The  silicate  cements  may  be  packed  and  trimmed  with  steel 
instruments  if  care  is  exercised  not  to  rub  the  instrument  over  the  cement. 
The  makers  of  these  products  generally  condemn  the  use  of  steel  instru- 


GUTTA-PERCHA 


309 


merits,  because  in  unskilled  hands  the  result  is  a  discolored  filling. 
Agate,  bone,  or  tortoise-shell  instruments  (1^'igs.  312  and  313)  are  invari- 
ably advocated,  although  according  to  the  general  judgment  they  are 
not  delicate  enough  to  permit  the  technique  necessary  for  good  results. 
If  the  packing  is  done  with  as  little  rubl)ing  as  possible,  steel  instru- 
ments may  be  used  w^ith  little  danger  of  discoloration. 

The  same  is  true  in  trimming.  The  instruments  should  l)e  sharp 
enough  to  avoid  unnecessary  friction.  The  agate  and  bone  instruments 
advocated  by  their  makers  are  practical  for  large  cavities  where  the 
margins  extend  well  from  the  proximate  surfaces  of  the  teeth,  and  for 
occlusal,  buccal,  and  lingual  cavities. 

The  cements  may  be  finished  with  paper  or  cloth  strips  or  disks  as 
soon  as  they  have  hardened,  varying  with  different  cements,  the  manner 
of  mixing,  and  the  presence  or  absence  of  water. 

Fig.  313 


Tortoise-shell  points  to  be  mounted  on  any  instrument  handle. 


Care  should  be  exercised  in  the  selection  of  strips  or  disks  for  use 
on  the  silicate  cements.  If  the  abrasive  material  on  the  strip  or  disk  be 
dark  colored  there  is  liable  to  be  a  surface  discoloration,  due  to  the 
incorporation  of  the  abrasive  material  into  the  surface  of  the  filling. 

Steel  burnishers  used  to  finish  metal  fillings  should  not  be  used  to 
finish  any  cement  filling  after  the  cement  has  hardened  sufficiently  to 
abrade  them  while  rubbing  them  over  the  filling.  More  importance  is 
attached  to  the  finish  given  the  silicate  cements  than  upon  the  basic 
zinc  phosphates  or  oxyphosphates  of  copper.  Owing  to  the  solubility 
of  the  two  latter  classes  a  finish  will  last  but  a  short  time. 

It  is  claimed  by  some  that  a  polished  surface  on  the  better  silicate 
cements  will  last  longer  and  aid  materially  in  preventing  an  alteration 
of  the  pigments  in  them.  This,  however,  is  a  recent  observation,  and 
has  not  been  verified  by  a  sufficient  number  to  warrant  the  acceptance 
of  this  theory.  Undoubtedly  a  polished  surface  will  more  closely  approxi- 
mate the  luster  of  the  enamel  and  make  a  more  finished  piece  of  work, 
but  if  the  stability  of  the  pigments  is  dependent  upon  a  polished  surface, 
even  to  a  slight  degree,  there  are  certain  to  be  discolored  fillings. 


310  FLASTIL'S 


GUTTA-PERCHA 


The  gutta-percha  of  commerce  is  the  concrete  juice  of  the  Isonanclra 
gutta,  an  evergreen  tree  of  the  order  of  Sapotaceae,  found  chiefly  in  the 
Mahiy  peninsula  and  arcliipelago.  Tlie  juice  is  secured  by  tajjping 
tlie  cambium  layer  of  the  tree  and  catching  the  juice  as  it  exudes. 
The  juice  thus  obtained  undergoes  many  processes  for  purification 
before  it  is  formed  into  sheets  as  seen  in  commerce  (see  works  on  (lUtta- 
percha),  and  several  more  before  it  appears  in  the  market  for  dental 
purposes. 

"The  purified  gutta-percha  probably  consists  of  a  hydrocarbon 
(pure  gutta)  having  the  formula  CioHie;  albane,  C40H64O3;  and  a  variable 
compound  named  guttane.  Pure  gutta  possesses  all  the  good  qualities 
of  gutta-percha  in  a  much  enhanced  degree,  becoming  soft  and  plastic 
on  heating  and  hard  and  tenacious  on  cooling  without  being  in  the  least 
brittle.  The  resins  seem  to  be  simply  accessory  components  which  have 
a  decidedly  detrimental  effect  when  they  preponderate.  Water,  wood 
fibers,  bark,  sand,  etc.,  occur  as  mechanical  impurities  of  gutta-percha." 
(Obach.) 

It  will  be  seen  that  gutta-percha  resembles  rubber  in  composition, 
since  it  consists  chiefly  of  a  hydrocarbid,  in  which  the  two  elements, 
carbon  and  hydrogen,  are  present  in  similar  proportions.  Gutta-percha 
resembles  rubber  also  in  its  origin,  both  coming  from  the  milky  juice 
of  certain  trees,  although  some  claim  a  superior  quality  of  gutta  is 
obtained  by  processes  of  extraction  from  the  dried  leaves  and  buds. 
Apart  from  these  similarities,  the  two  substances  are  not  so  very 
similar.  Rubber  is  a  very  elastic  body,  i.  e.,  it  is  capable  of  returning 
to  its  original  form  when  a  mechanical  force  causes  it  to  undergo  a 
change.  Gutta-percha,  on  the  other  hand,  has  a  tendency  to  preserve 
the  change  in  form  produced  on  it  by  the  action  of  similar  forces. 
Rubber  containing  no  sulphur  softens  under  heat,  as  does  gutta-percha, 
but  preserves  its  elasticity  if  the  heat  be  kept  within  certain  limits; 
beyond  a  definite  degree  of  heat  its  physical  and  chemical  properties 
are  altered.  Gutta-percha,  on  the  contrary,  under  heat  which  does 
not  exceed  110°  C,  is  very  plastic  and  malleable  and  preserves  on 
cooling  the  appearance  and  shapes  which  have  been  given  to  it  while 
in  the  plastic  state.  Several  other  differences  between  the  two  exist, 
such  as  the  action  of  light,  moisture,  and  air,  the  action  of  suli)hur  on 
the  two,  their  non-conducting  properties,  etc.,  though  the  principal 
difference  in  this  connection  is  the  one  in  their  elasticity. 

Because  gutta-percha  preserved  the  shape  given  to  it  exceedingly 
well  for  a  material  of  its  nature,  it  was  introduced  as  a  filling  material 
into  dental  practice,  according  to  Dr.  Kirk,  about  the  year  1847.  Since 
that  time  several  secret  preparations  have  been  introduced,  all  of  which 


GUTTA-FERCJIA  311 

have  probably  been  gutta-percha  to  which  other  substances  have  been 
added  for  tlie  purpose  of  cliangin<^  the  physical  properties  by  improv- 
ing the  desirable  ones  and  masking  or  destroying  the  undesirable  ones. 
One  of  the  first  to  appear  was  by  Dr.  Hill,  which  received  his  name. 
Several  analyses  of  Hill's  stopping  have  been  given,  all  of  which  are 
probably  untrustworthy.  Dr.  Herman  Prinz,^  however,  gives  the  for- 
mula of  Hill's  stopping  as:  Feldspar,  1  part;  quartz,  1  part;  quicklime,  2 
parts;  gutta-percha  base-plate,  a  sufficient  quantity  to  make  a  stiff  mass. 

Dr.  Prinz  does  not  give  his  authority  for  this  formula,  although  it 
would  seem  that  if  both  feldspar  and  quartz  were  added  it  would  be 
done  empirically.  Dr.  Kirk  has  said:  "  It  subserved  so  useful  a  purpose 
that  it  received  the  tribute  of  wide  imitation ;  in  fact,  the  white  gutta- 
percha preparations  of  the  present  day  had  their  foundation  in  this 
imitation."  Undoubtedly  the  present  gutta-perchas  and  their  modifi- 
cations have  gradually  developed  from  this  preparation,  in  the  same 
manner  that  other  filling  materials  have  become  very  complex  com- 
pounds as  a  result  of  years  of  study.  The  gutta-perchas  for  dental  use 
are  divided  into  three  classes  according  to  the  temperature  of  softening : 
"Low  heat,"  softening  below  200°  F. ;  "Medium  heat,"  becoming  plastic 
at  200°  to  212°  F.;  "High  heat,"  210°  to  220°  F.  The  three  kinds  are 
often  numbered  to  distinguish  them  from  each  other,  one  manufacturer 
assigning  No.  6|  to  the  low  heat,  No.  7f  to  the  medium  heat,  and 
No.  8^  to  the  high  heat  gutta-percha.  According  to  Kirk  the  low 
heat  gutta-percha  contains  about  1  part  by  weight  of  gutta-percha  to 
4  of  zinc  oxid ;  in  medium  heat  the  ratio  is  1  to  6  or  7 ;  and  in  the  high 
heat  specimens  the  gutta-percha  is  almost  saturated  with  zinc  oxid. 

In  some  of  the  products  materials  other  than  zinc  oxid  are  used  to 
mix  with  the  gutta-percha.  The  proportions,  however,  remain  about 
the  same.  Calcium  carbonate,  some  of  the  sulphates,  silica,  and  other 
oxids  are  among  the  substances  claimed  to  be  substituted  for  the  zinc 
oxid. 

Physical  Properties. — Gutta-percha  in  the  pure  state  is  almost  color- 
less, the  small  amount  of  coloration  varying  from  rose  to  grayish 
white.  It  is  inodorous  and  insipid.  It  is  naturally  cellular  in 
structure,  but  if  drawn  out  its  texture  becomes  fibrous  and  more 
resistant  lengthwise  and  less  transversely.  It  will  not  break  until  a 
load  of  about  25  kilograms  per  square  millimeter  has  been  applied  to 
it.  It  is  but  slightly  elastic.  It  is  a  very  good  non-conductor  of  both 
heat  and  electricity.  It  contracts  in  hardening,  i.  e.,  cooling.  Its 
density  varies  from  slightly  under  that  of  water  to  slightly  over  it, 
depending  upon  the  compression  given  to  it  in  forming  it  into 
sheets.  To  the  vital  tissues  it  is  very  bland.  Gutta-percha  which 
has  been  in  the   mouth  for   some  time  often  becomes  harder,  and 

*  Dental  Formulary,  p.  21. 


312  PLASTICS 

its  surface  porosity  is  increased.  Kirk  states  in  regard  to  these 
changes:  "The  increased  hardness  is  observed  in  such  situations  as 
those  in  which  putrefactive  decomposition  occurs;  that  is,  in  j)laces 
where  there  is  an  evohition  of  liydrogcn  sulphid;  the  gutta-])ercha  ap- 
parently undergoes  a  species  of  vulcanization.  It  becomes  somewhat 
porous  in  those  situations  where  the  formation  of  a  solvent  is  active 
(lactic  acid),  which  abstracts  the  soluble  zinc  oxid  from  the  mass. 
The  pink  variety  containing  the  insolu})le  mercury  sulphid  does  not 
become  porous,  but  wears  with  a  comparati\ely  smooth  surface 
when  subjected  to  attrition."  This  would  seem  to  explain  some  of 
the  changes  \evy  satisfactorily,  but  there  are  some  where  other 
explanations  would  seem  to  apply.  For  example,  gutta-percha  which 
has  been  exposed  to  air  and  light  becomes  friable  like  rosin,  and 
its  solubility  in  certain  reagents  is  increased.  If,  however,  the 
gutta-percha  be  submerged  in  water  no  perceptible  change  is  pro- 
duced. Oxygen  aided  by  light  is  supposed  to  be  the  factor  of  prime 
importance  in  this  change  and  as  a  result  the  process  is  generally 
spoken  of  as  oxidation,  although  some  refer  to  it  as  resinification,  since 
the  extent  of  the  change  depends  largely  upon  the  resin  present  in  the 
gutta-percha.  Thus,  it  would  seem  that  oxygen  produces  a  condition 
in  gutta-percha  quite  analogous  to  the  one  observed  by  Kirk  which 
he  has  attriljuted  to  the  action  of  sulphids.  In  both  cases,  however, 
whether  the  gutta-percha  be  in  the  mouth  or  out  of  it,  the  change  is 
apparently  what  he  has  called  "a  species  of  vulcanization."  What 
Kirk  states  regarding  the  porosity  of  the  surface  is  probably  true.  It 
would  seem,  however,  since  the  solubility  of  gutta-percha  in  alka- 
lies increases  with  oxidation,  that  there  was  a  chance  for  the  surface 
to  become  porous  in  the  absence  of  lactic  acid.  Gutta-percha  in  the 
normal  condition  is  insoluble  in  dilute  acids  and  concentrated  alkaline 
solutions.  It  is  solul)le  in  carbon  bisulphid,  chloroform,  coal-tar  oils, 
benzol,  boiling  ether,  and  oil  of  turpentine. 

Indications  for  Employment. — Gutta-percha  in  its  white  and  i)ink 
forms,  and  in  the  three  classes,  low,  medium,  and  high  heat,  is  used 
as  a  temporary  filling  material  for  both  the  temporary  and  perma- 
nent teeth.  Its  non-conductivity  makes  it  a  good  material  to  place 
near  the  pulp.  Conditions  are  met  in  which  the  use  of  gold,  amalgam, 
basic  zinc  j)hosphates,  and  silicate  cements  alone  is  contraindicated 
because  of  the  close  proximity  to  the  pulj).  In  such  cases  a  thin  layer 
of  gutta-percha  may  be  placed  over  the  pulp,  after  which  the  permanent 
filling  materials  may  be  inserted  without  serious  injury  to  the  pulp 
from  thermal  changes.  It  has  been  quite  a  common  practice  to  fill 
deep  undercuts  with  gutta-percha  and  cover  it  with  amalgam  or  cement, 
or  cement  and  gold,  but  recent  requirements  for  better  cavity  forma- 
tion seem  to  have  created  a  demand  for  a  harder  material,  and  as  a 
result  the  basic  zinc  phosphates  have  been  more  widely  used. 


GUTTA-PERCIIA  313 

Gutta-percha  is  generally  used  to  fill  the  pulp  chambers  of  devital- 
ized teeth,  hut  even  here  it  is,  as  a  rule,  conceded  better  jjractice  to 
confine  it  to  the  root  portion  of  the  pulj)  cavity,  and  to  fill  any 
remaining  })ortions  which  require  a  similar  plastic  material  with  one 
of  the  best  basic  zinc  phosphates.  It  has  been  used  extensively  for 
cervical  cavities  in  molars  and  bicuspids  which  do  not  extend  to 
the  masticating  surfaces,  but  the  demand  for  better  oral  hygiene  is 
such  that  this  practice  has  become  less  common  except  for  relatively 
temporary  operations.  It  has  been  used  for  all  classes  of  cavities  in 
the  temporary  teeth,  and  seems  often  to  be  practically  the  only  avail- 
able material  which  will  meet  the  requirements  of  these  cases.  There 
is  a  tendency,  however,  to  use  less  gutta-percha  in  the  temporary 
teeth  because  of  the  demands  of  orthodontists  for  the  retention 
of  normal  contact  when  restoring  proximate  portions  of  these  teeth. 
There  is  likewise  a  tendency  to  use  it  less  in  other  locations  in  the 
deciduous  teeth  for  the  reasons  previously  given  in  regard  to  better 
oral  hygiene. 

To  the  casual  observer  it  might  seem  from  this  that  there  was  little 
use  to  which  gutta-percha  might  be  put.  Such,  however,  is  not  the  case. 
Instead,  there  are  a  great  many  places  W'here  gutta-percha  seems  to 
satisfy  more  of  the  requirements  than  any  other  material.  There  are 
places,  however,  where  its  insertion  represents  almost  anything  but 
cleanliness.  IMany  have  a  misconception  regarding  the  impermeability 
of  gutta-percha,  and  as  a  result  are  reluctant  to  substitute  other 
materials  when  it  can  as  well  be  done. 

Dr.  Black^  says:  "The  trial  that  has  been  made  of  gutta-percha  for 
the  exclusion  of  moisture  for  long  periods  of  time  from  ocean  cables 
has  shown  its  absolute  impermeability."  The  fact  that  gutta-percha, 
used  as  a  cover  for  ocean  cables,  is  almost  impervious,  is  true,  but  it 
is  to  be  regretted  that  this  statement  w-as  not  qualified  somewhat, 
because  as  it  stands  the  average  person  would  take  it  that  gutta-percha 
was  likewise  impervious  in  the  mouth. 

Attention  has  already  been  called  to  the  fact  that  gutta-percha  did 
not  combine  perceptibly  with  the  oxygen  of  water,  but  that  it  did 
with  the  oxygen  of  the  air  in  the  presence  of  light.  Under  the  latter 
conditions  gutta-percha  undergoes  rapid  decay,  and  gives  off  an  acrid 
odor.  Kirk  has  called  attention  to  the  action  of  sulphids  upon  gutta- 
percha. Thus,  w^hile  gutta-percha  is  impervious  when  inserted,  it 
undergoes  decay  from  at  least  two  causes.  Of  course  it  will  remain 
in  the  mouth  for  a  considerable  length  of  time  before  the  decay  be- 
comes very  perceptible,  but  fillings  of  long  standing  will  show  consid- 
erable change. 

Gutta-percha  is  still  a  very  useful  material,  but  it  should  not  be 

1  Operative  Dentistry,  vol.  ii,  p.  362. 


;JU  PLASTICS 

allowed  to  remain  exposed  to  the  oral  fluids  for  any  ^reat  length  of 
time.  It  may  be  used  to  set  almost  all  kinds  of  erowns  on  roots 
whieh  have  been  prej)ared  for  their  reeeption,  but  should  be  allowed 
to  remain  for  a  eonij)arati\ely  short  time  only.  Often  an  operation 
may  be  nearly  complete,  but  the  operator  may  wish  to  do  something 
more  Ix'fore  a  crown  is  placed  j)ernian('nt]y.  In  such  cases  a  little 
gutta-percha  which  has  been  made  plastic  by  heat  may  serxe  to  retain 
a  crown. 

The  same  is  true  regarding  its  use  for  fillings.  In  an  extensive  inlay 
practice  gutta-percha  is  almost  indispensable  as  a  temi)orary  stop- 
ping from  the  time  the  cavity  is  prepared  until  the  inlay  is  ready  to 
be  set.  It  is  usually  best  not  to  allow  much  time  to  elapse  between 
the  preparation  of  the  cavity  and  the  setting  of  the  inlay,  but  in  an 
extensive  practice  occasions  continually  arise  in  which  this  is  necessary. 
Gutta-percha  may  be  used  for  sealing  in  treatments  in  the  teeth  when 
the  cavity  is  sufficiently  large  to  permit  of  its  adaptation  without 
compression  of  the  pulp,  or  where  the  stress  of  mastication  will  not 
dislodge  it.  Dr.  Black^  states  that  "  It  should  be  the  only  material 
used  for  sealing  in  dressings  and  for  the  temporary  stoppings  in  con- 
nection with  treatments."  As  he  says,  gutta-percha  is  a  trying  material 
to  handle  until  the  technique  of  its  manipulation  has  been  mastered, 
but  it  is  difficult  to  understand  why  he  should  declare  that  it  is  the 
only  material  which  should  })e  used  for  sealing  in  dressings,  etc.,  when 
it  is  generally  conceded  that  the  basic  zinc  phosphates  fulfil  many 
requirements  better  than  gutta-percha.  For  example,  suppose  an  acci- 
dental exposure  is  made  in  the  preparation  of  a  ca\'ity  of  a  young 
patient  where  the  pulp  is  near  the  surface,  or  suppose  that  the  ex- 
posure has  been  made  by  caries  and  the  pulp  is  in  a  highly  inflamed 
condition.  In  either  case  the  medicinal  agent  would  probably  be 
mixed  with  one  of  the  nicely  prepared  oxids  as  a  carrying  agent  and 
gently  placed  over  the  exposure. 

As  a  sealing  for  the  cavity,  shallow  as  most  are,  nothing  would 
seem  to  meet  the  requirements  as  well  as  one  of  the  adhesive  basic 
zinc  phosphates,  which  could  be  applied  without  perceptible  pressure. 
There  are  many  cavities  which  present  a  different  problem.  They  may 
be  deep  and  easy  of  access.  In  such  cases  gutta-percha  would  be 
preferable  to  any  other  material. 

One  of  the  first  considerations  is  that  the  surfaces  to  which  gutta- 
percha is  applied  should  be  dry  and  free  from  greasy  materials.  This 
may  be  accomplished  by  the  adjustment  of  the  rubljcr  dam  or  by  the 
use  of  rolls  and  the  aid  of  an  assistant,  according  to  the  case  treated. 
If  the  gutta-percha  is  to  be  inserted  into  a  cavity  the  walls  should 
be  parallel  or  even  have  slight  retaining  points,  although  in  most  cases 

^Operative  Dentistry,  vol.  ii,  p.  '.iCA. 


GCrTA-I'ERCIIA 

Fig.  314 


315 


Thermoscopic  heater  for  gutta-percha. 
Fig.  31.5 


Flagg's  gutta-percha  softener  and  tool  heater. 


316 


PLASTICS 


the  cavity  formation  may  be  varied  somewhat  from  tliat  for  gold  or 
amalgam. 

When  the  ca\ity  has  been  prei)ared  for  the  filling  it  is  often  found 
advantageous  to  moisten   the    walls   with   eucalyptol  or  cajupnt  oil. 


Fui.  310 


Eleotro-Dental  IManufaoturing  Co. 
Trimmer  for  gutta-percha  heated  by  electricity. 


This  will  soften  the  gutta-percha  somewhat  and  add  to  its  adhesive- 
ness.    The  gutta-percha  should  then  be  made  plastic  b^-  passing  it 


GUTTA-PERCHA 


317 


over  tlie  flame  or  by  placiiic:  it  upon  one  of  the  specially  designed 
heaters.  It  is  often  convenient  to  use  the  different  varieties  of  gold 
annealers  for  tliis  })urpose.  The  heater  most  commonly  used  is  made 
of  steatite,  and  is  shown  in  Fig.  314.  The  heat-retaining  j)roperties  of 
soapstone,  together  with  its  desirable  surface,  make  it  as  good  a  heater 
as  any  yet  designed.  After  the  gutta-percha  has  been  softened  it  may 
be  rolled  into  a  single  piece  of  a  shape  convenient  for  insertion,  and 
packed  in  place  with  cool  instruments.  It  may  also  be  inserted 
gradually  b\'  adding  piece  after  piece  to  the  walls  of  the  cavity  and 
the  already  inserted  gutta-percha.  This  method  is  usually  better  if 
there  is  not  easy  access  or  if  there  is  danger  of  compressing  the  pulp 

Fig.  317 


Hot  air  syringe. 


or  forcing  medicinal  agents  through  the  apical  foramen  in  devitalized 
teeth.  After  the  cavity  is  filled  it  should  be  trimmed  to  shape  with 
the  ordinary  plastic  instruments  by  warming  them  to  a  point  where 
they  will  cut  through  the  gutta-percha  without  tending  to  draw  it 
from  the  cavity.  The  instruments  should  be  heated  gently  in  the 
flame  or  in  one  of  the  heaters,  as  shown  in  Fig.  315.  ScA'eral  instru- 
ments which  are  heated  by  the  electric  current  have  been  designed  for 
trimming  gutta-percha  (Fig.  316).  They  are  very  useful  for  some 
operations,  but,  as  a  general  rule,  a  little  more  clumsy  than  the  regular 
plastic  instruments. 

For  finishing  some  gutta-percha  fillings,  where  it  is  not  necessary  to 


318 


PLASTICS 


direct  the  Mast  of  hot  air  ajraiiist  the  soft  tissues,  tlie  eh'ctric  hot  air 
syriiiijje  (Fig.  'A\7)  is  ven-  useful.  It  may  \w  used  in  heatinj;  crowns 
whicli  have  been  set  temporarily  with  fjutta-penlia.  With  this  instru- 
ment a  blast  of  hot  air  may  he  directed  a<,'aiiist  a  {)()rcelain  crown, 
havini;  a  metal  post,  until  it  can  be  easily  removed.  When  the  hot 
air  syrinj2;e  is  used  to  soften  the  gutta-percha  only  very  sharj)  instru- 
ments should  be  used  to  trim  off  the  excess,  or  the  mass  will  l)e  mo\-ed 
in  the  cavity.  In  general,  gutta-percha  should  not  be  warmed  after 
being  inserted  into  the  cavity,  but  should  be  chilled  and  trimmed  with 
warm,  sharp  instruments.  Gutta-percha  ma>-  be  trimmed  into  shape 
with  the  ordinary  plastic  instruments  by  warming  them.  It  is  better, 
however,  to  use  more  of  the  sharp-edged  instruments,  such  as  car\ers 
and  excavators.  Heat  may  also  be  conveyed  to  large  masses  of  gutta- 
percha, especially  in  removing  crowns  set  with  this  material,  by  heating 
a  larger  burnisher  and  placing  it  upon  the  mass  of  gutta-percha.  It  is 
still  i)etter  to  place  a  good-sized  piece  of  copper  upon  an  instrument 
handle  (Fig.  31S). 

F'or  the  use  of  gutta-percha  as  a  root  canal  filling  see  Chapter  XIV. 


Fig.  318 


Gutta-percha  with  Other  Materials.  —  Temporary  Stopping.  —  This 
material  ditt'ers  from  ordinary  gutta-percha  chiefly  in  its  working 
qualities.  It  is  prepared  from  both  white  and  ])ink  gutta-percha  by 
the  addition  of  some  of  the  gums  or  waxes,  together  with  other  materials, 
such  as  certain  sulphates,  carbonates,  or  oxids. 

It  is  also  made  without  the  gums  or  waxes.  It  may  be  i)repared 
so  that  it  exhibits  considerable  adhesiveness  by  the  addition  of 
Burgundy  pitch.  These  preparations  are  designed  for  a  variety  of 
purposes;  their  principal  use  is  the  stopping  of  excavated  cavities  for 
a  short  time. 

As  the  name  implies,  they  are  intended  for  work  more  temporary 
in  nature  than  that  which  would  require  gutta-percha.      As  a  result 


TIN  AM)  ITS  COM lU NATIONS  319 

of  their  use  for  the  most  temporary  oi)erations,  many  of  the  qualities 
of  other  phisties  have  been  given  to  this  material  by  the  addition  of 
some  of  the  above-named  materials.  Many  of  these  preparations 
remain  quite  hard  in  tlie  mouth,  althouojh  some  are  less  resistant  than 
gutta-percha,  and  more  plastic  in  every  way.  The  most  conspicuous 
differences  between  them  and  gutta-percha  is  that  they  are  generally 
softened  with  lower  lieat  and  have  little  or  none  of  the  toughness  and 
stringiness  so  prominent  in  gutta-percha.  Their  manipulation  is  similar 
to  that  of  gutta-percha. 

Gutta-percha  and  Gum  Shellac. — Gutta-percha  may  be  mixed  with 
gum  shellac  to  make  a  stiff  and  yet  tough  material,  for  use  largely  as  a 
base-plate.  It  may  be  used,  however,  for  a  variety  of  purposes  where 
other  forms  of  gutta-percha  would  scarcely  be  rigid  enough. 

Gutta-percha  with  Medicinal  Agents. — Such  substances  as  oxid  of 
copper,  finely  divided  tin,  sih'er  nitrate,  eucalyptol,  creosote,  etc.,  are 
often  incorporated  with  gutta-percha.  It  is  claimed  by  the  makers 
of  some  of  the  gutta  points  supplied  for  filling  root  canals  that  the 
process  of  refining  the  crude  gutta-percha  removes  a  natural  oil  which 
should  be  supplied  before  the  points  are  suitable  for  use.  The  addition 
of  some  of  the  oils  in  such  cases  not  only  supplies  what  it  is  asserted 
to  have  been  removed,  but  for  a  time  makes  the  points  more  or  less 
antiseptic. 

The  other  substances  mentioned  are  less  frequently  added  to  gutta- 
percha. The  salts  of  copper  and  finely  divided  tin  can  be  advanta- 
geously incorporated  when  it  seems  imperative  to  leave  gutta-percha 
in  the  mouth  exposed  to  the  saliva  for  some  time.  The  use  of  gutta- 
percha with  either  of  these  materials  is  limited  to  remote  parts  of  the 
mouth  on  account  of  their  color.  The  manipulations  of  these  mixtures 
is  similar  to  that  of  gutta-percha  alone.  When  these  two  materials, 
or  other  similar  substances,  are  combined  with  gutta-percha,  the  result- 
ing product  is  not  unlike  it,  but  some  of  the  properties  of  the  combined 
substance  are  added. 

TIN  AND  ITS  COMBINATIONS 

Another  material  which  hardly  belongs  under  the  head  of  plastics 
is  tin.  It  possesses  some  plastic  properties,  however,  which  make  its 
brief  consideration  in  this  chapter  admissible.  Tin  as  used  by  dent- 
ists is  a  white  metal  with  a  brilliant  luster.  It  is  quite  malleable, 
although  less  so  than  gold.  It  is  not  very  tenacious,  comparing  with 
gold  in  the  ratio  of  two  to  seven.  Its  melting  point  is  very  low,  and 
its  annealing  point  likewise  low,  annealing  usually  being  accomplished  by 
keeping  the  tin  under  boiling  water  for  five  or  ten  minutes,  and  allowing 
it  to  cool  there.  Like  gold,  it  is  free  from  change  in  volume  due  to  chemi- 
cal change,  its  only  change  in  volume  appearing  with  thermal  variations. 


320  PLASTICS 

It  is  ail  inferior  conductor  of  heat  and  electricity.  In  an  alloyed  or 
finely  divided  state  it  tarnishes  readily,  althon<,^li  when  used  as  a  coating 
for  articles  made  of  iron,  etc.,  or  in  ingot  form,  it  remains  of  a  compara- 
tively l)right  color. 

Like  gold,  it  can  be  welded  in  the  cold  state.  This  latter  property  is 
still  (luestioned  hy  many  who  hold  that  its  use  in  dentistry  as  a  fill- 
ing material  is  made  possible  through  a  mechanical  entanglement  of 
the  pieces  of  tin  used.  This  supposition,  however,  seems  to  be  based 
upon  obscrxations  made  on  tin  in  the  form  of  foil.  If  the  more 
recently  introduced  tin  shavings  are  used,  while  freshly  cut,  the  cohe- 
sive property  ai)pears  in  an  unmistakable  manner.  This  cohesive 
proi)erty  seems  to  be  lost  somewhat  with  the  rolling  and  beating 
necessary  to  produce  the  tin  in  sheet  form.  Like  gold  foil,  its  cohesive- 
ness  is  lost,  either  by  a  union  with  or  a  condensation  upon  its  surface 
of  substances  often  present  in  the  atmosphere,  and  this  cohesiveness 
caimot  be  restored  by  heating. 

It  may  be  seen  that  tin  resembles  gold  more  closely  in  many  of  its 
properties  than  it  does  the  other  filling  materials.  Probably  those  who 
have  been  most  successful  with  it  have  treated  it  in  much  the  same 
manner  as  non-cohesive  gold.  Its  use  alone  or  in  combination  with 
gold  foil  seems  to  be  indicated  in  places  where  a  permanent  operation 
is  desired,  but  which  cannot  be  well  done  with  gold  foil  because  of  lack 
of  access.  In  very  inaccessible  places  the  plastic  nature  of  tin  usually 
permits  of  a  much  better  adaptation  to  the  margins  and  walls  of  the 
tooth  than  gold  foil.  Tin  is  generally  selected  for  cases  in  which  gold 
foil  could  be  employed  were  it  not  for  the  difficulty  of  access  and  the 
fact  that  better  results  are  obtained  when  some  tin  is  used  in  connec- 
tion with  the  gold.  Some,  however,  use  it  in  ca^•ities  of  easy  access 
because  they  believe  it  has  great  preservative  qualities.  Those  w^ho 
believe  most  strongly  in  its  preservative  qualities  often  practise  little 
or  no  extension  to  areas  of  relative  immunity,  and  yet  their  success 
with  tin  is  as  great  as  that  of  those  who  do.  Such  successes  may  be 
attributed  partly  to  the  plastic  "nature  of  tin  and  its  consequent  ready 
adaptation,  but  the  consensus  of  opinion  would  probably  fa\'or  the 
theory  that  the  tin  possesses  some  inherent  preservative  qualities. 

There  are  few  who  do  not  feel  that  tin  has  some  property,  peculiar 
to  itself,  of  inhibiting  caries,  and  yet  there  seems  to  be  no  definite 
understanding  of  the  process. 

Dr.  W.  T.  Miller^  has  stated  that  tin  is  neither  antiseptic  nor  thera- 
peutic in  acticm;  Marshall,-  that  it  is  decidedly  antiseptic  when  oxidized; 
and  Ambler,'^  that  "the  filling  itself  will  prevent  caries,  but  the  oxid  of 
tin  formed  in  the  mouth  affords  an  additional  barrier."  Thus,  it 
may  be  seen  that  there  are  a  variety  of  views  as  to  how  tin  saves  teeth. 

1  Dental  Cosmos,  vol.  xxxii,  p.  714.  *  Operative  Dentistry,  p.  286. 

'  Tin  Foil  and  its  Combinations,  p.  42. 


TIN  AND  ITS  COMBINATIONS  321 

Many  have  observed  that  not  all  tin  filhiigs  were  oxiflized,  Neitlier 
had  any  other  salt  formed  to  any  appreeiahle  extent,  and  yet  the  tooth 
tissue  was  proteeted  equally  well.  Probably  most  tin  fillings  which 
have  not  turned  black  after  some  time  in  the  mouth  have  been  located 
where  there  was  abrasion  of  its  surface,  although  there  seems  to  be 
some  difference  in  the  action  of  the  oral  fluids  upon  this  material. 

The  preservative  qualities  of  tin  claimed  by  so  many  seem  not 
entirely  dependent  u})on  either  the  antiseptic  action  of  tin  or  its  salts, 
but  also  upon  a  change  produced  in  the  tooth  tissue  which  is  decidedly 
antagonistic  to  the  progress  of  caries.  Those  who  have  examined  cavi- 
ties which  have  had  tin  fillings  for  some  time  almost  invariably 
observed  a  tissue  change  which  in  the  case  of  other  filling  materials 
occurred  only  when  alloys  containing  large  percentages  of  copper  were 
used. 

Tin  may  be  used  either  alone  or  with  gold.  Many  operators  employ 
it  in  the  form  of  foil  or  shavings  to  fill  the  cervical  portion  of  proximate 
cavities  in  remote  parts  of  the  mouth  or  at  least  obscured  from  view. 
In  such  cases  it  is  usually  manipulated  like  non-cohesive  gold,  and  is 
used  as  a  base  for  the  remainder  of  the  filling,  which  may  be  either 
non-cohesive  or  cohesive  gold.  It  possesses  too  much  flow  for  a  suc- 
cessful base  for  gold  fillings  when  much  force  is  to  be  applied  to  the 
filling,  and  should  be  used  in  this  manner  only  when  the  force  of  occlu- 
sion is  distributed  over  nearly  all  the  teeth. 

Tin  foil  may  be  used  with  gold  in  the  form  of  a  "tin-gold,"  a  sheet 
of  tin  and  a  sheet  of  gold  being  rolled  together.  This  combination 
may  vary,  some  operators  preferring  slightly  more  of  one  metal  than 
the  other.  It  may  be  folded  or  crimped  to  make  a  material  which 
works  in  slightly  different  fashion,  but  in  either  case  the  tin  and  gold 
are  inserted  together. 

"Tin-gold"  is  usually  made  from  the  thinner  tin  foils  and  non- 
cohesive  gold  foil.  No.  4  being  very  good  for  both.  It  is  inserted  in 
the  same  manner  as  non-cohesive  gold,  and  when  finished  possesses 
many  of  the  properties  of  that  material,  but  is  more  plastic,  a  poorer 
conductor,  different  in  color,  and  somewhat  weaker  at  the  time  of 
insertion.  Many  have  observed  that  "tin-gold"  fillings  after  some 
time  have  changed  in  character.  Instead  of  being  relatively  malle- 
able as  when  inserted,  the  mass  seems  to  form  a  typical  gold-tin 
alloy  by  becoming  harder  and  more  brittle.  There  is  good  reason 
to  believe  that  this  is  what  has  taken  place. 

Recent  investigations  tend  to  show  that  many  metals  will  alloy  with 
other  metals,  if  they  are  pure,  when  brought  into  intimate  contact  in 
the  absence  of  heat.  As  long  ago  as  1878,  Professor  Spring,  of  Liege, 
made  studies  of  the  different  methods  of  producing  alloys  by  com- 
pressing the  constituent  metals,  and  was  able  to  produce  certain 
alloys  in  the  absence  of  heat  that  possessed  physical  properties  quite 
21 


322  PLASTICS 

analogous  to  those  })ro(luct'(l  by  heat.  Sj)nnjj:'s  stii(hes  ha\  e  since  l)een 
extended  and  liis  observations  have  been  confirmed  by  others  until 
these  phenomena  are  looked  upon  as  comparatively  ordinary  occur- 
rences. 

Tin-gold  may  be  used  in  places  where  either  tin  or  non-cohesive  gold 
are  used.  The  insertion  and  finishing  of  the  filling  are  accomplished 
in  the  same  manner  as  non-cohesive  gold  or  tin. 

Some  operators  have  used  tin  foil  in  combination  with  amalgam  with 
a  degree  of  success,  but  it  has  disadvantages  when  used  in  this  manner 
that  do  not  occur  when  it  is  employed  with  other  materials.  It  will  be 
recalled  that  change  of  volume  in  filling  materials  is  either  physical, 
due  to  thermal  variations,  or  chemical,  due  to  the  union  of  two  or 
more  substances.  Tin  alone  is  subject  to  physical  change  in  volume 
only,  and  this  is  probably  also  largely  true  W'hen  it  is  used  as  the  base 
of  a  gold  filling.  Likewise  probably  little  chemical  change  in  volume 
occurs  during  the  early  stages  of  a  tin-gold  filling,  although  it  may  be 
considerable  during  the  later  stages. 

When  amalgam  is  used  as  a  covering  for  tin  fillings,  as  is  done  by 
some  operators,  a  contraction  of  the  whole  mass  is  likely  to  result  if 
the  amalgam  has  been  made  from  a  low  percentage  silver  alloy,  but  not 
so  much  so  if  a  rapid  setting  alloy  has  been  used.  It  would  seem  that 
there  is  little  or  no  occasion  for  the  use  of  amalgam  with  tin,  although 
some  regard  it  a  useful  combination.  When  amalgam  is  used  wnth  tin 
it  is  inserted  as  a  covering  for  it  so  that  the  surface  of  the  filling  will 
be  harder  than  it  would  be  if  made  entirely  of  tin.  Such  operations, 
however,  are  confined  to  remote  parts  of  the  mouth. 

UNINGS  FOR  CAVITIES. 

In  the  practice  of  dentistry  it  often  becomes  necessary  to  line  the 
walls  of  a  cavity  or  to  coat  the  surface  of  teeth  with  substances  which 
are  poor  conductors  or  will  prevent  the  irritant  action  of  certain  filling 
materials,  such  as  some  of  the  cements.  Of  the  materials  a\ailable  for 
this  purpose  the  various  varnishes  are  most  used.  They  are  solutions 
of  gums  and  resins  in  alcohol,  chloroform,  and  ether,  which  can  be 
applied  in  a  film  as  a  protective  to  the  walls  of  cavities  or  surfaces 
of  teeth. 

Sandarac  in  alcohol,  and  hard  Canada  balsam,  copal,  or  damar  in 
ether  are  among  the  more  common  of  these  materials.^  The  prepara- 
tion known  as  Kristaline,  a  solution  of  trinitrocellulose  in  anhydrous 
amyl  acetate  (Kirk),  is  also  used.  Virgin  rubber  or  gutta-percha  dis- 
solved in  chloroform  may  be  used  in  the  same  manner;  in  most  cases 

'  For  some  formula;  of  these  varnishes  the  reader  is  referred  to  Dr.  Prinz's  Dental 
P'ormulary. 


LIXIXGS  FOR  CAVITIES  323 

tlio  latter  two  are  less  desirable,  as  they  are  less  a(lhesi^•e.  Silver 
nitrate  has  been  extensively  used  as  a  lining  for  cavities,  especially  in 
cases  of  carious  tissue  whose  removal  was  impractical.  It  must  not 
be  regarded  as  a  non-conductor  in  the  sense  that  the  varnishes  are, 
however,  because  it  is  reduced  to  metallic  silver  when  brought  in  con- 
tact with  organic  substances,  hence  the  dark  color.  These  different 
linings,  especially  the  gums  and  resins,  are  of  great  value  in  preventing 
galvanic  disturbances  and  rapid  conducti\'ity  of  thermal  impression 
produced  by  amalgam.  They  are  also  useful  under  gold  fillings  and  the 
full  and  partial  caps  often  placed  upon  teeth.  They  are  also  useful  in 
preventing  the  irritant  action  of  both  the  basic  zinc  phosphates  and 
the  silicate  cements.  In  the  earlier  stages  of  the  setting  of  either 
class  free  acid  is  likely  to  form,  w'hile  during  the  stages  of  disintegra- 
tion acid  salts  are  apt  to  occur  in  contact  with  the  dentinal  walls  if 
a  lining  has  not  been  used. 

Formerly  some  of  these  linings  were  used  to  prevent  the  discoloration 
of  tooth  tissue  by  amalgam,  but  this  is  not  necessary  with  the  more 
recent  ones.  It  is,  however,  a  good  precaution  to  take  if  copper  amal- 
gam is  used.  These  linings  may  be  applied  to  the  walls  of  the  cavity 
or  surfaces  of  a  tooth  with  the  ordinary  pliers  and  a  bit  of  cotton,  or 
directly  with  any  small  instrument.  Before  their  application,  the 
surface  should  have  had  the  regular  treatment  given  to  ca^'ities  pre- 
paratory to  filling  and  should  have  been  wiped  with  a  solution  of 
sodium  carbonate  to  remove  traces  of  greasy  substances.  After  the 
lining  has  been  applied  it  should  be  allowed  to  stand  until  the  greater 
part  of  the  volatile  portion  has  disappeared  and  the  lining  is  quite  hard. 


CHAPTEK    XII 

COMBINATION  FILLINGS 

By  MARCUS  L.  WARD,  D.D..Sc. 

A  CAREFUL  study  of  tlio  materials  available  for  use  iu  filHun;  teeth  shows 
that  no  one  of  them  quite  meets  all  the  demands  of  modern  dentistry. 
Some  possess  artistic  qualities  but  lack  strengtli.  Others  that  possess 
the  best  strength  are  the  farthest  from  nature  in  eolor.  This  is  also  (rue 
in  regard  to  their  destruetibilitj  in  the  oral  media.  Some  are  wholly  in- 
soluble, while  others  are  quite  soluble  in  saliva,  products  of  fermentation 
and  certain  food  substances.  Some  materials  are  excellent  conductors, 
while  others  are  very  poor  ones.  One  or  two  are  liable  to  considerable 
alteration  in  volume  due  to  chemical  change,  while  others  are  only  sub- 
ject to  change  in  volume  due  to  thermal  changes,  one  or  two  possessing 
a  very  small  co-efficient  of  contraction  and  expansion. 

The  alloys  and  cements  now  in  use  represent  attempts  to  combine  the 
desirable  (|ualities  of  several  materials  in  one  product.  These  products 
often  show  that  a  material  with  only  one  desirable  (juality  and  several 
undesirable  qualities  may  be  introduced  as  a  filling  provided  the  former 
is  pronounced.  Even  the  most  skilful  makers  have  not  yet  succeeded  in 
producing  a  material  even  approximately  suitable  for  use  alone  in  all  cases. 

A  filling  material  should  be  indestructible  in  the  oral  media,  should 
approximate  the  color  of  the  teeth,  be  free  from  contraction  and  ex- 
pansion after  being  made  into  fillings,  should  resist  attrition  and  the 
force  of  mastication,  be  a  poor  conductor,  easily  manipulated,  and  quite 
adaptable  to  the  walls  of  a  cavity.  Thus  the  recpiirements  for  a  dental 
filling  material  are  enormous  and  out  of  proportion  to  the  demands 
made  upon  most  materials  in  use  in  allied  sciences. 

There  is  a  constant  desire  that  a  filling  material  should  possess  one  or 
more  additional  qualities  and  an  increasing  tendency  to  combine  two 
or  more  materials  to  obtain  the  quality  sought.  The  zinc  phosphate 
cements  have  many  excellent  qualities  and  are  almost  invaluable.  Their 
one  good  cjuality  above  all  others  is  the  property  of  adhesiveness,  a 
(|uality  sought  but  practically  absent  in  all  other  filling  materials.  They 
are  generally  manipulated  with  ease,  their  color  is  good,  and  under 
proper  handling  they  are  relatively  free  from  contraction  and  expansion, 
but  they  are  not  indestructible  in  the  mouth.  Gold  has  many  excel- 
lent qualities,  being  strong,  wholly  indestructible  in  the  mouth,  and  free 
from  contraction  or  expansion  caused  by  chemical  changes.  It  is  adapt- 
(324) 


COMBINATION  FILLINGS  325 

able  to  many  cases,  but  its  color  is  poor,  its  insertion  is  tedious  to  both 
operator  and  patient,  and  it  is  an  excellent  conductor.  Amalgam  may 
be  similarly  criticised.  While  it  may  be  inserted  in  places  inaccessible  to 
gold  and  last  longer  than  most  cement  fillings,  as  a  whole  its  qualities 
are  poor  when  compared  with  the  ideal  standard  for  filling  materials.  It 
is  almost  but  not  entirely  indestructible  in  the  mouth.  Its  strength  is 
indefinite.  It  is  subject  to  chemical  change  in  volume  after  insertion. 
Its  color  is  poor  and  it  is  a  good  conductor.  Certain  of  these  objection- 
able qualities  are  very  conspicuous  when  these  fillings  are  used  alone  or 
in  places  where  another  filling  material  is  indicated.  For  example,  the 
examination  of  a  large  number  of  amalgam  fillings  in  occlusal  cavities 
will  show  more  imperfect  edges  than  in  the  case  of  fillings  of  a  similar 
shape  located  on  the  buccal  or  proximal  surface.  The  difference  be- 
tween these  classes  of  fillings  is  due  to  the  fact  that  one  class  is  sub- 
jected to  stress  and  the  other  is  not. 

Even  when  strongest,  amalgam  is  relatively  brittle  and  the  change  in 
volume  is  usually  sufficient  to  cause  fracture  of  the  amalgam  when  in 
the  course  of  time  it  is  no  longer  supported  by  the  cavity  margins  and 
stress  is  applied.  Similarly  located  gold  fillings  do  not  show  the  differ- 
ences noted  with  amalgam,  as  gold  is  not  britde,  and  also  remains  more 
constant  in  volume.  When  placed  against  a  margin  it  does  not  rise  up 
above  it  nor  shrink  below  it,  as  do  most  amalgam  fillings.  The  deduc- 
tion seems  to  be  that  of  the  two  materials,  gold  is  much  better  for  loca- 
tions where  stress  is  applied. 

If  a  number  of  proximal  gold  or  amalgam  fillings  be  examined,  the 
metal  is  usually  found  to  show  through  the  enamel,  oftentimes  conspicu- 
ously, on  the  buccal  or  labial  side.  This  is  particularly  true  when  the 
cavities  are  quite  deep.  In  such  an  examination,  hqwever,  a  few  fillings 
are  usually  found  near  the  surface  which  do  not  appear  as  dark  as  some 
others.  Closer  examination  shows  that  some  of  the  light-colored  cements 
have  been  placed  between  the  filling  and  the  wall  of  the  cavity.  There  can 
be  litde  doubt  but  that  the  combination  of  the  two  filling  materials  has 
brought  about  a  better  result  than  one  material  could  do.  Thus,  the 
adhesive  quality  of  the  cement  may  be  utilized  to  make  metal  fillings 
more  sighdy  as  well  as  to  strengthen  the  frail  walls  of  such  cavities. 
For  this  reason  it  is  often  desirable  to  combine  in  one  filling  two  or 
more  materials.  It  is  the  careful  selection  of  filling  materials  and  the 
ingenuity  in  combining  them  that  saves  the  most  teeth. 

Some  seem  to  adhere  to  the  idea  that  a  material  adapted  for  one  place 
is  equally  adapted  for  others,  and  that  combination  fillings  are  resorted 
to  because  they  are  easier  made  than  fillings  of  one  material.  Such  is 
not  true.  If  an  operator  gives  his  patients  his  best  services  he  will 
make  the  same  effort  to  combine  the  qualities  of  different  filling  materials 
that  the  makers  of  these  products  make  in  combining  the  qualities  of 
different  substances  for  a  single  filling  material. 


326  COMBINATION  FILLINGS 

It  may  be  said  truthfully  that  an  operator's  services  may  be  measured 
only  by  his  ingenuity  in  carrying  to  completion  the  plan  adopted  by 
the  makers  of  fillinif  materials.  In  this  chapter  only  the  mechanical 
operation  of  insertin*,'  the  filling  will  be  considered.  All  operations 
upon  the  pulp  and  root  canals  will  be  eliminated  and  the  teeth  will  be 
considered  ready  to  receive  fillings.  Not  all  combination  fillings  will  be 
described.  Only  those  most  important  will  be  considered,  leaving 
those  of  lesser  importance  to  the  ingenuity  of  the  operator. 


CEMENT  (ZINC  PHOSPHATE)   AND  AMALGAM 

This  combination  is  one  of  the  oldest  and  has  been  most  serviceable 
in  saving  teeth  that  would  otherwise  have  been  crowned  or  lost. 
Originally  the  combination  was  employed  in  cavities  where  the  interior 
of  the  cavity  was  much  larger  than  the  orifice.  Such  cavities  are  most 
frequent  on  the  occlusal  and  proximal  surfaces  of  the  teeth.  Many 
cases  are  seen  where  little  but  the  enamel  is  left,  which,  when  supported 
by  an  adhesive  material,  will  withstand  the  ordinary  stress  of  mastication. 

Fig.  321  shows  an  occlusal  cavity  of  this  kind,  which  consists  princi- 
pally of  a  shell  of  enamel.  To  open  such  a  cavity  until  there  were  no 
undercuts  would  obliterate  the  occlusal  surface,  while  to  fill  it  with  a 
non-adhesive  material  would  result  in  the  breaking  down  of  the  over- 
hanging ledges  of  enamel  under  the  ordinary  stress  of  mastication.  It 
may  be  recalled  in  this  connection  that  enamel  is  much  weaker  than 
dentin,  that  it  requires  a  piece  of  dentin  approximately  yw  inch  thick  to 
sustain  the  force  of  mastication  in  the  molar  region,  and  that  no  strength 
is  added  to  the  tooth  by  metallic  fillings,  the  inlays  excepted.  Hence, 
filling  such  cavities  with  amalgam  or  gold  alone  is  folly. 

The  combination  of  an  adhesive  material  with  a  metal,  however,  gives 
an  operation  which  often  withstands  the  work  of  mastication  for  years. 
There  are  two  methods  for  combining  cement  and  amalgam.  The  first 
consists,  in  occlusal  cavities,  of  filling  the  entire  cavity  with  cement 
mixed  to  a  putty-like  consistency  and  allowing  it  to  harden  so  that  it 
may  be  cut  with  sharp  instruments  without  moving  its  body  and  then 
cutting  into  it,  a  cavity  with  parallel  walls  of  the  size  of  the  orifice  of 
the  cavity.  Such  a  filling  has  the  appearance  of  an  amalgam  filling,  but 
it  is  in  reality  a  cement  filling  with  a  veneer  of  amalgam,  which  protects 
the  cement  from  the  solvent  action  of  the  saliva  and  from  becoming 
abraded  by  attrition.  In  large  proximal  cavities  especially,  where  the 
pulp  has  been  removed,  a  similar  procedure  may  be  pursued  to  advan- 
tage. A  cavity  such  as  shown  in  Fig.  319  may  be  filled  with  cement  and 
made  to  appear  as  Fig.  320. 

As  may  be  seen,  the  part  of  the  cavity  left  to  be  filled  with  amalgam 
is  really  a  veneer  covering  the  proximal  and  occlusal   portion  of  the 


CEMENT  AND  AMALGAM 


327 


cavitv.  In  these  cases  the  eement  forms  a  support  for  the  frail  walls 
which  a  metallic  Hliinij;  could  not  supply.  Cement  must  not  be  used  in 
too  great  quantities  if  the  best  results  are  to  be  obtained. 

Amalgam  in  thin  layers  will  not  withstand  the  force  of  mastication 
unless  it  has  been  packed  into  the  cement  while  soft,  thus  uniting  the 
amalgam  to  the  cement.  This  constitutes  another  method  of  combining 
amalgam  and  cement  in  the  form  of  an  inlay,  and  is  known  as  an 
amalgam  inlay.  The  popularity  of  the  inlay  method  of  filling  teeth 
seems  responsible  for  the  wide  use  of  this  combination. 

In  large  occlusal  cavities  such  as  shown  in  Fig.  321,  the  cement  should 
be  mixed  to  a  consistency  suitable  for  setting  inlays  and  carried  to  the 
cavity  with  a  Spalding  loop  (Fig.  322)  or  other  suitable  instrument  and 
teased  over  the  entire  surface  of  the  cavity. 


Fig.  319 


Fig.  320 


Fig.  321 


Devitalized  molar  tooth  with 
cavity  outlined. 


Molar  tooth  devitalized 
with  cavity  outlined  and 
cement  in  place  to  be  covered 
with  amalgam  or  gold. 


Large  occlusal  cavity  par- 
tially filled  with  amalgaiTi 
and  soft  cement  showing  soft 
cement  oozing  out  of  cavity 
at  margins. 


Amalgam  which  has  been  previously  mixed  and  kept  moving  by  the 
assistant  so  that  it  will  not  become  too  stiff  is  now  packed  in  large 
pieces  in  the  bottom  of  the  cavity  from  the  centre  to  the  sides,  allowing 
the  excess  cement  to  flow  out  of  the  cavity  (Fig.  321).  Care  must  be 
exercised  not  to  leave  a  visible  layer  of  cement  between  the  amalgam 
and  cavity  margin,  or  the  cement  will  dissolve  out.  The  amalgam 
should  be  carefully  finished  to  the  edges  of  the  cavity,  so  as  to  cover 
the  cement  as  nearly  as  possible.  The  cement  is  usually  reduced  to  a 
very  thin  layer  by  this  method  of  insertion,  although  a  sufficient  amount 
remains  to  unite  the  cavity  wall  to  the  amalgam,  thus  supporting  the 
frail  walls  in  a  manner  impossible  with  amalgam  alone. 

In  filling  proximo-occlusal  cavities  which  have  frail  walls  the  same 
technique  may  be  pursued,  except  that  the  thin  cement  should  not  be 


328  COMBINATION  FILLINGS 

placed  along  the  border  of  the  cavity  next  to  the  matrix  and  tlie  amalgam 
should  be  packed  along  thi.s  border,  first  causing  the  excess  cement  to 
flow  out  of  the  occlusal  portion  of  the  cavity.  The  amalgam  and  cement 
method  has  been  used  with  advantage  in  highly  sensitive  cavities  where  a 
proper  retaining  form  could  not  be  obtained.  Fig.  320  shows  an  ap{)roxi- 
mal  cavity  which  might  be  filled  with  amalgam  and  soft  cement,  often 
giving  good  results.  Such  operations,  however,  are  not  always  the  best 
possible,  but  perhaj)s  the  best  under  the  circumstances.     The  so-called 

Fig.  322 


Spalding  loop  for  carrying  cement. 

amalgam  inlay  has  also  been  used  successfully  in  building  up  broken- 
down  molars  and  bicuspids.  There  is  a  tendency  to  use  soft  cement 
under  all  large  amalgam  fillings,  regardless  of  the  necessity  for  an 
adhesive  material  to  strengthen  the  tooth  or  to  retain  the  filling.  The 
lessened  conductivity  of  the  combined  cement  and  amalgam  seems  in 
many  ca.'^s  to  warrant  the  use  of  the  two  in  preference  to  amalgam 
alone,  while  in  other  cases  the  improvement  in  the  color  of  the  tooth  is 
quite  marked. 

CEMENT  AND  GOLD 

Cement  and  gold  may  be  used  in  posterior  cavities  in  much  the  same 
manner  as  has  been  described  for  amalgam,  (rold,  however,  cannot  be 
packed  into  soft  cement  in  the  same  manner  as  amalgam.  The  class 
of  cavities  selected  in  the  posterior  part  of  the  mouth  to  be  filled  with 
gold,  as  a  rule,  do  not  require  the  adhesive  material,  and  besides  it  is 
almost  impossible  to  pack  gold  into  soft  cement  anywhere  except  on  the 
floor  of  the  cavity.  Filling  occlusal  and  proximo-occlusal  cavities  par- 
tially full  of  cement  (Fig.  320)  and  allowing  it  to  harden  is  commonly 
practised,  since  it  is  comparatively  easily  done  and  the  filling  so  inserted 
has  the  same  advantages  with  gold  as  it  has  with  amalgam.  Cement 
inserted  in  this  manner  must  be  allowed  to  harden  sufficiently  to  resist 
the  impact  of  the  mallet  in  condensing  the  gold  without  being  disturbed, 
otherwise  the  gold  will  often  become  loose  after  the  operation  is  partially 
completed.  Some  operators  use  a  small  amount  of  rapid-setting  soft 
cement  in  the  base  of  all  cavities  to  be  filled  with  gold.  In  such  cases 
some  of  the  so-called  "  sponge"  golds  are  usually  employed  to  pack  a 
quantity  into  the  soft  cement,  after  which,  allowing  the  cement  to 
harden  somewhat,  more  of  the  "sponge"  gold  or  some  of  the  foil  golds 
may  be  built  upon  the  gold  which  has  been  packed  into  the  cement. 

Care  must  be  exercised  to  use  sufficient  gold  so  that  the  soft  cement 
will  not  ooze  through  the  gold,  thus  destroying  tiie  cohesiveness  of  its 


AMALGAM  AND  GOLD  329 

surface.  The  same  care  should  be  exercised  not  to  use  too  much  cement, 
but  only  enough  to  fasten  the  gold  to  the  surface  of  the  cavity.  This 
method  of  combining  gold  with  cement  will  be  found  useful  in  the 
anterior  teeth  and  the  bicuspids  where  a  dark  area  is  likely  to  be  pro- 
duced by  the  metal  underneath  thin  layers  of  the  tooth  structure.  If  a 
light-colored  cement  is  used,  the  effect  is  often  much  better  than  it  other- 
wise would  be.  Cases  of  hypersensitive  dentin  often  present  compli- 
cations which  make  it  necessary  to  resort  to  cement  for  anchorage.  It 
may  not  be  necessary  for  appearance,  nor  always  necessary  to  gain 
strength,  but  it  may  be  the  only  means  of  securing  anchorage.  This  is 
oftentimes  true  in  the  teeth  of  young  patients. 

Teeth  that  have  been  somewhat  discolored  may  often  be  made  much 
lighter  by  lining  the  cavity  with  a  light-colored  cement  before  inserting 
gold.  Cavities  in  central  incisors,  having  frail  enamel  walls  that  were 
in  the  past  frequently  filled  with  cement  and  gold,  and  would  still  be 
filled  to  advantage  that  way  if  gold  were  to  be  used,  would  at  the 
present  time  preferably  be  restored  by  most  operators  by  the  porcelain 
inlay.  In  fact,  the  whole  field  of  operative  dentistry  has  been  so 
changed  by  the  introduction  of  porcelain  and  gold  inlays  and  silicate 
cements  that  the  practice  of  filling  such  cavities  with  cement  and  gold, 
amalgam  and  gold,  or  cement,  amalgam,  and  gold,  has  become  almost 
obsolete. 

AMALGAM  AND  GOLD 

Amalgam  and  gold  have  been  used  to  advantage  in  many  places, 
principally,  however,  in  proximal  cavities  in  bicuspids  and  molars  which 
involve  more  or  less  of  the  occlusal  surface.  Before  the  advent  of  gold 
and  porcelain  inlays  and  silicate  cements,  gold  was  used  to  cover  amal- 
gam on  the  buccal  surfaces  of  the  bicuspids  and  molars  much  more 
than  now,  although  some  operators  still  adhere  to  this  method  in  prefer- 
ence to  the  more  recent  ones.  The  filling  of  mesio-approximal  cavities 
in  upper  bicuspids  and  molars  which  involve  considerable  of  the  buccal 
surface,  even  with  the  lighter-colored  amalgams,  is  regarded  as  especially 
poor  practice  by  most  operators,  since  there  are  a  variety  of  combina- 
tions which  may  be  used  to  prevent  the  exposure  to  view  of  the 
unsightly  amalgam.  Many  enthusiasts  hold  that  such  cavities  can  be 
filled  with  the  silicate  cements,  while  the  more  conservative  claim  that 
they  can  better  be  filled  with  amalgam  and  gold. 

Fig.  321  shows  a  cavity  which  in  most  cases  is  extremely  difficult  to 
fill  with  gold  foil  because  it  is  so  wide  at  the  cervical  portion  and 
extends  some  distance  below  the  gum  line.  It  is  equally  difficult  to 
keep  such  a  cavity  perfecdy  dry  during  the  insertion  and  finishing  of  a 
silicate  cement  and  these  fillings  are  of  litde  value  unless  they  are  kept 
free  from  moisture  during  the  first  few  hours  of  setting.    If  such  cavities 


330  COMBINATION   FILLINGS 

do  not  extend  too  far  laterally  it  is  often  better  to  cnt  them  open  to 
receive  either  a  jrold  or  porcelain  inlay,  but  in  many  of  them  caries  has 
proceeded  too  far  to  admit  of  either.  Such  cavities  can  be  filled  with 
amalgam  and  the  amalgam  allowed  to  harden,  after  which  the  portion 
exposed  to  view  may  be  cut  away  and  filled  with  gold. 

When  gold  and  amalgam  are  used  in  combination  it  often  becomes 
necessary  to  make  a  retaining  form  in  the  amalgam  for  anchoring  the 
gold.  There  is  no  union  between  the  two  after  the  amalgam  has  hard- 
ened, and  often  such  cavities  can  be  filled  only  by  gaining  a  reten- 
tion somewhat  remote  from  the  place  where  gold  is  to  be  placed,  thus 
requiring  the  retention  for  the  gold  to  be  placed  in  the  amalgam. 
Some  operators  use  amalgam  and  gold  to  fill  occlusal  cavities  similar 
to  the  one  shown  in  Fig.  321.  The  advantages  of  this  combination, 
however,  over  that  of  cement  and  gold  in  such  places  are  not  very 
apparent.  Many  in  the  past  have  considered  it  necessary  to  place 
cement  under  all  amalgam  fillings  which  were  to  have  gold  in  com- 
bination, in  order  to  increase  the  strength  and  to  diminish  the  amount 
of  discolored  tooth  tissue  from  the  amalgam. 

The  tendency  seems  to  be  to  use  cement  under  all  large  amalgam 
fillings  whether  gold  is  used  or  not,  that  there  shall  be  increased 
strength;  but  there  seems  little  or  no  thought  of  preventing  discoloration 
of  tooth  tissue,  as  with  proper  use  of  modern  alloys  this  is  extremely 
rare.  Gold  has  been  used  with  amalgam  by  packing  the  gold  into  the 
amalgam  while  soft,  but  the  operation  seems  to  be  about  obsolete. 
Recent  studies  of  amalgams  seem  to  make  it  clear  that  like  other  crys- 
tallizing bodies  they  should  not  be  disturbed  during  the  setting  process, 
more  than  is  necessary  when  placing  gold  over  soft  amalgam.  Special 
emphasis  has  been  placed  upon  using  steady  but  firm  pressure  in  pack- 
ing amalgam  and  allowing  it  to  lie  still  until  hardened. 


GUTTA-PERCHA  AND  CEMENT 

Gutta-percha  has  unquestionably  had  its  field  of  usefulness  lessened 
materially  within  the  last  few  years.  It  has  been  used  in  combination 
with  cement,  gold,  and  amalgam,  and  served  a  very  useful  purpose. 
The  demands  of  the  profession,  however,  for  better  hygienic  conditions 
in  the  mouth  has  practically  eliminated  it  except  for  the  most  temporary 
operations.  Gutta-percha  fillings  which  are  expected  to  remain  for 
months  are  fast  being  regarded  as  bad  practice,  regardless  of  whether 
the  gutta-percha  is  in  combination  with  other  materials  or  not.  The 
recent  demands  of  orthodontists  for  a  harder  material  with  a  well- 
restored  contour  for  proximal  cavities  has  also  served  to  lessen  the 
amount  of  gutta-percha  used. 

Gutta-percha  may  be  used  in  combination  with  cement  by  placing 


BASIC  ZIXC  PHOSPHATES  AND  SILICATE  CEMENTS       SiU 

it  at  the  cervical  tliinl  of  proximal  cavities  where  cement  is  often  dis- 
solved out  first,  hut  the  tendency  is  to  refrain  from  inserting  gutta- 
percha where  it  is  exposed  to  the  oral  fluids.  This  has  been  one  of 
the  methods  employed  to  meet  the  recjuirements  of  some  of  the  per- 
plexing operations  on  the  deciduous  teeth.  INIany  operators  adhere  to 
the  use  of  oxyphosphates  of  copper  for  all  operations  on  the  deciduous 
teeth.  Others  follow  the  advice  of  many  orthodontists  by  caring  for  the 
deciduous  teeth  with  amalgam  alone  or  in  the  form  of  an  inlay  with 
oxyphosphate  of  copper  for  the  cementing  medium.  A  few  use  inlays 
in  the  deciduous  teeth,  but  those  who  use  gutta  percha  appear  for  the 
greater  part  to  be  doing  so  with  an  apology. 


CEMENT  AND  ALLOY 

A  mixture  of  thin  cement  and  alloy  fillings  has  been  recommended 
by  some  for  operations  in  remote  parts  of  the  mouth  where  it  is  desired 
to  prolong  the  durability  of  a  cement  filling.  The  main  object  of  the 
alloy  is  to  protect  the  cement  somewhat  from  the  fluids  of  the  mouth. 

With  the  development  of  the  inlay  method  a  tendency  has  developed 
to  use  cement  and  alloy  in  the  form  of  an  amalgam  inlay  (Fig.  321), 
instead  of  in  this  combination.  If  cement  and  alloy  are  to  be  used 
the  cement  should  be  slow  setting.  A  comparatively  slow  setting  cement 
is  mixed  to  a  creamy  consistence  and  the  alloy  then  worked  into  it  to 
the  desired  consistence. 

The  advantages  of  cement  and  alloy  over  amalgam  are  adhesiveness 
and  non-conductivity.  Its  advantages  over  cement  are  durability  and 
hardness.  This  combination  has  been  of  service  in  restoring  badly 
decayed  teeth  and  in  some  sections  still  seems  to  be  in  favor,  but,  like 
gutta-percha,  it  is  being  eliminated  by  the  recent  demands  for  better 
oral  hygienic  conditions. 

BASIC  ZINC  PHOSPHATES  AND  SILICATE  CEMENTS 

This  combination  is  of  comparatively  recent  origin  and  has  been 
found  necessary  to  carry  out  the  insertion  of  the  silicate  cements.  One 
of  the  first  observations  in  the  use  of  the  silicate  cements  was  that  they 
were  irritant  to  the  pulps  of  the  teeth.  This  is  also  true  of  the  basic 
zinc  phosphates,  especially  when  the  acid  is  present  in  comparatively 
large  quantities,  as  wdien  the  cement  is  mixed  to  a  creamy  consistence 
for  retaining  inlays,  bands,  crowns,  etc.  There  is,  however,  more  irrita- 
tion from  the  silicate  cements  as  at  present  introduced  than  there  is 
with  the  basic  zinc  phosphates.  To  correct  this  to  some  extent,  many 
have  advocated  placing  a  layer  of  basic  zinc  phosphate  which  had  been 
mixed  rather  stiflf  along  the  pulpal  wall  of  the  cavity. 


332  COM  BIN  AT  KIN  FILLINGS 

As  a  rule,  cavities  reiiuirino-  a  lining  material  have  only  a  thin  lamina 
of  dentin  over  the  pulp,  and  care  uuist  be  exercised  not  to  use  the  basic 
zinc  phosphate  so  stitt"  that  nuich  pressure  is  re(juired  to  place  it.  It  is 
bettei',  however,  to  have  the  cement  as  basic  as  possible,  and  get  the 
minimum  of  pressure  in  placing  and  the  required  adhesion.  It  is  often 
best  to  precede  the  insertion  of  the  basic  zinc  phosphate  with  a  layer 
of  one  of  the  lining  varnishes,  while  at  other  times  the  lining  varnish 
maybe  used  and  the  basic  zinc  phosphate  dispensed  with.  The  greater 
adhesion  of  the  basic  zinc  phosphates  over  the  silicate  cements  is  keeping 
them  in  favor  for  filling  undercuts  and  the  deeper  portions  of  all  cavities 
regardless  of  whether  it  is  actually  necessary  or  not. 

The  basic  zinc  j)hosphates  will  uncjuestionably  add  more  to  the 
strength  of  teeth  with  frail  walls  than  the  silicate  cements  now  in  use, 
although  the  latter  are  not  entirely  devoid  of  adhesion.  Owing  to  the 
uncertainty  of  the  solubility  of  the  silicate  cements,  the  tendency  is  to 
leave  more  unsupported  enamel  when  using  it  than  when  using  other 
materials  except  the  basic  zinc  pho.sphates. 

Cavities  that  have  ordinarily  been  extended  to  areas  of  relative  immu- 
nity for  the  reception  of  other  materials  are  being  filled  with  basic  zinc 
phosphate  and  silicate  cements  without  such  extension.  Just  what 
the  judgment  of  the  profession  will  be  regarding  this  practice  cannot  be 
stated,  but  it  is  probable  that  more  failures  will  attend  the  use  of  the 
silicate  without  extension  than  would  occur  from  a  dissolving  of  them 
and  the  result  will  be  more  extension  of  the  cavities. 


CHAPTER    XIII 
RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

By  W.  a.  capon,  D.D.Sc. 

This  branch  of  operative  dentistry  has  for  many  years  been  an 
important  factor  in  the  preservation  of  teeth,  particularly  those  of  poor 
structure  precluding-  the  use  of  ordinary  means  of  restoration  through 
the  use  of  mallet  or  hand  pressure  gold  fillings.  The  term  inlay,  accu- 
rately speaking,  may  be  applied  to  any  substance  placed  in  the  cavity  as 
in  one  piece  and  held  in  position  by  an  adhesive  cement,  but  porcelain 
and  gold  are  the  generally  accepted  materials  when  "making  an  inlay'' 
is  spoken  of. 

The  process  of  making  a  porcelain  inlay  is  practically  the  same  at 
present  as  when  first  introduced  some  twenty  years  ago,  but  the  advent 
of  the  casting  machine  for  gold  has  revolutionized  that  work  and  made 
it  possible  for  every  dentist  to  make  inlays  in  a  scientific  and  practical 
manner  and  enlarge  his  usefulness  as  an  operator  to  the  advantage  of 
all  concerned. 

The  desire  for  a  more  natural  appearing  material  for  tooth  restora- 
tion existed  many  years  before  practical  means  were  discovered,  and 
much  energy  was  expended  toward  making  porcelain  in  some  form  fulfil 
that  requirement.  Pieces  of  porcelain  matching  the  natural  tooth  have 
in  times  past  been  ground  to  fit  the  cavities  and  then  cemented  to  place, 
but  this  class  of  work  is  hardly  feasible  except  in  labial  cavities  or  some 
regular  surface  of  the  front  teeth.  Ready-made  porcelain  inlays  have 
been  kept  in  stock  for  years  at  the  dental  depots.  They  are  in  the 
form  of  rods  in  various  shades  and  diameters,  while  others  of  different 
shapes  and  sizes  are  ground  to  fit  the  cavities  and  finally  cemented  in 
place,  after  which  they  are  polished. 

Some,  however,  instead  of  being  ground  to  fit  the  cavity,  recjuire  the 
cavity  to  be  ground  to  fit  them  (Fig.  323). 

Dr.  Geo.  H.  Weagant,  devised  a  set  of  instruments  (Fig.  324)  suitable 
for  this  process,  consisting  of  five  trephines  of  consecutive  sizes,  made  of 
copper  charged  with  diamond  dust.  These  instruments  are  intended  to 
cut  pieces  of  porcelain  out  of  an  artificial  tooth  that  matches  the  color 
of  the  natural  tooth,  and  the  cavity  in  the  natural  tooth  is  prepared  with 
one  of  Dr.  How's  inlay  burs  (Fig.  325)  corresponding  in  size  to  the  trephine. 
This  method  has  several  serious  objections,  one  of  the  principal  being 
that,  in  order  to  give  the  cavity  a  circular  shape,  much  tooth  structure  is 

(333) 


;^34 


liKSTOUATlOS   OF   TEETH  BY  (KMEXTKJJ  J \ LAYS 


usiiallv  .sacrificed.  Take  for  example  tlie  decayed  spot  .shown  in  1*1^.  ''i2(\. 
This  would  have  to  be  enlarged  as  in  Fig.  32(3  b — which  is  a  .serious 
objection. 

Fig.  323 


100000 


lOOOOOOOono 

OOOOooogCSE 


Porcelain  cavity  stoppers. 


Fig.  324 


Fig.  325 


Dr.  Weagant's  diamond  trephines. 


Dr.  How's  inlay  burs. 


Fig  326  As  early  as  1882  Dr.  Herbert  advocated  glass 

fillings.  These  were  made  by  taking  impressions 
of  the  cavity  in  wax  and  making  two  moulds  in 
.some  such  material  as  plaster  or  asbestos.  The 
ground  glass  was  then  flowed  into  the  first  mould, 
in  which  most  of  the  shrinkage  occurred.  The 
a  I,  partly  formed  filling  was  then  removed  and  placed 

in  the  second  mould,  when  more  glass  was  added 
until  the  filling  was  complete.  Even  with  this  crude  method  the  results 
were  fairly  satisfactory,  although  the  margins  were  far  from  perfect  and 
the  glass  was  permeable  to  such  an  extent  as  to  blacken;  nevertheless, 
fillings  were  made  that  preserved  the  teeth  for  years. 

In  1887  Dr.  C.  H.  I^and  made  mechanically  perfect  edges  possible  by 
devising  the  metal  matrix.  Dr.  Land  used  both  gold  and  platinum,  but 
found  the  latter  preferable,  as  platinum  could  be  adapted  with  a  facility 
equal  to  gold,  and  allowed  the  use  of  high  fusing  tooth  body  much 
stronger  and  less  likely  to  deteriorate  than  bodies  capable  of  being  fused 


li/'JS'I'OJiATION   OF   TEETH   BY  CEMENTED  INLAYS  -S35 

on  ^()1(1,  which  oF  necessity  re(|nires  so  hir^e  ii  j)ercent;itfe  oF  ^hiss  that 
thev,  like  the  filHiios  of  Ilerhst,  lucked  permanence  of  gloss  and  color. 

From  Land's  discovery  dates  all  effective  porcelain  fillings.  Before 
this,  pieces  of  porcelain  had  been  ground  to  fit  labial  cavities  with  fair 
results,  but  the  accurate  adaptation  of  porcelain  to  proximal  cavities 
was  impossible  until  the  metal  matrix  was  evolved. 

It  is  claimed  that  inlays  are  idealistic  in  their  results,  and  this  is 
undoubtedly  true,  providing  certain  considerations  are  adhered  to.  But 
it  being  impossible  to  make  one  material  perfect  under  all  circumstances, 
it  is  then  necessary  to  resort  to  a  combination  that  will  lead  to  the  best 
results.  Porcelain  inlays  are  ideal  because  when  properly  made  they 
restore  the  tooth  more  closely  to  its  original  and  natural  appearance 
than  gold  or  any  other  material.  Its  resisting  qualities  are  much  inferior 
to  gold,  therefore  its  value  decreases  if  appearance  and  artistic  quality 
are  not  first  considerations.  Gold  in  inlay  form  is  then  used,  which 
justifies  us  in  classifying  the  cemented  inlay  as  an  ideal  means  of 
restoration,  unequalled  and  unchallenged. 

In  other  words,  the  use  of  porcelain  for  anterior  teeth  and  gold  for  the 
wear  and  tear  of  posterior  teeth  have  all  the  characteristic  of  ideal  fillings 
because  they  exclude  germs  of  decay  and  preclude  from  growth  those 
that  enter.  An  inlay  is  a  non-conductor  of  heat;  it  adheres  to  cavity 
walls,  its  manipulation  is  easy  to  the  patient  and  conservative  of  tooth 
structure.    It  has  : 

1.  Resistance  to  wear  of  mastication. 

2.  Resistance  to  the  action  of  oral  fluids. 

3.  Harmony  of  color  when  porcelain  is  used. 

4.  Exclusion  of  bacteria  and  preclusion  from  growth  of  those  that 
may  enter  the  margin. 

5.  Non-conductivity  of  heat  and  electricity. 

6.  Manipulation  easy  to  patient. 

7.  Manipulation  easy  to  operator. 

8.  Manipulation  not  destructive  of  healthy  tooth  structure. 

9.  Re-insertion  with  little  preparation. 

10.  Duplication,  which  means  that  in  many  (cavity  preparation) 
instances  a  duplicate  is  made  and  reserved  by  the  operator  for  use  in 
case  of  accident  to  the  original. 

The  success  of  an  inlay  will  depend  largely  upon  four  points  of  differ- 
ence between  its  cavity  preparation  and  that  for  those  of  foil,  gutta- 
percha, amalgam,  or  cements,  viz.,  upright  walls,  square  enamel  edges, 
no  undercuts,  and  depth.  The  walls  being  perpendicular  or  nearly  so, 
allow^  the  easy  withdrawal  of  the  metal  matrix  either  of  platinum  or  gold, 
or  in  the  case  of  the  impression  for  casting  with  wax  or  any  material  for 
the  purpose  of  making  a  model.  The  enamel  edges  are  made  square 
so  that  the  inlay  will  have  no  overhanging  frail  edges  of  porcelain. 

An  undercut  will  prevent  the  easv  removal  of  the  matrix  frequently 


336 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 


(Ji.stortiiii;  it,  and  when  nsiiin;  wax  not  even  the  sliirhtest  nndcrciit  is 
perinissihlc.  In  connoction  with  porcelain,  depth  of  cavity  has  much 
to  do  with  retention  in  fact;  it  is  more  imj)ortant  than  various  kevs  and 
irregular  forms  advocated  by  many  writers  on  this  subject.  Unfor- 
tunately we  cannot  always  get  sufKcient  depth,  and,  on  the  contrary, 
many  cavities,  when  entirely  cleared  of  decay,  are  too  deep  to  obtain 
an  uiunutilated  matrix  particularly  with  platinum;  however,  when  this 
condition  exists  it  is  an  easy  matter  to  reduce  it  by  partiallv  filling 
with  cement  or  gutta-percha. 

The  advantages  of  depth  are  retention,  .strength,  through  quantity 
of  material  and  ])urity  of  shade  by  having  sufficient  volume  of  porcelain 
which  assists  materially  in  reducing  the  opacity  caused  by  tlie  cement. 

This  rule  pertaining  to  deep  cavities  has  not  the  same  value  when 
applied  to  the  cast  gold  inlay,  and  it  is  well  to  note  that  the  same  rules 
which  apply  to  porcelain  inlays  are  applicable  to  matrix  gold  inlays, 
excepting  that  point  pertaining  to  shading,  because  cavities  prepared 
for  matrices  have  always  the  burnishing  feature  prominent,  which  means 
curves  and  all  surfaces  accessible  to  the  burnisher. 

The  following  representations  of  various  cavities  in  natural  teeth 
where  porcelain  is  indicated  and  applicable  are  shown  with  the  .same 
cavity  prepared  and  ready  for  the  matrix.  By  this  means  the  student 
will  readily  note  what  is  re(juisite  and  necessary  without  detailed  descrip- 
tion and  technical  nomenclature. 


Fig.  327 


Fig.  328 


Fig.  329 


Figs.  327  to  334  show  simple  cavities,  and  in  each  case  the  ])order  has 
been  extended  beyond  the  outline  of  decay,  for  the  same  consideration 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS  337 

with  rosjjoct  to  extoiisioii  is  a{)pliecl  in  this  class  of  work  as  if  the  cavity 
were  to  be  filled  with  gold. 

i'n;.  3.J0  Fia.  331  '  Fig.  332 


Figs.  335  and  336  are  in  the  same  class  but  are  more  difficult,  for  they 
have  resulted  from  another  cause,  viz.,  abrasion  or  erosion,  and  it  is  noted 
particularly  because  this  condition  is  common,  and  the  cavity  prepar- 
ation much  more  difficult.    The  depth  is  insufficient  and  the  margins  are 

Fig.  333  Fig.  334 


never  defined,  which  necessitates  extensive  cutting  into  hard  and  unusu- 
ally sensitive  dentin,  and  as  this  kind  of  cavity  is  almost  as  common 
22 


338  RESTORATIOS   OF   TEETH   BY  VEMESTED  IXLAYS 

ill  lower  teetli  tlie  difHculty  of  preparation  and  (general  uianipulatioii  is 
increased.     This  applies  to  all  labial  cavities  and  is  noticed  more  in 

Ik;.  3.5.")  Fig.  336 


porcelain  operations,  because  when  the  cavity  is  ready  the  matrix  mnst 
be  held  in  position  firmly,  a  procedure  interfered  with  by  the  lower  lip 
and  the  saHva.  The  use  of  rui)i)er  dam  is  not  desirable  because  it  reduces 
the  working  space,  but  it  has  other  advantages  occasionally. 


Fig.  337  Fig.   338 


Figs.  .'337  to  340  show  cavities  presenting  greater  difficulties  both  in 
preparation    and    general    manipulation.      Cavities    in    such    positions 


RESTOHATION  OF   TEETH  BY  CEMESTED  I X LAYS    ^      3:59 

must  have  j)lenty  of  sj)ace  hetwecMi  theadjoiiiiiiM;  footli,  otlicnvise  a  matrix 
cannot  be  withdrawn  or  the  finished  fillinn;  inserted.     Sometimes  it  is 

Kid.  AM  Imi;.  311 


impossible  to  get  sufficient  space  for  drawing  the  matrix  without  dis- 
tortion ;  in  such  instances  the  cavity  is  prepared  with  this  point  as  a  first 
consideration.    Fig.  346  shows  a  cavity  of  this  kind.    If  there  is  not  much 

Fig.  342  Fig.  343  Fig.  344 


difference  in  outhne  of  the  cavity  labially  or  lingually,  choose  the  labial 
side  to  extract  the  matrix;  or  if  cutting  the  labial  margins  does  not  inter- 


340  RESTORATIOS  OF   TEETH  BY  C  EM  EST  El)  J. \  LAYS 

fere  \\  itli  (he  welfare  ol"  the  foot  li,  resort  to  tlits  assist  a  nee  in  preference  to 
(liflieiiltics  of  lingual  matrix  extractions.  In  Figs.  338  and  340  the  matrix 
under  ordinary  conditions  will  be  withdrawn  linifuall y.     Figs.  339  and  341 

Fk;.   .'M.-)  I'k;.   3-16 


show  uncertain  incisal  edges  which  are  reduced  in  Figs.  342  and  344; 
thereft)re  the  difficulties  of  drawing  a  matrix  in  this  case  are  very  much 
reduced,  for  the  cavity  is  so  large  that  working  space  is  greatly  extended. 
Large  proximal  cavities  of  Fig.  341  type,  where  the  incisal  edge  is  of 
greater  strength  and  is  retained,  are  very  difficult  and  frequent.     The 

Fig.  347  Fir,.  348 


matrix  formation  requires  skill  and  patience,  but  the  reward  is  dura- 
bility— for  the  inlay  in  this  case  is  thoroughly  protected  and  is  rarely 
unseated. 


UESTORAriON  OF  TEETH  BY  CEMENTED  INLAYS  341 

Figs.  347  and  34S  sliow  a  cavity  on  the  gingival  l)()n]rr  extending  under 
the  gum  margin  and  involving  a  considerable  portion  of  the  tooth  mesially 

Fiu.  349  FiLi.  350 


and  distally.  It  is  a  typical  representation  of  this  form  of  cavity  and  the 
position  is  one  demanding  a  restoration  with  porcelain.  The  cavity 
walls  are  governed  bv  its  extent,  for  the  matrix  will  warp  if  a  strict 
rule  of  upright  walls  is  carried  out  here.    The  cervical  wall  will  not  be 

Fig.  351  Fig.  352  Fig.  353 


at  right  angles  to  the  pulpal  wall  or  floor,  or  if  so  made  they  cannot  be 
of  that  form  at  the  extreme  mesial  and  distal  border;  therefore,  in  these 


342  RESTORATION  OF   TEETH   BY  C  EM  EST  EI)  I  \  LAYS 

cavities  strict  adherence  to  a  rif^lit  aii<ile  uj)rio;lit  wall  is  not  possible  for 
the  best  result.  When  the  matrix  is  burnished  it  should  be  packed  with 
gum  camphor  in  preference  to  other  materials  recommended.  It  is  not 
alwavs  possible  to  make  a  verv  extensive  inlay  of  this  kind  of  one  piece, 
therefore  it  should  be  divided  at  the  median  line  of  tooth  and  two 
operations  made. 

Figs.  349  to  353  represent  extensive  proximal  cavities  or  fractures 
extending  to  the  incisal  edge,  and  at  a  position  where  porcelain  is  of 
great  importance.  The  apparent  insufficient  anchorage  deters  many 
operators  from  using  porcelain,  and  the  preparation  of  these  cavities  is 
the  cause  of  more  different  opinions  than  any  other.  It  is  claimed  that 
without  a  key  or  step  on  the  lingual  surface  porcelain  will  not  be  retained 
by  the  ordinarily  prepared  cavity,  and  unneces.sary  cutting  of  good  tooth 
structure  is  taught  with  most  deplorable  results — in  many  instances, 
irregularitv  of  cavity  and  its  borders  increase  the  matrix-formation 
difficulties,  therefore  a  simple  preparation  is  taken  advantage  of.  AVith 
few  exceptions  the  cavity  can  be  prepared  similarly  to  Fig.  342,  defining 
the  labial  and  lingual  walls  and  anchorage  increased  by  a  groove  with  a 
round  bur  at  the  gingival  border  resembling  a  deep  undercut,  as  for  a 
gold  filling.  Anchorage  is  also  increased  by  grooving  between  the  enamel 
plates  at  the  incisal  edge.  The  matrix  must  be  burnished  to  these  sur- 
faces, otherwise  the  value  of  the  preparation  is  lost.  The  labial  outline, 
Fig.  352,  can  be  varied  in  many  ways,  but  angles  are  to  be  avoided  when- 
ever possible.  ^  ery  often  the  corner  is  of  the  form  of  an  irregular  tri- 
angle tapering  to  a  wedge  point  at  the  cutting  edge.  The  porcelain  at 
that  point  is  very  frail  and  will  break,  leaving  an  irreparable  notch. 
To  avoid  this,  cut  an  axial  wall  as  in  Fig.  353,  and  thus  make  a  body  of 
porcelain,  giving  strength  at  a  weak  point.  This  same  cavity  is  sometimes 
so  extensive  that  anchorage  is  made  by  wire  pins  or  staples.  In  instances 
where  the  incisal  section  of  the  tooth  has  been  lost  by  accident  or  decay, 
this  process  of  retention  is  preferable  and  highly  recommended  for  per- 
manency. Fig.  354  shows  a  central  tooth,  a  matrix,  and  the  porcelain 
section  with  wire  anchorage.  This  case  shows  loss  of  one-fourth  of  the 
tooth  and  the  cavity  made  by  cutting  the  dentin  to  the  required  depth,  an 
operation  possible  with  few  exceptions.  The  enamel  edges  are  made  true 
by  a  flat  stone,  after  which  the  matrix  is  made  of  the  walls  and  edges,  and 
shown  without  a  floor.  The  wire  is  iridioplatinum,  gauge  24,  made  in  the 
form  of  a  staple  or  loop,  and  inserted  w^hile  the  matrix  is  in  place;  with 
these  in  position,  porcelain  in  paste  form  is  pressed  over  all  and  excess 
moisture  is  absorbed  by  holding  a  napkin  or  bibulous  paper  to  its  surface. 
The  combination  is  carefully  taken  from  the  cavity  and  fused,  thus 
forming  a  V)ase  with  a  wire  loop  or  pins  held  securely  without  soldering. 
This  foundation  is  now  placed  on  the  tooth  and  matrix  edges  thoroughly 
burnished,  after  which  the  operation  is  completed  by  repeated  fusing. 
When  the  matrix  is  removed  the  contoured  tip  w  ill  resemble  the  third 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 


343 


section  of  F\<^.  354,  and  is  ready  for  comentin(,^  AVhen  the  first  porcelain 
is  applied  it  will  likely  fill  the  loop,  but  this  nuist  not  he  corrected  until 
after  fusintj,  w  hen  the  porcelain  is  easily  broken  away  with  blunt  pliers. 
Freijuentlv  the  staple  or  loop  is  inverted  to  suit  conditions,  but  the  form 
represented  is  the  most  durable  in  every  particular.     The  difficulties 


Vu:.  3.-) 4 


of  this  operation  are  increased  i>y  the  irreo;ular  form  of  fracture,  for 
usuallv  thev  extend  lingually  and  frequently  quite  to  the  gum  margin; 
a  restoration  of  this  kind  should  not  be  attempted  until  the  operator  has 
had  considerable  practice,  for  the  making  of  an  incisal  tip  acceptably  is 
one  of  the  most  difficult  operations. 

Fio-s.  355  to  364  show  cavities  in  biscupids  and  molars  for  porcelain 
inlavs.  The  forms  are  very  similar  and  directions  for  cavity  technique  are 
applicable  in  either  instance.    The  value  of  porcelain  in  these  positions 


Fig.  355 


Fig.  356 


Fig.  357 


is  questioned  because  the  force  of  contact  is  increased  and  the  esthetic 
value  is  decreased.  There  are  many  exceptions,  and  the  opportunities 
exist  in  mesial  surfaces  of  superior  biscupids  and  molars.  The  occlusion 
is  the  first  consideration,  size  and  depth  of  cavity  are  next,  although  the 
latter  is  generally  regulated  by  a  step  as  shown  in  the  sketches.    This  step 


344 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 


is  made  of  cement  or  gutta-percha  and  not  of  llie  same  extent  as  if  pre- 
paring for  a  gold  inlay  (I'ig-  365).  The  gingival  borders  are  more  curved 
and   the  step  is  rounded  and    alh)\vaiict>  made  for  greater  (hickness  of 


Fig.  35S 


Fig.  350 


porcelain  at  the  occlusal  surface.  The  inlay  will  he  more  secure  with- 
out a  step  or  interior  preparation  with  any  other  material,  hut  bicuspid 
and  molar  cavities  are  usually  too  deep  for  successful  matrix  formation. 


Fig.  360 


Fig.  361 


If  this  can  be  accomplished,  there  still  remains  the  difficulty  of  placing 
the  inlay,  becau.se  of  greater  bulk  than  it  is  possible  to  get  space  for; 
however,  there  can  be  no  .set  rule,  circumstances  and  good  judgment 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS  345 

must  be  factors  at  all  times.     In  any  case  the  cavity  must  not  extend 
into  the  sulci  between  cusps  unless   the  sulci  are  of   sufficient  si/e  to 

Fic.   302  Fi.j.  303 


assure  strength  of  porcelain.     Figs.  360,   362,   and   364  show  enamel 
surface  edges  without  any  extension  to  the  sulci. 

Figs.  365,  366,  and  367  represent  cavity  preparation  for  gold  inlays  in 
molar  and  bicuspids,  showing  the  locking  or  mechanical  retention  gener- 
ally advocated.  By  this  preparation  it  is  possible  to  reduce  the  thickness 
of  gold  without  mterference  with  durability,  and  the  amount  of  cement 

Fig.  364  Fig.  365 


required  is  also  reduced  to  the  minimum.  Note  the  square  edges  and 
angular  lines  at  the  gingival  border  which  is  not  permissible  with  a 
metal  matrix,  but  wax  in  proper  mouldable  state  will  adjust  itself  readily 


34() 


RESTORATIOX  OF   TEETH   BY  CEMENTED  INLAYS 


at  these  points.  A  cluiint'ered  edge  is  not  incorrect  in  many  instances;  in 
fact,  some  teachers  contend  that  this  is  a  proper  method.  It  would  seem 
that  a  hurnishcd  cdo;e  is  easier  obtained  when  the  cavity  edge  has  a 
bevel;  but  it  is  one  of  those  points  frequently  discussed,  and  the  scjuare 


P'lc;.  30G 


Fi.;.  Mu 


w 

■^^^ 

r^^^^ 

1  / 

tm^ 

edge  and  bevelled  edge  preparation  have  each  an  equal  number  of 
adherents.  Fig.  306  shows  a  double  compound  cavity  which  is  very 
common  in  bicuspids  and  molars  and  not  always  possible  to  restore  by  a 
casting  in  one  piece.  To  draw  the  wax  without  change  the  axial  walls 
must  converge  slightly  toward  the  occlusal  surface  and  the  cavity  walls 
having  the  same  tendency  toward  the  outer  border.  It  is  not  expected 
that  the  locking  or  keying  system  shown  in  365  and  367  can  be  used  in 
every  case  or  without  variation.     Many  cases  have  insufficient  crown  iov 


Fig.   368 


Koach's  suction  wax  carver. 


this  application;  in  these  a  post  or  pins  are  recommended.  Frequently 
there  is  considerable  bulk  of  wax  owing  to  certain  conditions  not  always 
po.ssible  to  avoid,  which  if  reproduced  in  gold  will  increase  the  cost  of 
the  operation  very  noticeably.  The  wax  can  be  reduced  by  melting  the 
surface,  which  will  be  cemented.     Considerable  undercut  can  be  made 


FORMATION  OF  THE  MATRIX  FOR  PORCELAIN 


347 


which  will  increase  retention  of  the  inhiy.  The  best  instruments  for 
this  purpose  consist  of  hollow  points  with  rubber  tubes  attached. 

The  point  is  heated  and  applied  to  the  wax,  and  sucking  the  tube  will 
draw  the  melted  wax  into  a  small  section  filled  with  cotton.  Electric 
pcints  of  various  forms  are  also  used,  and  the  simpler  method  is  a  hot 
amalgam  burnisher,  wiping  the  wax  from  the  point  after  each  application. 

The  formation  of  cavities  is  greatly  assisted  by  special  burs  and  chisels 
of  various  sizes  and  curves. 


Fia.  369 


10 

15 

20 

10 

10 

15 

15 

20 

20 

10 

15 

20 

ao 

4 

5 

6 

6 

6 

8 

8 

9 

9 

6 

8 

9 

6 

6 

6 

6 

12 
L 

12 
R 

12 
L 

12 
E 

12 
L 

12 

12 

12 

12 

12 

6  6  7  8  8  10 

Simpson's  automatic  chisels  (proximal). 


12 


13 


FORMATION  OF  THE  MATRIX  FOR  PORCELAIN 


The  difficulties  pertaining  to  the  making  of  a  matrix  are  much  reduced 
by  having  plenty  of  space  between  the  teeth,  and  this  must  be  obtained 
prior  to  the  operation  by  means  of  tape  cotton,  or  rubber  wedges.  INIe- 
chanical  appliances  may  be  used  as  an  assistant  when  the  inlay  is  made 
and  the  space  for  easy  insertion  is  insufficient,  but  holding  the  teeth  apart 
while  making  the  matrix  is  usually  an  interference  that  can  be  avoided 
by  giving  this  part  of  the  work  proper  consideration.  Room  to  work 
is  a  good  rule  to  follow  in  any  operation,  but  it  is  positively  necessary 
with  the  inlay,  because  the  mass  is  hard  and  unyielding  with  breakable 
edges.  It  must  be  placed  while  the  cement  is  soft,  and  without  delay,  and 
the  slightest  interference  may  mean  much  loss  of  time  and  poor  results. 

A  gold  inlay  can  be  forced  to  place  without  damage,  but  an  unpleasant 
experience  or  two  with  porcelain  will  demonstrate  the  desirability  of 
having  plenty  of  space. 

The  reproduction  of  the  form  of  a  cavity  in  foil  for  an  inlay  is  called 
the  matrix  in  which  the  porcelain  is  moulded  by  heating  to  a  degree 
required  to  fuse  the  component  parts  of  the  material  to  a  vitrified  mass. 


34S 


RESrORATIOX  OF   TEETH  BY  CEME.XTED  J. \  LAYS 


"^riio  mctiil  most  j^^cii orally  used  is  pure  j)l:itiiiiiiii  foil,  ji^aa  of  an  inch 
in  thickness.  (Jold  foil  Xo.  4U  is  also  largely  iisi-d,  but  only  in  connec- 
tion with  a  low  fusing  porcelain  which  fuses  at  a  temperature  of  300° 
to  'M)°  less  than  <(ol(l.  Platimnn  has  the  advantaf^e  in  the  fact  that  it 
cannot  he  affected  hy  any  heat  recjuired  to  fuse  the  lu'irhcst  f^rade  ])orce- 
lain.  it  is  not  so  (hictilc,  or  so  easily  moulded  to  form,  hut  this  dis- 
advanta(,re  is  countci-halanced  hy  its  stability .  whi(  h  allows  ^n-eater 
freedom  from  care  as  to  the  changing  of  its  form  while  filling  with 
j)orcelain. 

A  gold  matrix  is  invariably  invested  to  prevent  its  changing  form 
and  j)rotect  it  from  overheat.  This  re(|uires  time  and  care,  theretV^re 
platinum  is  more  desirable  from  nuuiy  ])oiiits,  and  ])ractice  will  assist 
greatly  toward  easy  nuinij)ulation.  I'here  has  been  much  discussion  in 
the  past  upon  the  proper  thickness,  but  it  is  now  generally  conceded  that 
ToVtt  f*'  '^'1  '"<■'!  '^^■'l'  ~^"'t  !'"  cases  better  than  any  degree  thinner  or 
thicker.  A  thinner  material  has  not  the  stretching  (piality,  and  anything 
heavier  will  cause  a  thicker  cement  line. 


Fig.  370 


■H 

Hp^Sji^^^HLj^^RH 

■;'^- 

HRh 

1 

^^H^^^^ 

Jl^^l^ 

^1 

A  simple  cavity  on  the  labial  .surface  of  a  central  will  serve  to  illustrate 
the  mode  of  procedure,  which  is  the  cutting  of  a  scjuare  section  of  the 
foil  sufficientlv  large  to  extend  over  the  adjoiTiing  teeth,  holding  the 
corners  in  the  maimer  of  Fig.  370,  and  while  held  securely  by  the  fingers. 
press  the  foil  over  the  cavity  with  some  material  such  as  spunk,  cotton, 
small  chamois  disks,  or  a  .soft  rubber  point  like  a  j)encil  end,  and  in  this 
manner  the  cavitv  will  be  outlined  on  the  foil  and  that  portion  covering 
the  cavitv  concaved  so  there  can  be  no  mistake  as  to  what  jjortion  is  to  be 
burnished.  Then  use  ball-])ointed  burnishers  of  various  sizes,  such  a.s 
amalgam  instruments  shown  in  Figs.  371  to  375,  and  gently  rotate,  grad- 
ually pushing  the  burm'shed  surface  to  the  cavity  walls  and  floor,  using 
care  not  to  break  the  margins.  The  metal  will  probably  split  or  break 
as  it  is  forced  to  place,  but  unless  extremely  ruptured,  it  will  not  inter- 


FURMATION  OF  TflJ'J  MATli/X  FOli  PORCELAIN 


;j49 


Fig.  371 


Fig.  .372 


'T 


•'^i 


Fig.  .37.3 


fere  with  final  results.    When  th(>  Interior  j)()rti()n  i.s  fairly  fitted,  packed 
with  spunk,  cotton,  or  ^uni  canij)li()r,  and  held  .securely  with  a  hluJit 
instrument,  a  flat,  blunt  instrument  should  he  used  (o  n;et  perfect  mar- 
gins.     Then  the  packing  i.s  removed  (ex- 
cept when  using  camj)hor,  which  is  l)urnt 
out),  the  matrix  released  with  very  fine 
pointed  pliers,  and  results  noted. 

If  satisfactory,  the  next  step  is  filling 
the  mould  with  porcelain. 

Platinum  foil  should  be  thoroughly 
annealed  in  the  furnace  muffle;  the  heat 
required  to  improve  its  softness  is  at  least 
2200°  F.  The  foil  purchased  at  the  pres- 
ent time  is  usually  ready  for  making  the 
matrix,  having  already  been  thoroughly 
softened  at  a  very  high  temperature.  A 
matrix  of  complex  character  will  require 
more  than  usual  burnishing,  which  will 
have  a  tendency  to  make  the  metal  harsh. 
It  can  then  be  re-annealed  to  advantage, 
providing  the  temperature  is  not  less  than 
the  degree  already  mentioned. 

An  excess  of  material  is  recommended 
on  labial  cavities  for  the  purpose  of 
holding  securely,  but  in  other  places  the 
reverse  is  desired.  Notably  on  proximal 
surfaces,  where  the  excess  will  interfere 
with  removal  after  taking  the  form  of  the 
tooth.  Burnishing  the  matrix  in  proximal 
cavities,  corners,  and  tips  is  greatly  as- 
sisted by  strips  of  either  cotton,  rubber 
dam,  or  goldbeater's  skin  held  securely 
over  the  metal,  insuring  its  proper  posi- 
tion and  preventing  tearing  on  the  sharp 
cavity  edges  (Fig.  376).  Avoid  lapping 
or  folding  of  matrix  on  cavity  edges. 

After  the  matrix  is  made  the  next  pro- 
cedure is  filling  it  with  porcelain.  This  is 
done  by  holding  the  mould  in  straight, 
fine-pointed  pliers,  applying  the  porcelain 
with  a  fine  sable  pencil  brush,  or  the  end 
of  a  spatula  made  for  the  purpose  (Fig. 

377).  The  porcelain  powder  is  mixed  with  pure  water,  distilled  prefer- 
ably, into  a  stiflf  paste,  and  after  applying  it  is  shaken  to  position  either 
by  tapping  or  drawing  the  serrated  instrument  handle  across  the  pliers. 


yjo 


HESTORATKJX  OF   TKETII   BY  CEMESTEl)  I. SLAYS 


This  jarring  hrinif.s  the  moisture  to  the  surface,  and  after  tracing  the 
cavity  outline  and  removing  excess  with  brush,  it  is  laid  face  down  on 
a  clean  towel,  bibulous  or  blotting  paper,  which  absorbs  the  excessive 


I-k;.  374 


■^         6        ^  00  789 

Reeves'  set  of  inlay  burnishers. 

moisture.  The  inlay  is  then  dried  out  in  front  of  the  furnace 
muffle,  gradually  pushed  into  the  furnace,  and  fused.  Too  rapid 
drying  will  cause  porcelain  to  jump  from  the  mould.  A  high 
fusing  porcelain  mixed  into  a  stiff  paste  will  shrink  about 
one-fifth  its  bulk,  therefore  a  second  or  third  fusing  is  required 
before  the  inlay  can  be  called  finished.  If  the  porcelain  is 
thin  its  proportion  of  shrinkage  will  be  greater,  and  it  will  not 
bridge  or  carry  its  weight  across  any  tear  or  aperture  that  may 
exist  in  the  bottom  of  the  matrix;  and  in  deep  cavities  this  con- 
dition is  nearly  always  present,  therefore  it  is  necessary  to  always 
turn  the  matrix  wrong  side  up  and  carefully  note  its  condition. 
Clean  off  any  excess  with  the  brush  and  thus  avoid  a  misfit,  for 
it  is  impossible  to  remove  fused  porcelain  without  distorting 
the  matrix  or  totally  destroying  the  work  up  to  this  point. 

The  first  fusing  is  usually  called  "first  bake"  or  "biscuit," 
which  is  a  stage  wherein  the  component  parts  of  porcelain  are 
brought  together  by  the  heat  and  made  into  a  hard,  homo- 
geneous mass  without  gloss. 

It  is  at  this  stage  that  shrinkage  is  most  apparent,  and  it  is  a 
condition  that  exists  in  every  porcelain  operation  of  whatever 
dimensions.    Shrinkage  is  governed  by  quantity  and  qualitv  of 
material  and  is  a  prominent  factor  toward  success  or  failure. 
In  small  inlays  shrinkage  is  of  less  import,  but  in  proportion 
to  size  it  must  be  dealt  with.    This  shrinkage  may  be  sufficient  to  dis- 
tort the  matrix  or  cause  porcelain  to  attach   to  the  matrix  walls.     As 
it  is  never  consistent  it  is  very  important  to  control  it,  but  this  is  only 


FORMATION  OF  THE  MATRIX  FOR  I'ORCELAIX 


.j.ji 


possible  to  a  small   extent.     Shrinkage  towartl  the  matrix  wall  is  most 
desired  and  can  be  assisted  by  a  slight  cut  or  groove  across  its  greatest 


Fiu.   376 


extent,  thereby  giving  the  porcelain  an  impetus  in  that 
direction.  In  large  spaces  much  assistance  in  controlling 
shrinkage  is  derived  from  using  small  particles  of  baked 
porcelain  mixed  with  the  unfused  paste. 

After  the  first  fusing  of  the  inlay  the  excess  platinum  or 
matrix  material  should  be  trimmed,  leaving  a  working 
margin  to  allow  a  refitting  in  the  cavity.  In  small,  simple 
cases  this  may  not  be  necessary,  but  in  the  majority  of 
cavities  it  will  assist  greatly.  If  the  matrix  has  become 
slightlv  altered  bv  shrinkage  or  careless  handling  the 
change  is  noted  at  once  and  corrected.  In  contour  work 
it  will  assist  the  eye  to  determine  where  to  add  or  reduce ; 
in  fact,  there  can  be  only  very  small  argument  against  a  trial 
of  the  embryo  inlay  in  its  place  and  reburnishing  the  cavity 
edges. 

Taking  the  shade  is  the  first  requirement,  as  the  foun- 
dation should  approximate  the  final  shade,  but  after  the 
inlay  is  reburnished  this  question  must  be  settled  in  the 
operator's  mind,  and  the  final  fusing  proceeded  with. 
First,  clean  off  the  inlay  with  a  brush  dipped  in  alcohol  or 
warm  water,  thus  removing  saliva,  blood,  or  any  undesirable 
particles,  then  carefully  fill  any  crevice  caused  by  shrink- 
age or  breakage,  finally  filling  the  matrix  or  building  the 
contour  or  section  as  desired,  always  considering  shrink- 
age. A  second  bake  may  be  sufficient,  but  usually  a 
third  is  required  or  even  a  fourth.  Frequent  firing  is  not 
harmful  providing  the  porcelain  has  not  been  carried  to  a 
finishing  heat  previously.  Shrinkage  must  be  overcome, 
therefore  withdraw  the  work  from  the  furnace  before  it  is  fused  and 
note  its  condition.    (See  Fusing.) 


352  RESTORATION  OF  TEETH  BY  CEMEM  ED  IXLAY,^ 

After  the  iiilav  is  properly  fired  the  matrix  is  removed  hy  tiirniiif;  the 
metal  back  from  the  edge  with  pointed  jjliers,  releasing  the  inlay.     Fre- 


FiG.  370 


Fig.  .577 


Fig.  .'$78 


I 


(piently  small  particles  of  metal  ad- 
here to  the  porcelain.  If  a  pointed 
instrument  fails  use  adi.scarded  bur, 
but  in  lar^^er  inlays  small  cjuantities 
of  adhering  metal  will  make  no  dif- 
ference in  any  way.  'I'he  inlay  is 
now  tried  in  place,  having  the  cavity 
wet,   which   helps   the  porcelain   to 

Ijlend  with  the  natural  tooth,  and  at  this  stage  the  patient  should 
be  shown  the  results,  for  at  a  later  period  the  cement  and  dry- 
ing of  the  tooth  makes  a  change  not  always  satisfactory,  but 
fortunately  this  is  largely  corrected  by  time. 

The  inlay  is  grooved  or  undercut  by  wheel  disks  such  as 
hard-rubber,  corundum,  or  copper  coated  with  diamond  dust. 
An  additional  retention  is  secured  by  using  hydrofluoric  acid. 
This  acid  has  a  great  affinity  for  all  vitrified  surfaces,  therefore 
great  care  is  necessary  that  the  outer  and  finished  surface  is 
thoroughly  protected,  and  the  most  simple  method  is  to  soften 
the  surface  of  a  small  piece  of  paraffin  or  beeswax,  and  embed 
the  inlay  face  downward.  Then  cover  the  exposed  surface 
with  a  few  drops  of  the  hydrofluoric  acid,  and  after  about  five 
minutes  wash  with  a  spray  of  water. 

The  use  of  acid  for  this  purpose  is  very  common,  and  the 
tendency  to  carelessness  is  sometimes  checked  by  a  bad  burn, 
which  is  always  painful  and  very  slow  to  heal.  After  the  inlay 
has  been  subjected  to  acid  it  should  be  soaked  in  alcohol,  which 
will  soften  the  white  scale,  which  is  removed  by  scraping  the 
surface  with  a  sharp  instrument,  and  therein-  give  the  cement 
a  better  attachment  to  the  roughened  surface.  This  is  a  point 
not  generally  considered,  but  it  is  reasonable  and  practical, and 
many  small  inlays  have  been  lost  through  non-observance  of  this  \7 
fact." 

As  the  inlay  is  now  ready  for  inserting  the  tooth  is  dried  and  protected 
from  moisture  either  by  napkins  or  rubber  dam.    The  latter  is  preferable. 


LOW  FUSING  I'ORCELAIN  353 

but  not  netrssarv,  providin^^  the  openitor  can  use  a  napkin  f)roperlv. 
Successful  inlays  depend  upon  perfect  adaptation  and  cenientaticju,  but 
freciuently  the  operation  is  spoiled  through  carelessness  or  a  desire  to 
hurrv  the  case  to  a  finish,  therefore  too  much  stress  cannot  be  placed 
on  this  important  part  of  the  work.  The  cement  shade  should  approxi- 
mate the  shade  of  the  tooth  and  inlay,  must  be  mixed  thoroughly,  and  of 
creamy  consistency  and  of  medium  to  slow  setting  fpialitv.  Applv  it  to 
the  cavity  with  a  small  spatula  tip,  then  gently  press  the  inlav  int(;  posi- 
tion, wipe  off  excess  with  spunk  or  tape,  and  note  the  line  of  demarca- 
tion. If  this  is  satisfactory  hold  the  inlay  in  position  until  the  cement 
has  commenced  to  harden,  then  protect  from  moisture  bv  covering  with 
melted  paraffin,  wax,  sandarac  varnish,  or  chlorapercha.  If  the  inlay 
is  extensive  it  can  be  ligated  with  floss  silk  or  held  bv  a  wedge,  alwavs 
avoiding  the  use  of  excessive  force,  or  the  delicate  porcelain  edges  will 
shatter. 

A  later  sitting  is  required  for  a  final  finishing,  for  the  best  of  inlays  will 
need  smoothing  of  edges,  which  is  done  with  small  stones  or  sandpaper 
disks  and  strips. 

LOW  FUSING  PORCELAIN 

Having  described  the  process  of  making  an  inlay  with  the  platinum 
matrix  and  high  fusing  porcelain,  the  next  consideration  will  be  the 
modifications  necessary  when  low  fusing  porcelain  is  melted  into  a  gold 
matrix,  therefore  the  method  as  described  by  Dr.  J.  Leon  Williams^  is 
herein  inserted,  and  is  as  follows : 

"The  thinner  the  gold  can  be  used  the  more  perfect  the  fit  of  the 
finished  inlay.  A  proper  set  of  instruments  for  shaping  the  gold  form 
and  for  manipulating  the  porcelain  paste  is  an  important  matter.  I 
have  devised  for  these  purposes  the  set  of  instruments  shown  in  P^ig. 
379.  They  are  all  double-end  instruments.  Nos.  1,  2,  3,  and  4  are  de- 
signed for  fitting  the  gold  form  to  the  cavity,  while  Nos.  5  and  6  are 
for  manipulating  the  porcelain  paste.  The  gold  should  be  cut  out  to 
represent  roughly  the  shape  of  the  orifice  of  the  cavity,  but  consider- 
ably larger.  Fig.  380  shows  the  proper  shape  for  such  a  cavity  as  is 
shown  in  Fig.  381  at  a.  It  will  greatly  facilitate  the  shaping  of  the  gold 
form  if  a  notch  be  cut  out  of  the  gold  as  shown  in  Fig.  380,  and  at  the 
same  time  decrease  the  chances  of  breaking  through  the  gold  in  forcing 
it  into  the  shape  of  the  cavity.  It  should  first  be  introduced  into  the 
cavity  without  annealing.  The  cut  edges  will  then  slide  over  each  other 
as  the  centre  of  the  gold  is  forced  to  the  bottom  of  the  cavity.  .  .  . 
Then,  with  the  cotton  or  spunk  tightly  packed  in  the  cavity,  take  instru- 
ment No.  2  and  most  carefully  burnish  the  gold  around  the  entire  edge 

1  Dental  Cosmos,  November,  1S99,  vol.  xli,  p.  1087. 
23 


354  RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

of  the  cavitv.     This  instrument  will  he  found  well  adapted  to  reach 
every  part  of  the  margin.     It  will  generally  be  found  best  to  hold  the 


Fig.  379 


LOW  Fl'SING  PORCELAIN 


355 


cotton-wool  back  a  little  from  the  margin  of  the  cavity  when  one  is 
burnishing,  with  an  instrument  held  in  the  left  hand,  and  with  this 
instrument  (preferably  a  ball  burnisher)  also  press  the  cotton-wool  well 
into  the  cavity.  This  holds  the  gold  form  well  in  place  and  prevents 
rocking  while  the  edges  are  being  burnished. 

"Most  operators  have  found  the  removal  and  imbedding  of  the  gold 
to  require  the  most  delicate  manipulation,  and  by  the  methods  heretofore 
described  one  is  never  cpiite  certain  whether  or  not  this  part  of  the 
operation  has  been  successfully  performed  until  the  inlay  has  been  com- 
pleted and  tried  in  place.  All  of  this  uncertainty  may  be  avoided  by  the 
following  procedure:  Slightly  warm  and  roll  up  in  the  fingers  a  small 
ball  or  pledget  of  hard  white  wax,  such  as  is  supplied  for  crown-work 
and  bridge-work.  The  ball  of  wax  should  be  just  a  litde  larger  than  is 
necessary  to  fill  the  cavity  completely;  that  is  to  say,  it  should  slightly 
project  over  the  margin  of  the  cavity  all  around.     The  wax  should  be 


Fig.  380 


Fig.  381 


Sheet  of  gold  or  platinuni,  notched  and  ready 
for  adaptation  to  cavity. 


Right  superior  central,  showing  two  large 
proximal  cavities  to  which  access  is  ob- 
tained by  cutting  freely  from  the  lingual 
walls:  a,  tooth  with  cavities  prepared;  6,  por- 
celain inlays  for  same;  c,  tooth  showing  lingual 
surface;  d,  labial  surface  after  cementing  of 
inlays. 


quite  stiff  when  introduced  into  the  gold  form  as  it  lies  in  the  cavity  of 
the  tooth.  Now  take  the  broad,  thin  burnisher,  shown  in  No.  4,  Fig. 
379,  and  press  the  ball  of  wax  firmly  into  place.  To  prevent  the  burn- 
isher from  sticking  to  the  wax,  it  should  first  be  dipped  into  French  chalk 
or  pulverized  soapstone.  In  such  cavities  as  are  shown  in  Fig.  381, 
at  a,  broad  polishing  tape,  dusted  with  French  chalk,  may  be  used  for 
pressing  the  wax  ball  into  place;  but  great  care  should  be  exercised  not 
to  pull  the  tape  the  least  in  one  direction  or  the  other,  as  one  would  do 
in  polishing  a  filling.  This  would  rock  the  gold  form  and  mar  the  fit. 
The  pull  should  be  steady  and  equable  from  both  ends  of  the  tape, 
the  object  being  to  press  the  wax  everywhere  firmly  over  the  edges  of  the 
cavity.  A  stream  of  cold  water  should  now  be  thrown  on  the  wax,  and 
then  the  wax  and  gold  form  should  be  quickly  removed.  If  this  part  of 
the  operation  is  done  with  ordinary  care,  the  finished  inlay  will  always 
be  found  to  fit  perfectly.    To  facilitate  the  quick  removal  of  the  form,  care 


350 


RESTORATJON  OF   TKKT/I   JiV  CI'JMI'JXTKD  INLAYS 


should  be  taken  to  j)revent  the  wax  <)verlaj)j)iiin;  the  ^'old  nnich  at  any 
point  outside  the  margin  of  the  cavity.  To  prevent  this  and  also  to 
assist  in  securing  proper  embedding  of  the  gold  matrix,  it  is  well  to  let 
the  margin  of  the  gold  project  as  much  as  j>()ssible  beyond  the  edges  of 
the  cavity. 

"The  matrix  may  now  be  embedded  without  the  slightest  fear  that 
its  shaj)e  will  be  changed.  For  embedding  material  I  use  plaster  and 
marble  dust.  When  the  investment  is  sufficiently  hard  the  wax  is  thor- 
oughly melted  out  with  a  stream  of  boiling  water.  The  investment  is 
then  dried  and  brought  to  a  full  red  heat  with  the  blowpipe.  It  is  then 
allowed  to  cool,  and  is  ready  for  packing.  Now,  the  first  step  in  the 
packing  of  the  porcelain  paste  is  the  all-important  one  to  prevent  the 
porcelain  shrinking  away  from  the  walls  of  the  matrix.  This  may  always 
be  accomplished  easily  with  porcelain  of  any  make  if  the  following 
instructions  are  carefully  observed:  Mix  the  porcelain  paste  to  the  con- 
sistence of  soft  putty,  and  with  the  upper  point  shown  in  No.  6,  Fig.  379, 


Fig.  382 


Fig.  383 


Showing  bicuspid  with  cavity  involviri!? 
proximal  and  grinding  surfaces:  a,  tooth 
with  cavity  prepared;  b,  porcelain  inlay;  c. 
inlay  cemented  in  place. 


Canine  tooth  showing  at  a,  large  cavity,  and 
at  b  and  c,  large  porcelain  inlay  restoring 
contour  of  tooth. 


place  a  ring  of  this  putty  around  the  entire  circumference  of  the  cavity 
leaving  the  centre  quite  free  or  empty.  In  melting  a  porcelain  paste  it 
naturally  shrinks  toward  the  largest  mass  of  its  own  body,  or  toward 
the  centre  of  the  mass.  If,  then,  this  centre  be  removed  we  should 
naturally  expect  the  mass  to  shrink  toward  the  circumference,  and  this 
is  precisely  what  happens  when  manipulated  as  directed.  The  matrix 
always  comes  out  from  the  first  baking  Avith  the  porcelain  everywhere 
firmly  melted  to  the  Avails  of  the  matrix.  Nor  will  it  start  from  this 
position  at  any  subsequent  baking  unless  it  is  very  much  overheated. 
"After  each  packing  of  the  porcelain  paste,  a  small  camel 's-hair  bru.sh 
with  a  fine  point  should  be  moistened  (this  is  best  done  by  drawing  it 
between  the  lips  after  the  manner  of  water-color  artists)  and  drawn 
around  the  margin  of  the  matrix  to  remove  all  overhanging  particles  of 
the  paste.  If  this  be  not  done,  the  margins  of  the  inlay  will  often  be 
found  ragged,  and  a  perfect  margin  is  the  most  essential  feature  of  a 
porcelain  inlay.     If  gum  water  be  used  for  mixing  the  paste,  it  will  be 


CEMENTS  AND  MANIPULATION  357 

found  necessary  to  remove  these  overhaiioinof  j)articles  with  f/reat  care, 
as  the  tendency  naturally  is  for  the  gum  water  to  cause  the  particles  of 
powdered  porcelain  to  stick  to  the  gold  or  platinum  margin  of  the 
matrix.  In  building  up  the  inlay  for  restoring  lost  corners  of  teeth  and 
for  general  contours  the  work  will  be  much  facilitated  if,  after  the  first 
baking  has  been  carried  through  as  above  described,  to  secure  perfect 
union  with  the  walls  of  the  matrix,  a  small  piece  of  solid  porcelain  be 
placed  at  the  point  representing  the  highest  point  of  the  contour  of  the 
inlay.  These  pieces  of  porcelain  may  be  made  by  crushing  old  porce- 
lain teeth  in  an  iron  mortar.  Care  should  be  taken  to  use  a  piece  small 
enough  so  that  the  outer  edge  will  not  show  through  when  the  inlay  is 
completed.  Corners  like  the  one  shown  in  Fig.  383  may  be  produced 
in  this  manner  without  much  difficulty." 

CEMENTS  AND  MANIPULATION 

What  cement  do  you  use?  is  an  ever  present  query  in  all  porcelain 
discussion,  for  when  there  is  a  failure  the  cement  is  generally  blamed  for 
it.  This  is  a  natural  deduction  when  it  is  considered  that  a  student  in 
porcelain  is  more  familiar  with  cement  than  with  other  parts  of  the 
operation,  and  if  there  is  a  failure  it  is  a  natural  supposition  that  it  is 
caused  by  poor  material.  A  cement  must  be  tenacious,  finely  ground, 
and  not  c{uick  setting,  and  of  a  quality  most  likely  to  resist  moisture 
when  setting,  for  it  is  not  always  possible  to  keep  the  work  free  from 
dampness  during  that  important  stage.  There  are  many  cements  manu- 
factured that  have  these  requirements,  and,  like  other  materials  with 
similar  merits,  the  choice  rests  with  the  operator.  They  all  have  the 
same  disadvantage,  viz.,  opacity,  and  the  perfect  porcelain  operation 
cannot  be  claimed  until  the  attaching  medium  is  transparent,  or 
nearly  so.  The  newer  silicate  cements  were  thought  to  have  this  virtue, 
and  many  were  deceived  into  using  them,  but  it  was  found  that  the 
tenacious  period  was  of  short  duration  and  the  inlays  loosened,  causing 
much  disappointment.  A  common  trouble  is  mixing  cement  too  thick, 
thus  preventing  proper  seating  of  inlay,  which  makes  the  joint  con- 
spicuous and  unfinished.  When  this  occurs  quickly  remove  and  cleanse 
every  part  thoroughly,  replacing  with  a  thinner  mixed  material. 

Shading. — This  part  of  making  porcelain  inlays  is  the  most  difficult 
to  the  majority,  and  is  an  uncertainty  with  all  of  us.  The  problem 
of  shrinkage  is  an  unknown  quantity,  and  its  remedy  is  purely  mechan- 
ical, but  the  problem  of  shading  is  a  combination  of  various  consider- 
ations which  may  be  followed  most  minutely  and  then  the  object  may  be 
defeated  by  some  detail  not  always  possible  to  avoid,  and  this  most 
common  defect  is  caused  by  the  opaque  cements.  The  most  experi- 
enced have  this  discouragement,  but  it  can  be  decreased  by  using  a 
variety  of  shades  and  matching  carefully.     We  have  and  can  mix  an 


358  RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

almost  cikIIcs.s  variety  of  porcelain  shades,  hut  this  is  only  a  part  of  the 
re(|uirenieiit,  for  position  and  tooth  density  must  also  be  considered, 
together  with  (|uantity  or  si/.e  of  j)orcelain  to  he  fused.  There  is  also 
the  additional  difficulty  of  correct  fusing  to  reproduce  the  desired  shade. 

Overfusing  is  the  cause  of  more  shade  failures  than  any  other,  but 
practice  will  largely  obviate  this  trouble  as  in  other  difficulties.  The 
most  careful  directions  are  inadequate  as  compared  with  actual  demon- 
strations. When  the  best  has  been  said,  there  is  still  the  impossibility 
of  reaching  all  understandings,  because  this  part  of  the  subject  appeals 
directlv  to  the  artistic  sense,  and  can  only  be  comprehended  through 
observation  and  experience. 

The  difficulty  of  obtaining  colors  that  accurately  match  the  natural 
teeth  is  a  part  of  inlay  work  which  will  always  be  perplexing,  for  the 
teeth  are  largely  composed  of  organic  matter,  while  the  material  used  for 
repair  is  an  inorganic  composition,  differing  in  texture  and  density.  When 
selecting  the  colors  for  inlays,  note  the  various  shades  of  the  natural 
tooth,  for  frequently  there  are  three  or  more.  If  the  tooth  is  vital 
these  hues  have  a  distinction  which  is  lost  after  devitalization,  thus 
increasing  the  difficulties  of  matching  but  if  the  variant  and  uncertain 
hues  of  the  pulpless  tooth  are  once  reproduced  in  an  inlay,  the  subse- 
fjuent  change  attending  the  cementation  is  not  so  marked  because  of  the 
pulpless  tooth  opacity. 

Position  of  the  inlay  is  a  factor  which  largely  governs  the  shade,  for 
the  shadow  problem  is  an  incident  which  forces  consideration  also. 
This  is  particularly  evident  in  proximal  cavities,  and  is  remedied  to  some 
extent  by  making  the  inlay  a  shade  lighter,  and  is  also  controlled  by  the 
size  of  the  inlay.  A  lateral  incisor  being  much  smaller  than  a  cuspid 
must  be  treated  accordingly,  for  the  density  of  the  latter  is  much  greater 
and  will  allow  a  deeper  shade.  Labial  inlays,  particularly  bordering 
the  gingival  line,  can  safely  be  made  a  shade  deeper;  but  due  con- 
sideration must  be  given  to  depth,  for  if  very  shallow^,  the  porcelain 
should  be  of  greater  density  and  thus  overcome  the  cement  change. 
Inlays  of  this  kind  are  improved  in  texture  by  using  nearly  all  base 
body,  and  in  some  instances  low  fusing  porcelain  is  more  effective 
because  of  its  less  translucency. 

With  one  exception  all  inlay  porcelains  are  of  the  same  texture 
from  base  to  finish,  which  is  an  advantage  in  the  instance  just  cited, 
but  the- introduction  of  a  combination  consisting  of  a  basal  body  to  be 
covered  by  enamels  was  a  step  toward  procuring  more  natural  results 
in  the  majority  of  cases.  This  basal  body  represents  the  dentin,  which 
in  turn  is  covered  by  a  more  transparent  material  representing  the 
enamel,  thus  enabling  the  operator  to  blend  the  various  hues  of  shade 
of  which  the  natural  tooth  is  composed,  thereby  producing  a  trans- 
lucent effect  not  possible  by  one  dense  porcelain  no  matter  how  expert 
the  operator  may  be. 


CEMENTS  AND  MANIPULATION  359 

The  restoration  of  an  incisal  tip  or  corner  is  an  operation  that  recjuires 
much  practice  and  artistic  skill,  for  its  prominence  demands  perfect 
shading  and  adaptation.  An  operation  of  this  character,  while  testing 
the  ability  to  shade,  has  the  advantage  of  not  being  affected  by  the 
cement  line  because  of  greater  proportion  or  volume  of  porcelain. 
However,  perfection  must  not  be  expected  because  there  is  always  the 
diti'erence  between  the  natural  translucency  of  tooth  structure  and  the 
unavoidable  density  of  porcelain  which  in  certain  pcjsitions  is  more 
noticeable  by  the  deflection  of  light  rays. 

A  common  mistake  in  shading  is  in  not  considering  the  difference 
between  the  volume  of  shade  exposed  on  the  porcelain  shade  guide  and 
the  quantity  required  to  fill  the  cavity. 

The  mixing  of  several  shades  to  gain  the  one  desired  is  largely  one  of 
intuition,  because  that  shade  cannot  be  known  until  properly  fused. 
This  difficulty  is  unfortunate,  but  cannot  be  avoided,  as  all  porcelain 
powders  are  practically  the  same,  with  the  exception  of  a  few  extreme 
shades,  and  herein  lies  the  difference  between  the  porcelain  artist  and 
the  painter  whose  pigments  are  mixed  and  the  desired  shade  revealed 
to  the  eye  by  simple  manipulation. 

Fusing. — It  is  generally  conceded  that  fusing  porcelain  is  one  of  the 
greatest  difficulties  that  must  be  overcome  before  the  novice  can  feel 
that  he  has  made  any  advancement  toward  the  successful  making  of  an 
inlay  or  anything  in  which  porcelain  is  the  component  part.  It  is  an 
indisputable  fact  that  this  part  of  the  work  is  a  veritable  stumbling 
block,  and  the  cause  of  much  discouragement  which  is  only  overcome 
by  persistent  practice,  for  without  this  necessary  knowledge  successful 
results  are  not  possible. 

Porcelain  may  have  a  fusing  point  as  low  as  1600°  F.,  and  varving 
to  2600°  F.  or  even  higher,  therefore  the  operator  must  become  familiar 
with  these  varied  heats  and  their  productions.  This  will  mean  contin- 
uous applications  and  training  the  eye  to  the  various  stages  and  changes 
of  the  material.  Using  a  timepiece  with  a  pyrometer  will  be  of  great 
assistance,  but  the  personal  equation  is  always  the  dominant  factor,  and 
herein  lies  the  difficulty  of  giving  directions  that  will  be  accurate 
under  all  conditions.  Before  the  advent  of  the  pyrometer  the  eye  was 
the  only  test  of  heat,  therefore  to  the  beginner  this  device  has  consid- 
erable value,  together  with  the  fact  that  the  fusing  point  of  the  numerous 
porcelains  is  known.  Thus  a  certain  time  by  the  watch  with  the  fusing 
point  of  the  porcelain  already  known  and  the  pyrometer  showing  the 
temperature,  the  fusing  of  porcelain  seems  comparatively  easy.  Various 
sizes  of  porcelain  require  different  heats,  therefore  it  is  absolutely  neces- 
sary to  know  porcelain  in  all  its  changes,  without  any  assistance  what- 
ever, otherwise  the  work  will  be  either  over-  or  underfused,  and  only  by 
chance  will  it  be  correct  if  the  machines  are  depended  upon  entirely. 
There  can  be  no  difference  of  opinion  on  this  fact,  therefore  the  best 


;5()0         RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

CfiuipnuMit  is  the  jx-rsoiial  know  l('(lii;e  which  makes  one  independent 
of  aiiv  aj)|)liance  or  set  of  rides  and  regulations.  It  is  generally  con- 
tended tiiat  exposing  the  eye  to  such  severe  changes  ol  light  is  injurious, 
and  this  niav  he  true  beyond  a  certain  point,  viz.,  2300°  F.,  a  tempera- 
ture sufficient  for  the  majority  of  our  porcelains.  There  is  a  j)ro(Iuct 
l)V  a  well-known  firm  which  requires  a  heat  of  2600°  F.,  and  there  is 
no  doubt  that  the  eyes  should  be  protected  fn^m  the  glare  of  this  heat, 
which  is  unnecessarily  high,  especially  for  inlay  work. 

As  electric  furnaces  are  most  commonly  used  for  fusing  porcelain, 
it  is  not  very  difficult  for  the  student  to  become  familiar  with  the  various 
changes  of  heat  as  regulated  l)y  the  rheostat,  and  thereby  know  what 
step  will  fuse  a  certain  known  product.  For  instance,  the  first  step 
on  the  majority  of  furnaces  will  fuse  a  low  fusing  body  of  1600°  F.  in 
probably  one  minute  or  even  less,  but  the  same  heat  will  fuse  a  much 
higher  porcelain  if  given  longer  time.  Then,  again,  voltage  nuist  be 
considered,  for  in  many  cases  it  is  only  approximate,  sometimes  vary- 
ing three  or  four  points  less  or  that  much  more,  and  still  coming  under 
the  class  of  110  volts  direct.  This  fact  is  particularly  noticeable  in  local 
estal)lishments  such  as  office  buildings.  The  alternating  current  is  usually 
more  even,  and  that  of  220  however  bemg  very  strong  and  harder  on  the 
furnace  muffles. 

The  best  fusing  is  obtained  by  inserting  the  porcelain  at  the  lowest 
temperature  and  gradually  and  slowly  raising  the  heat  until  the 
fusing  point  is  obtained,  thus  passing  the  material  through  its  various 
stages  of  condensation.  These  stages  are  called  "biscuiting,"  and  a 
porcelain  partially  fused  may  be  called  a  medium  or  hard  biscuit.  In 
the  latter  condition  the  porcelain  has  a  half  glaze  and  has  shrunk  to  a 
solid  mass  and  is  ready  for  the  additional  material  recjuired  to  give  form. 
Then  the  porcelain  can  be  fired  until  it  has  the  finished  gloss,  which  is 
determined  by  the  eye  of  the  manipulator.  The  best  results  are  always 
obtained  by  underf using  the  first  bake,  because  several  high  heats  will 
overfuse  the  groundwork  which  reduces  its  strength  and  solidity.  Using 
a  porcelain  of  slightly  lower  fusing  point  the  finishing  will  obviate  this 
tend'ency,  which  is  detrimental  to  the  whole  work. 

As  an  instance  of  this,  note  a  manufactured  tooth  which  is  finishenl 
in  one  baking,  and  the  same  directions  are  applicable  to  carved  teeth 
for  special  cases.  A  student  will  readily  learn  what  is  a  proper  glaze 
re(juired  if  he  will  take  any  plain  or  plate  tooth  and  apply  porcelain  to 
its  surface  and  watch  the  various  changes  until  liis  material  has  reached 
the  same  condition.  This  simple  experiment  will  also  help  him  to 
recognize  the  heat  required  for  these  changes  and  ultimately  enable 
him  to  acquire  self-confidence  in  the  management  of  the  fusing  process. 

Porcelain. — Porcelain  bodies  made  for  inlay  purposes  are  to  be  had 
in  great  varietv,  both  in  fusinfj  point  and  texture;  in  fact,  there  is  such  a 
number  for  choice  that  the  unexperienced  must  necessarily  be  bewildered; 


CEMENTS  AND  MANIPULATION  3G1 

however,  this  difficulty  will  settle  itself  like  many  others  that  may  at 
one  time  have  been  just  as  perplexing. 

For  many  years  there  was  much  controversy  regarding  the  qualities 
of  various  products,  particularly  between  the  advocates  of  a  high  heat 
porcelain  and  those  of  low  fusing  qualities.  While  this  (juestion  is  still 
debatable,  it  is  an  indisputable  fact  that  in  America  porcelains  of  the 
higher  grade  have  the  preference.  This  may  be  from  the  fact  that 
the  manufacturers  of  artificial  teeth  in  this  country  have  always  used  a 
high  fusing  material,  and  as  the  product  has  stood  the  test  of  time  it  is 
only  natural  to  apply  this  argument  to  the  inlay  question. 

English  tooth  body  fuses  about  400°  F.  lower  than  the  highest  fusing 
American  body,  which  places  the  English  on  our  list  as  a  medium  fusing 
material,  and  its  excellent  quality  is  indisputable;  in  fact,  the  majority  of 
our  inlay  bodies  are  really  a  medium  heat,  ranging  from  2150°  F.  to 
2300°  F.,  therefore  the  difference  between  this  fusing  degree  and  that 
of  low  body  of  1600°  F.  or  thereabouts  is  the  point  of  argument. 

When  porcelain  inlays  were  introduced  the  standard  material  was 
the  continuous  gum  bodies  then  well  known  to  porcelain  workers  and 
put  on  the  market  for  their  use.  It  was  the  only  material  to  be  had,  and 
while  it  possessed  the  required  quality,  it  had  no  variety  of  shade. 
After  some  years  this  was  remedied,  and  the  advent  of  the  pyrometer 
enabled  us  to  learn  the  approximate  fusing  temperatures  of  the  old 
continuous  gum  bodies  which  were  found  to  be  about  2300°  F.  These 
bodies  have  not  been  much  improved  upon  either  in  quality  or  finish. 
The  first  low  fusing  material  was  introduced  in  1892  by  Dr.  Downie, 
but  was  not  satisfactory  for  inlay  work  because  of  its  poor  shades, 
although  it  was  quite  extensively  used  for  crowns.  A  few  years  later 
Ash  &  Sons  made  up  a  small  assortment  much  improved  in  shades. 
Dr.  Jenkins  introduced  his  low  fusing  enamel  in  1898.  After  this 
date  manufacturers  of  porcelain  produced  an  assortment  suitable  to 
all  circumstances. 

The  wearing  qualities  of  various  porcelains  are  practically  equal  in 
certain  positions,  notably  in  cavities  not  extending  to  incisal  edges  or 
masticating  surfaces,  and  in  shallow  labial  cavities.  Low  fusing  porcelain 
has  an  advantage  from  the  fact  that  its  opacity  prevents  the  cement 
from  changing  the  shade,  which  is  frequently  the  case  with  a  high 
fusing  and  more  translucent  body. 

W^orkers  of  higher  fusing  porcelain  will  be  more  or  less  conversant 
with  all  porcelains  and  their  variations,  because  this  field  is  greater 
and  has  practically  no  limitation;  but  a  low  fusing  porcelain  worker  is 
usually  at  sea  if  not  using  that  material,  while  anyone  accustomed  to 
the  higher  heats  can  fuse  the  lower,  providing  care  is  used  not  to 
overheat.  Too  much  heat  is  fatal  to  low  fusing  body,  as  it  means  not 
only  loss  of  shade,  but  also  loss  of  strength.  The  same  rule  applies  to 
all  porcelains,  but  not  to  the  same  extent  if  the  porcelain  is  high  fusing, 


362  RESTORATIOX  OF   TEETH   RY  CEMEXTED  IXLAYS 

for  its  working  latitude  is  much  greater.  Low  fusing  material  is  usually 
moulded  in  a  gold  matrix  which  is  invested.  Platinum  must  be  used 
as  the  matrix  for  iiighcr  iicat  porcelains,  and  no  investment  of  it  is 
necessary. 

As  pyrometers  are  commonly  used,  a  few  of  the  most  popular  bodies, 
and  approximate  fusing  points  will  assist  the  student,  bearing  in  mind 
that  these  figures  are  based  on  two-minute  tests,  with  conditions  favor- 
able for  accuracy. 

Low  fusing.  Medium  fusing. 

Ash  &  Sons,  1550°  F.  Brewster's  Enamel,  20X0°  F. 

Jenkins,  1550°  F.  8.  S.  White's  Medium,  2100°  F. 

Downie's,  1550°  F.  .\sh  &  Sons'  "  High,"  1900°  F. 
Brewster's  Gold  Matri.x,  1800°  F. 

High  fusing. 
S.  S.  White's  Inlay,  2300°  F. 
Close's  Continuous  Gum,  2300°  F. 
Whiteley's  Inlay,  2200°  F. 
Wliiteley's  Inlay  special,  2400°  F. 
Brewster's  Foundation,  2200°  F. 
Consolidated  Inlay,  2600°  F. 
.lohnson  &  Lund's,  2500°  F. 

Furnaces. — The  advancement  in  the  matter  of  furnaces  has  been  so 
rapid  that  less  than  thirty  years  ago  the  user  of  porcelain  depended 
on  such  an  apparently  crude  appliance  as  is  shown  in  Fig.  384  (old 
coke  furnace),  and  yet  the  beautiful  porcelain  dentures  and  carved 
work  of  the  older  dentists  has  not  been  surpassed. 

It  was  early  recognized  that  a  small,  quick  heating  appliance  was  a 
necessity,  and  this  difficulty  was  solved  by  Dr.  C.  H.  Land  by  inventing 
the  first  gas  furnace  in  1886.  This  machine,  while  a  great  improvement, 
was  slow  and  tiresome,  as  the  constant  use  of  bellows  w^as  necessary  for 
half  an  hour  before  the  furnace  was  hot  enough  for  use.  A  smaller 
and  quicker  gas  furnace  succeeded  this,  more  applicable  for  inlays  and 
crowns,  and  was  successfully  used  until  super.seded  by  electrical  outfits, 
which  have  the  advantage  of  cleanliness,  purity,  and  noiselessness. 

A  gas  fiu'nace  is  noisy  and  gives  much  trouble  in  carbonizing  the 
porcelain,  or  as  it  is  usually  termed  "gassing."  Fortunately,  that  is  a 
discouragement  of  the  past,  for  electricity  has  reduced  fusing  cares  to 
the  mininunn.  Other  furnaces  of  that  time  were  the  Parker-Stoddard, 
Downie,  and  Fletcher. 

Dr.  L.  E.  Custer  invented  the  first  electric  furnace  in  1894,  and  while 
it  was  a  distinct  improvement,  there  was  much  trouble  in  muffle  wires 
burning  out,  which  caused  much  delay  and  retarded  the  general  use  of 
this  class  of  furnace.  The  Custer  electric  furnace  as  now  perfected 
is  practically  useful,  and  is  a  strong  favorite.  Five  years  later  the  Ham- 
mond (Fig.  385)  was  patented,  and  immediately  became  popular  from 
the  fact  that  a  "damaged"  muffle  could  be  replaced  immediately. 


CEMENTS  AND  MANIPULATION 


363 


This  furnace  has  remained  a  favorite  until  the  present  time,  but  is 
beino-  gradually  replaced  by  the  S.  S.  White  Co.'s  new  furnace  (Fig.  380), 


Fin.  385 


Old  style  coke  furnace. 


The  Hammond  furnace  No.  1 . 


Fig.  386 


S.  S.  "White  furnace  -with  pyrometer  attachment. 


3()4 


Rh'STOh'ATIOX   OF   TKh'T/I   JiV  CEMENTED  IXLAYS 


which  is  .similar,  hut  improved  in  (('rtiiiii  (ictails,  ami  it  is  also  arranged 
with  pyroiiu'tor  attachinciit. 

In  1!K)2  tlu'  Peiton  appeared.  liesides  these  furnaces  there  are  sev- 
eral others  distinct  in  form,  and  all,  with  few  exceptions,  liave  a  pyrom- 
eter attachment.  They  aic:  the  Fletcher,  Peck,  (lerhardt,  and  Koach, 
anil  otluM's  inclndinf,^  the  Price,  which  has  been  withdrawn,  although 
Dr.  Price  was  the  first  to  apply  the  pyrometer. 

In  addition,  furnaces  are  sKso  made  for  gasoline  use.  The  ])rincipal 
types  are  the  Turner  and  Brophy.  They  are  of  great  value  to  the  out-of- 
town  dentist,  because  they  not  only  fuse  porcelain,  hut  have  ec|ual  facility 
in  blowpipe  work  and  metal  heating,  thus  enabling  those  not  po.sse.s- 
sing  gas  or  electricity  to  be  practically  on  the  same  footing  with  the  city 
practitioner. 

GOLD  INLAYS 

Gold  Matrix  Inlays,  (lold  matrix  inlays  have  been  used  to  advantage 
for  many  years,  i)ut  the  casting  process  has  largely  suj)plante<l  this  pro- 
ce.s.s,  therefore  a  description  of  these  difhcult  and  extensive  operations 
must  be  considered  unneces.sary  in  this  day  of  later  improvements.  It 
is  an  erroneous  idea,  largely  prevalent  in  the  ])rofession,   that  matrix 


Fio.  387 


Fig.  388 


Fio.  389 


C.ivitios  and  rf.itor.ativoa  suit.-ihlo  for  ami  illuslratiriK  the  cold  matrix  inlay  molhod. 


gold  inlays  are  entirely  out  of  date,  for  there  is  no  doul)t  of  tliis  work 
still  having  its  place  and  that  it  is  applicable  and  successful  under 
certain  circumstances.  Its  chief  recommendation  is  the  .saving  of  much 
valuable  time.  One  predominant  rea.son  why  the  matrix  inlav  does  not 
api)eal  to  the  general  dentist  is  that  pha.se  of  the  operation  which  is  the 
first  con.sideration,  viz.,  the  making  of  a  matrix.    Having  that  knowledge, 


CEMI'JNTS  A.VD  MANIPULATION  3G5 

the  rest  of  tlie  operation  is  so  simple  that  verv  Httle  prac-tice  will  accom- 
plish most  satisfactory  results. 

Vie.  300  I'lu.  301  Fk;.  392 


The  process  of  making  gold  inlays  is  recommended  for  use  in  various 
positions  where  much  contouring  is  not  required,  such  as  proximal 
cavities  in    bicuspids    and    molars,   extending    slightly  between  cusps. 

Fig.  393  Fig.  394  Fig.  395 


Ca^-ities  and  restoratives  suitable  for  and  illui^trating  the  gold  matrix  inlay  method. 

Occlusal  surfaces  between  cusps,  shown  in  Fig.  3S7,  buccal  cavities  on 
same  teeth  (Figs.  388,  389,  and  390);  and  small  corners  and  incisal  tips 
on  anterior  teeth  which  preclude  the  use  of  porcelain  (Figs.  391  to  395). 


:m\ 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 


Fig.  396 


In  (lu'sc  |;itt(>r  j)()siti()ns  the  proof  of  the  a(Ivanta<j;e  of  this  work  is  the 
faet  of  the  success  of  the  method  when  every  other  material  had  been 
tried  and  faiknl  aftir  sliort  use.  An  expert  ^old  operator  may  not  treat 
this  assertion  seriously,  believing-  that  a  haninicred  oold  fillino-  will  he 
equally  successful. 

Ill  manv  cases,  particularly  in  hard  structured  teeth,  this  is  quite 
possible,  but  in  frail  teeth  the  apj)lication  of  this  kind  of  inlay  is  simple, 
safe,  and  satisfactory,  and  saves  time. 

The  procedure  for  this  work  is  to  make  a  matrix  of  the  cavities  as  for 
porcelain,  eithiM-  in  platinum  of  the  same  <i:au<je  or  oojd  of  No.  30  foil, 
with  the  dill'(M'(Mice  that  as  the  matrix  will  remain  part  of  the  hllinfj^,  it  is 
not  necessary  to  burnish  or  stretch  the  foil  to  position.  It  may  be 
carried  to  the  bottom  and  walls  with  no  attention  to  folds  or  creases,  but 
the  edoes  must  be  well  defined,  as  in  porcelain  work.  When  the  matrix 
is  made  and  while  still  in  the  cavity,  matt  or  sponge  gold  of  any  descrip- 
tion is  loosely  packed  into  it  and  in  sufficient  (|uantity  to  support  the 
walls  and  cover  the  floor  and  the  break  in  the  matrix  which  is  then 
removed  and  two  or  three  small  pieces  of  22  k  solder  applied  to  the 
soft  gold  and  meltc-d  with  the  blowpipe  (Fig.  390).  The  solder  will  run 
into  the  gold  to  the  matrix  walls,  thus  making  the 
whole  piece  rigid.  The  excess  matrix  may  be  re- 
moved if  so  desired  and  replaced  in  the  cavity  and 
thoroughly  burnished;  it  is  again  removed  and  with 
a  fine  pencil  l)rush  licjuid  rouge  is  traced  over  the 
whole  outer  surface  to  the  cavity  margin.  This 
must  be  carefully  done,  for  the  slightest  irregularity 
of  the  outline  will  be  reproduced  by  the  gold.  The 
tracing  of  the  lifjuid  rouge  prevents  the  gold  from 
flowing  bevond  the  margins,  therefore  it  is  a  good  rule  to  coat  the 
underside,  particularly  if  the  matrix  is  of  gold  foil.  Small  pieces  of 
solder,  or  pure  gold  if  so  desired,  are  then  dropped  in  connection  with 
the  cavity  and  melted  with  the  blowpipe.  After  the  desired  form  is 
secured  the  excess  matrix  is  cut  away  and  the  inlay  is  ready  for 
treatment,  as  already  described  into  casting  process. 

Kowan's  decimal  gold  No.  30  for  packing  the  matrix  has  an  advan- 
tage over  matt  gold  because  it  is  composed  of  a  thin  layer  of  platinum 
between  two  layers  of  gold,  therefore  it  is  only  necessary  to  throw  the 
flame  on  this  combination  while  it  is  in  the  matrix  and  the  gold  portion 
immediately  acts  as  a  .solder  which  unites  the  whole  without  any  addi- 
tional .solder.  This  combination  should  be  used  only  with  a  platinum 
matrix,  and  in  any  ca.se  the  rouge  should  not  be  applied  until  after  a 
trial  fltting,  because  the  burnishing  will  carry  the  tracing  from  the  edges 
to  the  interior  and  prevent  the  solder  flowing  easily. 

Cleanliness  and  care  will  obviate  much  trouble,  for  gold  will  not 
flow  where  there  is  the  slightest  deposit  of  rouge.    Small  tips  and  cor- 


>^.JS^K 


CEMENTS  AND  MANIPULATION  3G7 

ners  are  contoiiretl  by  the  use  of  small  pieces  of  (:!jold  plate  cut  to 
desired  shape  or  melted  into  small  globules,  which  extends  the  contour; 
these  are  afterward  ground  to  shape.  A  little  practice  will  insure  very 
satisfactory  results. 

The  Cast  Grold  Inlay. — There  have  been  many  inventions  in  dentistry, 
but  it  is  doubtful  if  any  improvement  was  ever  received  with  greater 
enthusiasm  than  that  of  the  inlav  casting  method. 

Dr.  "Wm.  H.  Taggart,  of  Chicago,  has  the  distinct  honor  of  being 
the  inventor  of  the  first  appHance  for  this  purpose,  having  demon- 
strated its  possibiHties  before  a  meeting  of  the  First  District  of  New 
York,  in  January,  1907. 

For  twenty  years  the  profession  had  been  gradually  accepting  the 
inlay  in  its  various  forms,  also  the  fact  that  a  cemented  filling  had  merits 
worthy  of  consideration,  therefore  this  newer  and  more  perfect  process 
was  received  without  reservation,  with  the  i-esult  that  almost  every  den- 
tist is  a  practitioner  of  this  method.  The  almost  unlimited  possibilities 
of  the  casting  process  has  developed  newer  operations  almost  too  numer- 
ous to  mention,  including  inlays  of  all  forms,  crowns,  and  various  bases 
for  such  work,  cast  bridges,  partial  and  full  plates,  dental  splints,  and 
various  appliances.  In  fact,  the  ingenious  dentist  has  by  no  means 
exhausted  its  possibilities  of  practical  application. 

The  machines  for  performing  this  work  have  rapidly  multiplied  in 
design,  and  they  are  made  in  such  variety  of  form  and  cost  that  no  one 
need  be  dissatisfied. 

Casting  molten  gold  in  various  forms  can  be  done  in  a  myriad  of  ways, 
but  the  basal  technique  is  the  same  in  all  instances,  therefore  the  de- 
scription as  given  by  Dr.  Taggart  is  necessarily  authoritative,  and  is  as 
follows ;! 

"  In  all  my  casting  work,  whether  operative  or  prosthetic,  I  am  using 
a  special  wax  known  as  'Taggart's  Green  Wax,'  This  wax  has  been 
made  green  in  color  because  it  will  thus  be  easy  to  dift'erentiate  between 
the  wax,  the  enamel,  and  the  gum  tissue  when  working  directly  in  the 
cavity;  and  while  most  excellent  results  may  be  obtained  by  taking 
impressions  and  making  amalgam  or  cement  replica  models  of  cavities, 
manifestly  no  duplicate  of  the  cavity,  and  no  articulated  model  thereof, 
can  be  so  accurate  as  the  cavity  itself  and  the  patient's  jaws,  which  must 
give  the  exact  occlusion.  A  little  practice  will  convince  the  majority 
that  it  is  better  to  w^ork  within  the  mouth  when  making  inlays. 

"This  wax  is  warmed  in  water  not  above  138°  F.  until  it  is  thoroughly 
softened  throughout  the  mass.  It  must  not  be  w^armed  with  dry  heat, 
nor  manipulated  w4th  the  fingers,  with  the  idea  that  the  softening  can 
be  hastened  in  that  way.  A  piece  the  size  of  the  stick  and  of  length  in 
proportion  to  the  size  of  the  cavity  should  be  softened  and  carried  in  its 

>  Items  of  Interest,  April,  1908. 


368 


UKSrORATIDS'  OF  TEETH  BY  CEMENTED  INLAYS 


orij^inal  form  to  tlie  cavity,  and  firmly  pressed  into  the  cavity  vvitli  the 
finders,  allowing;  the  excess  to  act  as  a  piston  in  forcing  it  into  all  parts 
of  the  cavity.  The  patient  should  tiieii  close  the  jaw,  biting  firmly  into 
the  wax,  gi\ing  the  imprint  of  the  opposing  cusps.  Then  have  him 
move  the  jaws,  as  in  the  act  of  chewing  gum;  this  wears  .down  all  the 
high  j)oints  and  gi\'es  the  correct  occlusal  form.  All  excess  wax  is 
trimmed  away  and  the  wax  carved  into  the  exact  form  desired  for  the 
completed  inlay.    A  special  quality  of  the  wax  is  that  it  can  l)e  beauti- 


fully carved,  remaining  hard  enough  for  this  purpose  even  at  the  temper- 
ature of  the  mouth;  and  as  the  process  exactly  reproduces  every  form 
and  line  of  the  wax  model,  and  as  wax  is  more  easily  carved  than  gold, 
it  will  repay  the  operator  to  spend  a  little  time,  care,  and  artistic  skill 
in  making  the  wax  model.  The  wax  inla>-  remains  hard  enough  in  the 
mouth  so  that  it  may  be  lifted  from  the  cavity  without  change  of  form, 
and  it  can  then  either  be  held  in  the  fingers  for  further  carving,  or 
artistic  touches  may  be  added  when  the  wax  inlay  is  mounted  on  the 
sprue,  as  in  Fig.  398. 


CEMENTS  AND  MANIPULATION 


309 


"When  finished  the  wax  inlay  is  held  in  tlie  left  hand  and  the  sprue 
wire  in  the  rij>ht.  'J'hen  heating  the  sprue  wire  until  it  will  melt  its  way 
into  the  wax,  the  two  are  brought  together,  as  shown  in  Fig.  399. 


Fui.  308 


Fig.  399 


"The  inlay  and  sprue  wire  are  then  placed  in  the  crucible  former,  as 
in  Fig.  398.    The  investment  is  properly  mixed  in  the  following  manner: 

"  The  large  cup  on  the  measuring  device  (Fig.  400)  is  to  be  filled  lightly 
with  investment  and  scraped  off  flush  with  a  straight-edged,  silver- 
plated  dinner  knife,  which  can  be  used  as  a  spatula. 


Fig.  400 


"The  small  end  of  the  measuring  device  (Fig.  400)  is  filled  even 
full  with  water  and  the  two  mixed  together.  For  the  large  flasks  just 
double  these  quantities.  Then  place  the  rubber  plaster  bowl  in  the 
position  shown  in  Fig.  401,  and  jar  it  on  the  bench,  rotating  it  slowly 


Fig.  401 


in  order  to  smear  the  whole  inside  of  the  bowl  with  a  thin  layer  of 
investment.      This  allows  all  air  easily  to  work  out  through  this  thin 
layer.     Carefully  place  the  investment  on  the  inlay  in  such  a  way  as 
24 


370         RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 


absolutely  to  avoid  all  air  hiihhles  being  caught  in  the  investment, 
because  these  air  spaces  would  be  filled  with  gold  in  the  casting. 

"This  stage  is  represented  by  ¥ig.  402.  Apply  the  flask,  round 
edge  down,  and  pour  the  investment  until  the  ring  is  full.  Do  not  jar 
the  in\cstment  to  make  it  go  to  place;  this  only  causes  the  contained 
air  in  the  investment  to  form  large  bubbles  against  the  wax.  Rotate 
the  flask  slightly  and  cover,  and  the  mass  will  settle;  then,  if  necessary, 
add  more  investment  and  turn  the  flask  over  on  to  some  smooth  surface 
and  ])ress  the  excess  to  i)lace,  allowing  the  excess  to  squeeze  out  of  the 
small  hole  in  the  flask.  The  investment  should  be  allowed  to  set  for  at 
least  fifteen  minutes,  or  it  can  be  set  aside  for  an  indefinite  period;  but 
better  results  are  obtained  by  drying  out  as  soon  as  the  plaster  has  set. 
When  ready  for  casting,  the  crucible  former  is  removed,  as  in  P^ig.  403, 
the  flask  is  set  over  the  Bunsen  flame,  and  at  first  slowly  dried  out;  as 
soon  as  the  steam  ceases  forming  a  higher  heat  can  be  turned  on  and  the 
wax  burned  thoroughly. 


Fig.  402 


Fig.  403 


"  It  is  now  ready  for  the  casting  machine,  and  a  generous  button  of 
24  k  gold,  at  least  five  pennyweights,  should  be  placed  in  the  crucible. 
As  there  is  no  waste  in  casting,  it  is  always  best  to  have  plenty  of  gold 
in  the  crucible. 

"Referring  to  Fig.  397,  the  machine  is  operated  in  the  following 
manner: 

"  The  flask  9  is  placed  in  ring  10.  The  city  gas  is  connected  by  hose  to 
12.  The  nitrous  oxid  blowpipe  8  is  turned  at  right  angles  to  the  machine 
and  the  city  gas  lighted,  making  a  smoky  flame  about  four  inches  long. 
The  handle  to  the  reducing  \ahe  3  is  turned  backward,  or  to  the  left ;  now 
open,  with  the  wheel,  the  main  nitrous  oxid  cylinder  valve  1.  This 
allows  the  high  pressure  of  the  nitrous  oxid  gas,  which  in  a  full  cylinder 
is  one  thousand  pounds,  to  pass  into  the  reducing  valve  3,  and  by 
turning  the  bar  handle  of  the  reducing  valve  3  to  the  right,  any  degree 
of  pressure  can  be  indicated  on  the  gauge,  although  five  to  eight  pounds 
is  sufficient.  The  needle  valve  21  is  opened  to  allow  nitrous  oxid  to 
flow  through  11  to  unite  with  the  city  gas,  which  comes  in  at  12.    By 


CEMENTS  AND  MANIPULATION  371 

mixing  the  proper  proportion  of  nitrous  oxid  with  the  city  gas  a  blue 
flame  is  made  about  three-cjuarters  of  an  inch  long.  Now  place  the  flask 
9  in  the  machine  ring  10,  using  the  tongs;  then  turn  the  blowpipe  to  the 
proper  position  to  play  on  the  button  of  gold,  and  when  the  gold  is  in 
a  boiling  state,  bring  the  handle  forward  with  a  decided  jerk,  which  will 
automatically  throw  the  blowpipe  8  out  of  the  way,  and  automatically 
bring  the  pressure  plate  7  down  airtight  on  the  flask  9,  and  automatically 
hold  the  lever  down  by  closing  the  lock  5,  and  automatically  start  the 
alarm  whistle  4,  which  is  regulated  as  to  its  volume  of  sound  by  the 
small  needle  valve  20.  The  object  of  this  alarm  is  to  draw  attention 
to  the  fact  that  the  main  valve  on  the  nitrous  oxid  cylinder  1  is  to  be 
shut  off  when  the  casting  is  finished,  or  the  nitrous  oxid  will  escape 
over  night.  The  sustained  pressure  should  be  kept  on  top  of  the  gold 
for  thirty  seconds,  after  which  the  flask  can  be  taken  out  and  put  into 
water,  when  the  investment  can  be  washed  off.  The  inlay  should  now 
be  placed  in  50  per  cent,  hot  hydrochloric  or  full  strength  hydrofluoric 
acid,  to  make  certain  that  all  foreign  investment  is  dissolved  off. 

"The  excess  gold  is  sawed  off  at  the  sprue  and  the  filling  mostly 
finished  out  of  the  mouth.  It  is  always  best  to  examine  the  cavity  side 
of  the  inlay  under  a  magnifying  glass  so  as  to  see  that  there  are  no  little 
beads  of  gold,  which  would  prevent  it  going  thoroughly  to  its  seat.  As 
these  fillings  fit  the  cavity  so  tightly,  it  is  best  to  drive  them  to  place 
several  times  with  a  stick  and  mallet  before  setting,  and  when  the  cement 
is  in  place,  seat  again  with  mallet  and  stick. 

"This  repeated  tapping  with  the  mallet  in  different  directions  will 
seat  an  inlay  better  than  it  can  possibly  be  done  by  direct  pressure  on  the 
inlay.  The  margins  can  now  be  gone  over  with  stones  and  disks  of 
polishing  tapes  and  finally  polished.  When  prosthetic  pieces  are  being 
made,  Taggart's  green  wax  should  be  kept  at  a  workable  temperature 
by  frequently  holding  the  model  and  wax  in  water  at  138°  F. 

"The  possibilities  for  displaying  ingenuity  in  constructing  different 
prosthetic  pieces  are  only  limited  by  the  versatility  of  the  dentist. 

"The  nitrous  oxid  blowpipe  for  this  work  has  decided  advantages 
over  any  other  blowpipe  flame,  for  the  reason  that  the  gold  can  be 
melted  so  much  more  readily,  and  brought  into  a  more  fluid  condition 
and  shot  into  the  mould  while  the  mould  Is  practically  cold,  and  not  unduly 
expanded,  as  the  investment  would  be  if  the  gold  were  melted  by  the 
ordinary  blowpipe." 

In  a  further  communication  Dr.  Taggart  states:^ 

"Wax  and  its  Treatment.^ — To  be  scientifically  correct,  a  wax  must  be 
of  such  a  nature  as  to  be  sluggish  in  movement,  and  which,  at  the  tem- 
perature of  the  mouth,  will  absolutely  break  before  it  will  bend.  With- 
out this  quality  there  is  no  certainty  that  it  has  not  become  distorted, 
especially  in  complicated  cavities. 

*  Items  of  Interest,  July,  1911. 


372         RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

"  With  srift  waxes  and  the  use  of  cold  water  it  is  possible  to  obtain 
fairly  good  results  in  ordinary  cavities,  but  where  there  are  any  com- 
plications, such  as  are  found  in  M.  O.  1),  (mesial-occlusal-distal)  cavities, 
the  wax,  as  soon  as  the  cold  water  is  withdrawn,  almost  immediately 
resumes  the  temperature  of  the  mouth,  and  while  it  may  be  easily 
withdrawn  from  the  cavity,  there  is  no  telling  to  what  extent  it  may 
ha\e  been  bent,  and  this  condition  will  not  give  a  high  percentage  of 
successes  in  the  places  which  should  be  the  most  accurately  filled. 

"  I  have  mafle  eleven  hundred  and  fifty  different  mixtures  of  waxes 
and  gums  and  did  not  succeed  in  having  continuously  successful  results 
until  a  wax  was  obtained  which  possessed  the  foregoing  properties,  but 
others  seemed  to  think  it  required  too  much  effort  to  get  it  to  a  workable 
condition.  From  the  start  it  was  found  that  the  uniform  plasticity 
throughout  the  whole  mass  could  best  be  obtained  by  warming  in  hot 
water,  but  in  trying  to  do  this  in  a  hurry  the  surface  was  made  softer 
than  the  internal  mass;  yet  if  sufficient  time  were  used  to  allow  the 
whole  mass  to  be  thoroughly  heated  throughout,  excellent  results  were 
obtained.  To  surmount  the  problem  of  heating  the  wax  properly,  I  have 
devised  an  automatic  electric  heater  (Fig.  404).  When  the  instrument 
is  set  to  work  so  as  to  give  the  proper  degree  of  plasticity,  it  will  always 
duplicate  this  temperature,  but  it  must  be  allowed  time  to  arrive  at 
this  correct  temperature,  and  by  making  it  automatic  this  can  be  accom- 
plished to  a  nicety.  As  soon  as  I  commence  to  prepare  the  cavity,  the 
heater  is  started,  and  this  gi\'es  ample  time  for  the  wax  to  be  thoroughly 
warmed  throughout  its  mass,  so  that  when  the  ca\'ity  is  finished  the 
wax  is  ready  to  be  used,  without  loss  of  time,  with  annoying  conditions 
removed,  and  with  continuously  duplicated  and  gratifying  results.  This 
instrument  has  brought  the  moulding  of  the  wax  pattern  down  to 
practically  a  scientific  basis. 

"This  instrument  (Fig.  404)  has  as  a  heating  element  a  16-candle-power 
lamp,  ^^^th  a  carbon  filament.  The  carbon  filament  is  being  abandoned 
for  lighting  purposes,  because  it  furnishes  more  heat  than  light.  The 
Tungsten  filament  furnishes  more  light  than  it  does  heat.  For  that 
reason  I  have  used  the  carbon  filament  to  furnish  the  heat. 

"It  works  on  the  following  principle:  There  is  a  glass  disk,  which 
can  be  turned  to  one  side  in  order  to  place  the  wax  on  it.  As  all  the 
heat  comes  from  one  direction,  a  flat  metal  disk  or  surface  would  receive 
heat  upon  its  upper  surface,  and  the  under  surface  of  the  wax  would  be 
cool.  I  found  that  one  of  these  disk  glasses  is  thin  enough  so  that  as 
the  heat  strikes  it,  it  is  reflected  back  so  that  the  under  side  of  the  wax 
is  warmed  as  well  as  the  upper.  I  have  had  wax  in  the  instrument 
for  fifty-six  hours  at  a  time,  and  when  I  examined  it  it  was  plastic  in 
Its  mass,  and  no  more  heated  on  the  upper  than  on  the  lower  side. 

"The  electric  heating  apparatus  was  hard  to  control  automatically 
if  the  current  were  allowed  to  go  in  a  continuous  path,  but  by  adopting 


CEMENTS  AND  MANIPULATION 


373 


the  principle  I  have  used,  of  havin<:j  the  heat  all  on  or  all  off,  it  permits 
the  intermittent  heating  of  a  thermostat.  It  heats  the  thermostat, 
which,  as  soon  as  it  gets  a  little  too  warm,  breaks  the  electric  circuit. 
When  the  electric  circuit  is  broken  the  thermostat  begins  to  cool  down, 
and  the  thermostat  throws  the  current  into  the  lamj)  again.  It  works 
bv  excessive  heat,  and  it  shows  there  is  not  a  one-hundredth  degree  of 


Fig.  404 


difference  in  temperature  between  the  surface  on  one  side  or  the  other. 
Sometimes  it  will  flash  50  or  60  times  in  a  minute;  sometimes  slower. 
The  reason  is,  it  is  a  very  sensitive  test  of  the  voltage  that  is  passing 
through  the  wire.  It  has  been  often  noticed  that  when  the  lights  would 
go  up  high  it  would  make  the  room  light  enough.  ^'Mien  the  current 
is  at  a  high  voltage  the  lamp  is  heated  more,  and  that  works  the 


374  RESTORATICX  OF   TKF.Tll   HY  C  EM  EXT  ED  JXLAYS 

thermostat  quicker,  and  as  soon  as  it  is  worked  quicker,  it  immediately 
drops  down.    The  movement  is  caused  by  that  voltage. 

"The  wax  is  pLiced  on  the  glass  disk  and  the  even  temperature 
throughout  the  whole  mass  has  a  great  deal  more  to  do  with  the  correct 
moulding  of  wax  in  a  tooth  cavity  than  appears.  It  is  peculiar,  but  a 
soft,  wobbly  condition  of  the  surface  of  the  wax  wnll  invariably  make  it 
shrink  from  the  cavity  walls;  whereas,  if  the  wax  is  of  a  uniform  texture, 
it  will  move  to  its  place  in  an  exact  way,  and  there  will  be  no  change  in 
form  when  it  cools  off. 

"Investments  for  Cast  Inlays. — This  problem  of  investments  seems  to 
ha\e  caused  more  trouble  than  even  the  wax  problem  did,  and  justly  so, 
as  after  the  pattern,  which  must  be  accurate,  the  mould  must  be  scien- 
tifically correct.  A  great  many  of  the  faulty  adaptations,  aside  from 
those  caused  by  distorted  patterns,  come  from  improper  inxestments, 
or  good  investments  improperly  handled. 

"One  WTiter  has  gi\'en  several  pages  of  meaningless  statistics  about 
investments.  I  have  not  been  able  to  fathom  their  meaning,  because, 
if  investments  are  tested  under  conditions  w'hich  should  never  be 
allowed,  no  number  of  pages  of  statistics  can  make  me  believe  that  this 
would  be  a  scientific  treatment  of  the  subject.  For  instance,  temper- 
atures of  1000°  are  mentioned;  as  a  matter  of  fact,  such  a  temper- 
ature is  so  far  beyond  the  requirements  that  the  article  loses  w'eight 
as  a  scientific  treatise.  The  temperature  required  in  order  to  do 
scientific  casting  should  never  be  higher  than  just  enough  to  burn  out 
the  w^ax.  Anything  beyond  this  is  absolutely  harmful  and  brings  the 
investment  to  a  temperature  where  the  ingredients  themselves  are  burned 
and  give  off  gases  which  are  very  objectionable  in  a  mould. 

"The  temperature  in  the  flask  at  which  casting  should  be  done  has 
not  been  thoroughly  understood.  A  hot  flask  is  an  expanded  flask,  and 
an  expanded  flask  means  an  expanded  hole  inside,  and  an  expanded  hole 
means  a  misfit  casting. 

"  I  think  one  of  the  most  scientific  reasons  why  I  have  such  continu- 
ously satisfactory  accuracy  in  the  fits  of  my  cav' ities  lies  in  the  fact  that  I 
never  cast  in  a  mould  hotter  than  the  temperature  of  the  room.  In 
other  words,  always  allow  the  flask  to  become  cold.  This  gives  two  con- 
ditions, both  important.  One  is,  the  mould  is  not  distorted,  and  the 
other  is,  that  the  metal  flask,  in  being  allowed  to  come  back  to  a  normal 
temperature,  hugs  the  investment  tighter  and  gives  it  a  support  which 
is  very  helpful  in  resisting  the  pressure  from  within. 

"Most  of  the  handling  of  investments  is  done  in  a  very  unscientific 
way;  as  a  rule,  there  are  no  two  times  that  the  conditions  are  made  the 
same.  Experiments  in  sufficient  number  should  be  made  to  determine 
the  correct  quantities  of  water  and  powder,  and  then  these  proportions 
should  invariably  be  duplicated;  otherwise,  how  can  uniform  results  be 
obtained?    There  must  be  some  proportion  of  water  and  powder  in  any 


CEMEXTS  AXD  MAMl'l  LATION  375 

investment,  good  or  bad,  which  is  the  correct  one  for  best  results  with 
that  particuhir  investment,  and  when  this  is  determined  it  should 
invariably  be  duplicated.  This  can  only  be  done  by  weighing  the 
ingredients  and  not  by  measuring,  as  it  is  impossible  to  always  get  the 
same  quantity  of  powder  in  a  \'essel  unless  it  is  weighed.  A  little  pressure 
or  tapping  will  alter  the  quantity  away  beyond  reason.  From  the  start 
I  have  insisted  on  exact  weighing  of  both  water  and  powder,  and  this 
accounts  again  for  a  high  percentage  of  uniform  results  in  my  work.  A 
rule  of  thumb  method  will  never  accomplish  scientific  casting.  A  little 
water  and  a  little  powder,  and  if  too  thick,  a  little  more  water;  and  if 
this  time  it  is  too  thin,  then  a  little  more  powder,  will  never  gi\-e  two 
mixtures  alike,  and  if  the  consistency  of  mould  is  not  twice  alike,  the 
casting  results  certainly  cannot  be  duplicated. 

"  A  good  investment  should  be  so  compounded  as  to  make  it  possible 
to  pour  it  into  the  flask,  and  have  plenty  of  time  to  know  that  the  wax 
is  thoroughly  surrounded.  A  thin  investment  also  allows  the  contained 
air  to  more  easily  escape.  ^Yhen  I  was  using  a  thick  investment  and 
manipulating  it  hurriedly,  as  was  necessary,  I  would  find  pimples  on  the 
gold  far  in  excess  of  what  I  thought  was  caused  by  the  contained  air 
in  the  plaster  ingredient,  and  I  came  to  the  conclusion  that  gases  must 
be  evolved  after  the  investment  was  in  its  place  in  the  flask.  By  making 
a  proper  mixture  of  ingredients,  it  now  allows  me  so  to  manipulate  the 
material  that  any  contained  air  or  gases  are  allowed  to  escape  before 
the  flask  is  filled. 

"In  order  easily  to  weigh  and  mix  investments  to  get  uniform 
results,  I  have  devised  several  instruments  by  means  of  which  this 
object  can  be  obtained  and  scientific  casting  has  taken  a  long  step 
forward. 

"  Investment  B/Iixer. — This  apparatus  was  among  my  first  instruments 
for  mixing  investments.  It  is  an  open  tube,  and  a  movable  other  end 
to  the  lever.  In  the  centre  is  the  fulcrum.  There  is  a  movable  weight. 
Imagine  the  fulcrum  at  a  certain  point.  On  top  of  it  I  have  a  spirit  level. 
Without  that  it  would  be  impossible  to  tell  with  the  eye  whether  this 
end  or  that  end  was  too  low.  If  either  condition  existed  correct  pro- 
portions of  water  and  powder  could  not  be  obtained.  As  soon  as  the 
spirit  level  comes  to  a  centre,  that  is  the  correct  amount. 

"This  is  a  movable  weight  between  two  nuts.  ^Mien  it  is  to  the 
left  there  is  a  certain  amount  of  powder,  and  when  to  the  right  there  is  a 
certain  amount  of  liquid. 

"The  spirit  level  shows  the  weighing  beam  is  level.  I  now  move 
the  weight  over  to  the  right  side.  That  brings  it  out  of  balance.  By 
squirting  the  water  in,  and  bringing  it  back  to  balance,  we  have  the 
correct  quantity  of  water. 

"Those  two  ingredients  are  in  there  in  the  proper  proportions,  and 
those  conditions  can  be  duplicated  every  time,  and  after  the  proper 


370  RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

proportions  liave  lurri  found,  the  a(l\;inta{,'e  can  he  seen.  It  is  liquid 
enou^'h  to  shake  it  and  K<^'t  the  in^^redients  i)roperly  mixed. 

"The  element  of  time  comes  in.  These  gases  seem  to  be  evolved 
from  the  chemical  action  of  the  water  on  the  ])laster,  hence  the  liberation 
of  contained  air  and  gases.  The  plaster  taking  up  the  water,  whatevei 
gases  or  contained  air  there  may  be  in  the  powder  or  water,  are  given  a 
chance  to  be  eliminated  l)y  rolling  it  from  one  end  of  the  tube  to  the 
other,  and  giving  it  a  slight  tap  occasionally.  As  it  is  rolled  in  this  way 
the  gases  come  to  the  surface.  They  have  a  great  attraction  for  the 
water,  but  a  little  taj)  or  jar  will  break  them  loose,  and  then  the  process 
is  repeated  and  the  rotary  motion  given.  Three  or  four  minutes  of  time 
can  be  consumed  in  this  way,  and  the  investment  is  still  in  a  workable 
condition. 

"  When  it  is  ready,  the  inlay  which  is  on  the  crucible  former  is  care- 
fully painted  over  with  a  small  camel's-hair  brush,  so  that  there  is  no  air 
pocket  concealed  in  any  angle,  and  the  investment  is  then  poured  into 
the  flask.  It  is  in  a  liquid  condition,  and  is  absolutely  free  from  all  the 
gases  and  bubbles  that  have  formerly  caused  annoyance,  and  which 
invariably  produced  the  little  nodules  of  gold  on  the  surface  of  a  filling. 
It  is  easily  seen  how  a  thick  investment  could  confine  this  air,  and  the 
air,  ha\ing  some  buoyancy,  will  rise  somewhat;  but  it  has  not  enough 
buoyancy  to  come  out,  especially  when  it  strikes  the  under  side  of  the 
inlay.  Any  jarring  of  the  flask  at  this  time  is  the  worst  thing  that  can 
be  done,  because,  the  colonies  of  small  bubbles  of  air  and  gases  congre- 
gate and  cling  to  the  under  side  of  the  wax  pattern.  The  investment 
stays  thin  for  ten  or  ele\en  minutes,  and  apparently  it  is  so  liquid  it 
never  will  set;  but  when  it  is  looked  at  again  after  turning  aside  for 
a  moment  and  forgetting  it,  it  has  set.  It  turns  rapidly  from  a  liquid 
to  a  solid.  At  the  end  of  twenty  minutes  it  is  ready,  even  \\hen  mixed 
in  this  liquid  form,  to  place  on  the  fire. 

"In  order  to  mix  these  ingredients  properly  I  felt  as  though  the 
instrument  was  rather  crude,  and  that  a  more  accurate  and  automatic 
instrument  should  be  made  (Fig.  405). 

"In  this  vessel  I  mix  the  ingredients.  There  is  a  spring  that  allows  the 
rod  to  be  shortened.  It  was  j)ut  in  a  little  hole  in  one  side,  and  one  on 
the  other  side.  In  the  other  device  there  was  a  chance  to  change  the 
length  of  the  lever  in  the  scale  beam.  In  other  words,  in  dropping  the 
powder  into  it  the  bulk  of  it  would  ])ile  up  on  one  side.  That  would 
make  the  beam  longer,  and  a  true  measurement  would  not  be  obtained. 
If  it  were  possible  always  to  place  it  absolutely  in  the  centre  it  would 
weigh  properly.  The  liquid  takes  care  of  itself.  I  made  a  movable 
joint  in  this,  so  when  the  powder  is  put  in,  it  tips  it  over  and  brings  the 
centre  of  gravity  below  the  point  of  support. 

"The  instrument  is  handled  as  follows:  I  hang  it  on  the  fulcrum. 
The  arm  has  a  spirit  level  in  the  top,  the  same  as  the  other.    The  weight 


CEMENTS  AND  MANIPULATION 


377 


is  pushed  to  one  side,  tlie  powder  is  plaeed  earefuUy;  it  must  be  remem- 
bered that  a  little  too  mueli  j)()\v(ler  or  too  much  water  will  make  it  of 
such  a  consistency  that  it  will  not  roll  in  the  container,  l)ut  will  become 
sluggish  and  mushy.  The  wei«2:ht  is  now  moved  to  the  other  side  of  the 
scale  beam.  Water  is  poured  in  until  it  comes  to  a  balance  again.  The 
spring  is  removed  and  the  lid  placed  on  and  shaken  up  so  as  to  get  the 
ingredients  mixed.  It  will  be  noticed  that  the  arm  leading  oflF  from  it  is 
placed  at  an  angle.  This  is  placed  on  the  motor,  and  we  have  a  cog 
motion  here  which  reduces  the  speed  of  the  container  to  about  sixty 


Fig.  405 


revolutions  a  minute.  This  mechanism  is  an  automatic  one.  In  my 
w^ork  I  allow  five  minutes  for  the  mixing.  Five  minutes  is  better  than 
three  minutes,  because  every  chance  is  given  the  gases  to  escape  in  this 
time,  and  the  five  minutes  may  be  occupied  with  other  work.  I  take 
the  wax  inlay  after  it  has  been  placed  on  the  sprue  w^ire,  start  the 
automatic  instrument,  and  then  do  the  artistic  carving  and  finish  up 
the  wax  filling;  and  often  I  have  plenty  of  time  to  do  all  the  carving  that 
is  necessary  while  this  mixing  of  investment  is  going  on.  By  setting  the 
clock  at  five  minutes  the  mechanism  revolves.    There  is  a  little  jerking 


378 


HESTORATin.y  or  teeth  by  cemexted  is  lays 


motion  each  timr.  This  jar  is  to  burst  the  air  or  ^'as  bubbles.  The  bell 
riiiKs  and  the  machine  stops  automatically.  The  automatic  device  for 
stoi)ping  is  nothing  more  than  a  snap  switch  placed  on  the  alarm  end 
of  the  clock,  so  that  the  alarm  movement  is  the  one  that  throws  off 
the  switch. 

"The  material  is  now  ready  to  be  poured  into  the  flask.  It  is  of  a 
much  better  consistency  e\en  in  the  few  minutes  I  have  mixed  it — freer 
from  air  bubbles — than  in  any  other  wa\'  in  which  I  can  mix  it.  If  it  is 
jarred  in  a  more  violent  manner  more  air  is  apt  to  be  pumped  into  it. 

"By  allowing  the  disk  to  revohe  alone  the  angle  at  which  the  con- 
tainer is  set  is  continually  changing,  which  keeps  the  liquid  investment 
constantly  changing  its  place  and  spreads  it  in  a  thin  layer  on  the  inside, 
and  the  jar  l)virsts  the  gas  bubble. 

Fig.  406 


"There  is  another  automatic  mixer  (Fig.  406)  that  can  be  connected 
with  any  of  the  lathe  motors.  This  is  a  Ritter.  This  machine  works  on 
the  same  principle  as  the  other.  As  the  mixing  goes  on  for  the 
requisite  number  of  minutes  the  clock  movement  goes  along,  and  the 
jarring  motion  is  obtained.  The  fact  that  there  is  an  alarm  loud  enough 
to  draw  attention  to  the  fact  that  the  work  is  ready,  is  be^tter  than  the 
assistance  of  anyone  in  the  mixing.  It  permits  the  work  to  be  done 
identically  every  time. 

"Method  of  Removing  Wax  from  Mould. — The  case  is  now  flasked.  It 
is  seldom  that  wax  has  been  burned  out  successfully  twice  alike.  As 
this  process  takes  considerable  time  and  it  is  not  considered  necessary 
to  watch  it,  there  is  great  likelihood  of  overheating  and  spoiling  the 
mould  by  forgetting  it,  sometimes  leaving  it  on  the  flame  for  hours.  If 
continuously  duplicating  conditions,  as  I  have  previously  outlined,  is 


CEMENTS  AND  MANIPULATION 


379 


of  any  importance  in  scientific  castin^j,  it  is  equally  so  in  the  simple 
burning  of  the  wax.  I  ha\'e  devised  a  burner  for  this  purpose  which 
does  the  work  automaticallx-  and  thus  becomes  a  great  time  saver. 

"  Automatic  Apparatus  for  Burning  Out  the  Wax. — In  this  instrument 
(Fig.  407)  I  ha\'e  three  diti'erent  degrees  of  flame.  If  great  care  is  taken 
when  the  first  low  heat  is  put  on,  and  ])lenty  of  time  allowed  for  the 
water  to  be  e^■aporated  out  of  the  iuA-estment,  as  much  heat  as  is 
desired  may  afterward  be  put  on  and  as  fast  as  may  be  wished. 

Fig.  407 


"This  low  heat  is  without  signification  unless  it  is  confined.  The 
swaying  of  the  flame  by  draughts  would  mean  continual  variations  of 
temperature.  I  put  a  tube  over  as  a  chimney  to  make  the  flame  come 
to  the  top  always  and  to  prevent  its  swaising. 

'On  the  back  part  of  another  alarm  clock  there  is  a  disk  which  has 
three  steps  and  a  valve  of  special  construction.  This  level  first  rests  on 
the  first  step,  and  as  it  is  set  for  five  minutes  the  clock  moves  at  that  low 
heat,  and  then  drops  on  to  the  step  next  higher.  That  temperature  is 
kept  up  for  another  five  minutes,  which  precludes  the  possibility  of  any 
further  moisture  which  might  suddenh'  burst  and  destrov  the  invest- 


380  RESTORATIOX  OF   TEETH   HY  CEMENTED  INLAYS 

ment.  As  time  goes  on — another  fixe  minutes — it  drops  oft',  and  it  goes 
up  another  st(>[).  That,  we  will  say.  is  the  third  and  hi^diest  temi)erature. 
At  the  end  of  that  time  another  live  minutes  elapse,  and  the  switch  goes 
off  and  the  flame  goes  out. 

"Gold  for  Casting.  -The  next  pliase  of  seientific  casting  concerns  the 
gold  itself.  If  there  is  any  one  thing  more  than  another  which  has 
hindered  the  seientific  casting  of  inlays,  it  has  been  the  eagerness  of 
the  dentist  to  use  all  of  the  old  refuse  gold  about  the  office.  The  question 
of  sax'ing  on  an  average  sized  filling,  say  as  large  as  one  and  a  half  penny- 
weights, would  amount  to  ten  cents  when  pure  gold  scrap  is  used.  In 
the  case  of  22  k  scrap,  fourteen  cents  would  be  saved  on  the  filling,  and 
in  20  k  scrap,  about  sixteen  cents.  For  a  filling  of  this  size  not  less  than 
ten  dollars  should  be  obtained,  and  not  more  than  a  Innidred.  Now 
let  us  see  how^  this  figures  as  to  cost.  If  a  failure  occurs  on  account 
of  using  bad  gold  on  a  22  k  scrap  filling  at  ten  dollars  each,  it  would 
require  seventy-one  and  three-sevenths  fillings,  and  on  the  one  hundred 
dollar  filling,  seven  hundred  and  fourteen  and  two-sevenths  fillings 
to  come  out  even  on  that  one  failure.  Real,  ethical,  scientific,  artistic, 
humanitarian,  and  opposed-to-patents  dentists  cannot  afford  to  pros- 
titute themselves  to  this  extent. 

"So  much  for  the  commercial  side.  Now,  as  to  the  scientific  aspect 
of  knowledge  gained  and  verified  by  exact  observation  and  correct 
thinking. 

"Dental  golds  are  alloyed  with  either  silver  or  copper,  and  in  case 
of  solders,  zinc  is  used.  It  is  a  well-known  fact  that  silver  and  copper, 
or  any  baser  metals,  readily  absorb  gases  when  melted,  and  these  gases, 
prineij)ally  oxygen,  form  oxids  of  the  metal,  and  on  cooling  evolve  these 
gases,  which  causes  the  blowholes,  or  porous  cast.  The  elimination 
of  these  absorbed  gases  also  causes  the  sputtering  in  alloyed  gold, 
which  does  not  occur  when  pure  gold  is  used,  as  the  latter  in  its 
melted  state  does  not  absorb  gases;  consequently,  when  cooled  from 
the  melted  condition,  it  has  no  gases  to  squeeze  out,  and  it  is  necessarily 
exceedingly  homogeneous. 

"While  it  is  known  that  platinum  is  non-oxidizable,  and  might 
have  properties  helpful  to  gold,  it  must  be  borne  in  mind  that  platinum 
at  these  high  temperatures  has  a  very  great  affinity  for  silicon,  and  a 
piece  of  pure  platinum  melted  in  a  crucible  with  but  a  small  portion 
of  silica  will  become  very  brittle.  This  possibly  accounts  for  the  brittle- 
ness  of  clasp  gold  when  cast,  as  clasp  gold  is  supposed  to  be  alloyed  with 
platinum. 

"All  of  these  conditions  I  have  found  out  by  practical  experience,  and 
have  had  them  verified  l)y  expert  metallurgists.  What  do  these  experi- 
ments mean?  They  mean  that  if  cast  inlay  fillings  are  to  be  made 
in  a  truly  scientific  manner  pure  gold  must  be  used.  There  are  also  a 
great  number  more  of  clinical  reasons  favoring  the  use  of  pure  gold. 


CEMENTS  AND  MANIPULATION 


381 


"But  what  is  to  be  done  in  cases  where  more  strength  is  required,  as 
in  bridge  spans,  phitcs,  etc.?  Choose  the  lesser  of  the  two  evils  and 
use  coin  gold,  which  is  alloyed  with  copper,  and  if  not  melted  over 
and  over  again  the  gases  do  not  injure  its  ultimate  structure  as  they  do 
silver,  zinc,  and  platinum. 

"Casting  against  Pick-ups. — One  more  principle  about  gold  should 
be  mentioned,  the  casting  of  it  to  other  pieces  of  gold  which  are  in 
the  flask. 

"  Without  any  experience  except  that  gained  by  blowpipe  work,  the 
first  thought  which  seems  to  come  to  dentists  when  they  wish  to  cast 
against  gold  is  to  bring  both  the  golds  to  as  near  the  same  temperature 
as  possible.    This  process  absolutely  defeats  the  object  sought. 

"In  bringing  the  flask  and  its  contents  up  to  a  bright  red  heat,  the 
enclosed  metal  is  brought  to  a  temperature  at  which  it  oxidizes,  and 
as  there  are  no  means  of  deoxidizing  this  surface,  a  less  perfect  union  is 
obtained  when  the  melted  gold  is  thrown  in  than  when  the  case  is 
heated  up  to  a  temperature  just  sufficient  to  burn  out  the  wax.  This 
temperature  does  not  absolutely  burn  all  the  carbon  off  the  enclosed 
gold,  and  as  carbon  is  one  of  the  very  best  deoxidizers,  the  gold  is  now 
in  the  very  best  condition  to  be  welded  to  other  gold.  The  proper 
scientific  method  in  order  to  cast  to  this  gold  is  to  bring  the  melted  metal 
up  to  an  excessive  temperature. 

Fig.  408 


Jameson's  casting  machine. 


"Pressure. — The  pressure  used  is  an  important  factor  in  scientific 
casting.  It  may  be  too  low  to  do  accurate  casting,  or,  on  the  other  hand, 
too  high.  The  intermediate  pressure  which  is  just  right  can  only  be 
obtained  by  automatic  controlling  mechanism." 


382  RESTORATIOX  OF   TEETH   BY  CEMESTED  I. \ LAYS 

Tlic  introfluctioii  of  the  'Ja^r^rarf   iiiacliiiic  was  (|uickly  followed  hy 
maiiv  others.  soiii(>  of  them   iiotal)lv  iii(renious.      That  hv  Dr.  ("usteris 


l-io.   -lO'J 


Price's  casting  machine. 


Fui.   -110 


.~tHlg   IriartiHie. 


(listiiietly  (liferent  from  all  others  becau.se  of  the  fact  that  the  eold  is 
melted  In-  electricity.  This  machine  has  been  withdrawn  from  the 
market,  but  was  a  favorite  for  some  time. 


CEMENTS  AND  MANIPULATION  383 

Jameson's  is  a<i;ain  ditt'erent  because  the  njold  is  thrown  into  the  mould 
by  centrifugal  force  (Fig.  408).  This  machine  is  circular  in  form,  with 
extended  arms,  on  one  of  which  is  the  mould  and  crucible  for  melting 
gold.  These  are  set  in  motion  by  releasing  a  strong  spring,  forcing 
the  arms  to  revolve  at  a  rapid  rate,  which  throws  the  gold  into  the  mould. 
This  apparatus  is  very  efficient.  There  are  several  others  of  the  same 
principle  used  on  lathes  and  home-made  contrivances,  which  cast  by 
holding  in  the  hand  and  swinging  in  the  air.  Dr.  Weston  A.  Price  has 
devised  a  most  interesting  and  effective  electric  casting  machine,  entirely 
different  in  design  from  all  others  of  that  kind,  and  as  it  is  deserving  of 
more  than  passing  notice.  Dr.  Price's  description  is  given: 

"  The  centrifugal  casting  machine  shown  in  Figs.  409  and  410  was 
designed  both  for  experimental  and  practical  work,  and  is  particularly 
satisfactory  and  efficient  for  both. 

"  The  gold  is  melted  to  the  desired  temperature  in  a  crucible  in  a 
resistance  muffle  like  the  muffle  of  a  porcelain  furnace.  The  tempera- 
ture of  the  gold  is  indicated  by  the  pyrometer.  The  muffle  and  its 
contained  crucible  are  in  the  vertical  position  until  the  instrument  is 
started  revolving.  The  cup  carrying  the  investment  to  be  cast  into  is 
inverted  over  the  crucible. 

"  Since  the  rate  of  the  revolution  is  a  constant  factor  in  determining 
the  actual  pressure,  together  with  the  weight  of  the  column  of  fluid, 
and  the  radius  of  the  circle,  an  indicating  needle  is  geared  to  the 
driving  shaft,  and  indicates  the  pressure  being  exerted  by  the  fluid 
gold. 

"  When  ready  to  cast,  the  head  carrying  the  muffle,  crucible,  and 
investment  is  revolved  by  the  hand  lever,  and  the  heat  remains  on 
until  it  automatically  releases  itself  by  a  counterweight  condensing  a 
spring  and  opening  a  latch.  The  gold  thus  enters  the  investment  at 
high  pressure  and  at  the  full  heat.  Twenty  per  cent,  platinum  in  gold 
can  readily  be  melted  in  it. 

"  Large  cups  are  used  for  large  cases  like  plates  and  bridges. 

"  It  is  particularly  valuable  for  casting  into  hard  models,  like  the 
artificial  stone  which  can  withstand  a  very  high  pressure  without 
distortion." 

The  most  popular  machines,  because  of  their  cheapness  and  simplicity, 
are  those  of  the  press  or  stamping  form,  and  the  Seymour  is  representative 
of  that  class  (Fig.  411). 

The  metal  is  forced  into  the  mould  by  wet  asbestos  packing  pressed 
over  the  flask  rim.  This  contact  with  the  heat  produces  steam, 
which  forces  the  molten  metal  into  the  mould.  Bridges  and  full  den- 
tures are  successfully  cast  with  these  appliances. 

Successful  casting  does  not  always  depend  upon  the  machine  employed, 
as  due  consideration  must  be  given  to  the  technique  and  the  quality 
of  materials  used  such  as  wax  and  investment.     These  articles  are  as 


384 


RESTORATION  OF   TEETH   BY  CEMESTEI)  I  SLAYS 


varini  as  the  niacliiiics  and  their  merit  (h-jx-iids  lar^'ely  on  the  niain'pu- 
hitor,  ahhoiii^h  it  is  now  (generally  eoneeded  that  an  investment  composed 
of  three  ])arts  of  powdered  silex  to  one  (  f  hest  impression  plaster  will 
give  the  l)est  results  under  all  circumstances. 


I'l.^.  Ill 


Ijiqtl 


Seymour's  casting  machine. 


ALEXANDER'S  METHOD  OF  MAKING  GOLD  INLAYS 


'I'his  is  a  simple  and  raj)id  way  of  making  gold  inlays,  and  with  a  little 
experience,  accurate  results  can  be  obtained.  A  plastic  monldable  gold 
is  made  especially  for  this  purpose,  and  is  used  in  the  following  manner: 
Tear  from  the  plastic  gold  matt  a  piece  of  gold  of  sufficient  size  and  com- 
press into  a  double-headed  cone,  using  the  greatest  force  possible  with 
the  fingers,  then  introduce  it  to  the  cavity  prepared  as  in  Fig.  412. 
These  cavities  in  bicuspids  and  molars  are  prepared  with  a  retention  pit, 
differing  from  other  cavities  formed  for  inlay  work.  The  cavity  and  gold 
are  kept  dry  until  the  gold  is  packed  with  instrument  pressure,  using 
various  sizes  of  burnishers  for  this  purpose.  The  gold  being  very  plastic 
it  can  be  handled  similar  to  a  wax  impression,  noting  the  occlusion  and 
finishing  the  surface  in  the  same  manner. 

If  the  gold  pellet  is  deficient  in  size  it  can  be  added  to  providing  the 
surfaces  are  dry  when  the  form  is  complete;  it  is  then  removed  from  the 
cavity  and  invested.  'J'he  investment  is  made  to  form  a  slight  crater- 
shaped  gateway  through  which  the  gold  solder  enters  when  placed  and 
fused  upon  this  surface  (Fig.  413);    20  or  22  k  solder  should  be  used 


ALEXANDER'S  METHOD  OF  MAKING  GOLD  INLAYS        385 

for  solidifvint]^,  cut  into  small  s(juares  and  mixed  with  freshly  ground 
crystal  borax. 


Fia.  412 


Fig.  413 


A,  plastic  gold  for  making  inlaj's;  B, 
portion  of  plastic  gold  moulded  into  a  double 
cone;  C,  the  same  teased  into  approxi- 
mately the  shape  of  the  cavity;  D,  fused 
inlay,  shov^nng  excess  of  gold  in  button  at 
the  left;  E.  cavity  prepared  with  Sat 
seats,  a  and  6,  to  support  the  inlay. 


Soft  iron  loop,  as  made  and  as  embedded 
in  position  on  the  investment,  in  the 
crater  of  which  is  seen  the  plastic  gold 
ready  to  receive  the  solder. 


Fig.  414 


Soldering  apparatus:  Adjustable  gas-burner,  soldering  frame  and  support,  with  investment  in 
position,  with  the  flame  properly  applied.  The  ring  for  confining  the  flame  is  placed  on  the  wire 
frame  around  the  investment  and  another  wire  frame  on  top  of  the  ring. 

The  piece  is  slowly  heated  over  a  Bunsen  burner  (Fig.  414),  then  with 
a  broad  brush  flame  from  the  blowpipe,'  causing  the  solder  to  fuse  and 
be  absorbed  by  the  gold  within  the  investment.  Before  seating  the 
inlay,  it  should  be  finished  with  a  corundum  wheel,  being  careful  to 
trim  away  all  overlaps  along  margins. 
25 


3SG  RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

No  time  Avhiitcver  is  lost  in  niakinf];  inljus  by  tliis  inotliod,  as  tlie  heat 
is  ap})lied  while  the  investment  is  green.  The  paper  upon  which  it  is 
nuule  is  burnt  up  in  the  process  of  solidification.  Sump  is  used  for  the 
investment,  as  it  does  not  disintegrate  from  immediate  application  of 
heat. 

MAKING  INLAYS  BY  THE  SWAGING  PROCESS 

V\h\\v  the  inaiority  of  porcelain  workers  arc  satisfied  that  the  best 
results  are  to  be  obtained  by  working  directly  on  the  tooth  from  start 
to  finish,  it  is  claimed  by  others  that  results  ecjually  as  good  may  be 
had  by  swaging,  or  by  what  was  originally  known  as  the  water-bag 
process,  introduced  a  few  years  ago  by  a  London  manufacturing  firm. 

The  system  has  some  ardent  supporters  who  claim  that  by  it  the 
presence  of  the  patient  is  needed  only  for  the  impression  and  the  finish  of 
the  inlav,  the  rest  of  the  operation  being  done  in  the  patient's  absence 
and  by  a  laboratory  assistant  if  so  desired.  The  claim  is  plausible,  and 
from  the  fact  that  many  dentists  use  this  process,  makes  it  worthy  of 
consideration. 

Dr.  T.  T.  Van  Woert  is  an  ardent  supporter  of  this  form  of  operating, 
and  in  a  recent  article  on  this  subject  says:  "The  essentials  necessary 
for  securing  an  accurate  impression  of  any  cavity  are  ( 1)  suitable  trays; 
(2)  proper  impression  material,  and  (3)  a  knowledge  of  its  manipulation. 

"The  material  for  trays  which  have  given  me  the  most  satisfaction  is 
sheet  platinoid  of  32,  34,  and  36  gauge,  because  it  has  a  rigidity,  together 
with  more  plial^ility  than  any  other  metal  than  I  have  been  able  to  find. 
Another  ver}^  good  quality,  while  not  essential,  is  that  it  has  a  finely 
finished  surface,  which  at  least  has  the  appearance  of  being  clean,  and  is 
pleasing  to  the  patient.  The  second  requisite  is  the  impression  material, 
and  while  it  is  a  matter  of  opinion,  personally,  I  prefer  that  made  by 
the  Detroit  Dental  ^Ifg.  Co.,  because  it  softens  at  a  lower  temperature, 
sets  quicker,  and  when  cold  is  as  hard  if  not  harder,  and  gives  a  very 
much  sharper  definition  of  detail  than  others  I  have  tried.  After  forming 
the  tray,  a  suital)le  (juantity  of  compound  heated,  the  tray  held  over  the 
flame  until  it  is  hot  enough  for  the  material  to  adhere  to  it,  and  the 
compound  then  pressed  into  a  cone-shaped  mass  with  the  fingers  and 
then  chilled.  The  surface  of  the  cone  should  be  held  in  a  small  flame, 
so  that  it  is  (juickly  heated  to  the  point  of  running,  and  then  forced 
into  position,  and  either  compressed  air  or  cold  water  used  for  setting  it. 

"I  find  it  a  great  advantage  in  large  cavities  in  molars  and  bicuspids 
to  force  between  the  tray  and  adjoining  tooth  the  l)lade  of  a  thin  cement 
spatula  to  bring  up  a  sharp  line  at  the  cervix.  This  is  easily  removed 
after  the  chilling,  and  facilitates  the  removal  of  the  impression  as  well. 
This  is  frequently  advantageous  in  approximal  cavities  of  the  anterior 
teeth  also. 


MAKING  INLAYS  BY  THE  SWAGING  PROCESS  387 

"Method  of  Making  Amalgam  Models.  If  we  have  succeeded  in 
securino-  an  accurate  impression,  it  is  only  the  hetriiniiiio-  of  a  successful 
ultimate  result,  and  the  next  procedure,  that  of  making  the  model, 
re(|uires  as  careful  consideration  and  manipulation  as  any  part  of  the 
technique,  ^'arious  materials  have  been  recommeiided  for  this  purpose, 
all  of  which  I  have  given  a  most  careful  and  impartial  trial,  and  1  am 
forced  to  the  conclusion  that  there  is  hut  one  reliable  material,  and  that 
is  a  good  amalgam.  When  I  say  'a  good  amalgam,'  I  mean  one  having 
good  edge  strength,  as  little  shrinkage  as  possible,  and  the  property  of 
setting  quickly,  although  this  is  not  essential.  I  use  the  standard  alloy 
made  after  one  of  Dr.  Black's  formuUie. 

"First  the  impression  must  be  embedded  in  plaster  to  a  sufficient 
depth,  and  with  enough  body  surrounding  it  to  permit  of  pressing  the 
amalgam  well  down  into  the  impression.  The  amalgam  is  then  mixed 
with  enough  mercury  to  make  it  very  plastic,  and  this  is  burnished  into 
place  with  suitable  instruments  until  the  impression  is  filled.  Then  the 
excess  of  mercury  can  be  eliminated  by  folding  a  piece  of  rubber  dam 
several  times,  and  placing  it  on  the  amalgam  and  pressing  upon  it  with 
the  thumb. 

"The  mixing  of  the  amalgam  is  one  of  the  most  important  points  in 
the  procedure.  In  my  early  efforts  I  tried  to  fill  these  impressions  as  I 
would  a  cavity  in  a  tooth,  and  the  force  required  in  burnishing  it  to  place 
invariably  marred  the  impression  which  resulted  in  an  imperfect  model 
of  the  cavity. 

"Advantages  of  Impression  Method.— If  we  succeed  in  getting  an 
accurate  model,  a  filling  made  to  fit  it  must  fit  the  cavity  which  it  repre- 
sents. This  being  the  case,  let  us  consider  the  advantages  to  be  derived 
from  the  impression  method:  First,  we  are  none  of  us  so  perfect  in  any 
branch  of  our  art  that  we  are  not  liable  to  make  mistakes.  Second,  it  is 
beyond  question  that  we  all  have  many  accidents  that  are  just  as  deplor- 
able as  the  mistakes  we  might  make,  and  when  such  happens  in  the 
direct  method  of  making  inlays,  we  are  obliged  to  acquaint  our  patients 
with  the  fact  that  we  have  erred,  or  met  with  a  misfortune  in  the  form 
of  an  accident,  either  of  which  is  humiliating  to  the  operator  and  fre- 
quently exasperating  to  the  patient,  and,  occasionally,  to  such  an  extent 
that  the  patient  loses  confidence  and  seeks  service  elsewhere. 

"^Ye  will  take,  for  example,  porcelain  restorations.  In  the  direct 
method,  where  the  matrix  is  burnished  to  the  cavity,  which,  by  the  way, 
is  a  much  more  tedious  operation  than  that  of  taking  an  impression, 
we  have  confronting  us  the  possibility  of  some  distortion  in  its  removal, 
or,  perhaps,  in  the  handling  after  it  has  been  successfully  removed,  as 
well  as  the  possibility  of  warping  in  the  fusing  of  the  porcelain  itself. 
There  is  still  further  the  diflficulty  w^hich  arises  in  many  cases  of  securing 
a  suitable  color,  or  just  the  proper  form  of  contour,  all  of  which  is  a  large 
combination  of  defects  which  remains  to  be  explained  to  the  patient, 


388  RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 

"The  impression  method  eliminates  all  of  these  difficulties.  In  the 
first  place,  the  matrix  is  secured  by  s\ved<ring  the  gold  into  the  die  with  the 
Brewster  press,  and  tiie  swedged  matrix  is  less  likely  to  change  its  shape 
when  removed  than  the  burnished  one.  The  shape  of  the  swedged 
matrix  can  be  retained  by  filling  it  with  a  hard  wax;  it  is  then  removed 
and  invested,  and  later  the  wax  washed  out.  Should  the  filling  prove 
a  failure,  another,  or  several  others,  if  nece.ssary,  can  be  made  without 
the  patient's  knowledge;  and  where  the  (juestion  of  color  or  contour  is 
liable  to  cause  trouble,  several  fillings,  varying  from  a  light  to  a  dark 
shade,  can  be  made;  or  if  it  be  a  troublesome  contour,  several  of  different 
shapes,  so  that  when  the  patient  presents,  the  suitable  filling  can  be 
selected  without  subjecting  him  to  another  or  several  operations,  and 
without  the  unnecessary  loss  of  time  to  the  operator. 

"Cast-gold  Fillings. — The  same  procedure  is  applicable  with  cast- 
gold  inlays,  with  the  exception  that  the  wax  filling  is  fitted  to  the  tooth,  as 
described  by  Dr.  Taggart,  omitting  the  final  carving  of  detail  in  l)ite  and 
contour  which  should  be  done  to  the  die.  If  the  die  is  correct,  the  wax 
filling  will  go  to  place  without  difficulty;  but  one  is  surprised  to  note  the 
little  defects  in  the  filling,  such  as  here  and  there  a  small  point  where 
the  wax  has  not  conformed  to  the  sharp  edge  of  the  cavity  margin.  This 
is  due  to  the  lack  of  resistance  at  such  places;  the  wax  being  of  one  tem- 
perature throughout  its  entire  body,  it  is  forced  by  the  occlusion  from 
inward  out,  and  on  a  Hne  with  the  cavity  margin.  It  may  be  said  that 
this  defect  can  be  remedied  by  running  a  hot  spatula  around  the  line, 
but  I  have  found  this  extremely  difficult,  particularly  at  the  cervix.  It  is 
also  claimed  that  such  defects  may  be  corrected  by  burnishing  the  gold 
casting  after  it  has  been  cemented  to  place.  This  has  proved  just  as 
difficult  and  unreliable  in  my  hands;  and  it  is  a  potent  point  that  these 
difficulties  do  not  exist  when  cast  fillings  are  made  from  the  impression 
and  amalgam  model  properly  constructed." 


THE  BREWSTER  PRESS  AND  MATERIALS 

The  cavity  is  prepared  as  tlescribed  for  the  usual  method,  edges  s{|uare, 
margins  strong,  and  without  undercut.  Talcum  powder  is  rubbed  into 
the  cavity  and  adjacent  surfaces. 

Then  an  impression  is  taken  in  cement.  This  is  invested  in  plaster 
of  Paris,  and  the  surplus  cement  which  extended  around  the  tooth  on 
both  sides  of  the  cavity  is  trimmed  away  to  about  one-sixteenth  of  an 
inch  from  the  margins.  Additional  cement  is  then  mixed  to  a  very  stiff 
consistency,  the  fingers  being  dipped  in  talcum  powder  and  the  cement 
well  kneaded.  The  first  impression  is  surfaced  with  talcum,  and  this 
second  mix  pressed  into  the  first  one  and  allowed  to  stand  until  c|uite 
hard.    Then  separate  and  invest  this  second  impression  or  model  in  one 


THE  BREWSTER  PRESS  AND  MATERIALS 


389 


of  the  stet'l  cu|).s,  in  plaster,  or,  if  preferred,  in  one  of  the  very  shallow 
c'iij)s,  in  cement  or  sealing  wax.  Invest  so  that  the  centre  is  sli<rhtly 
hii>her  than  the  edges  of  tlie  cnp.  When  the  plaster  is  liard,  place  a 
scjuare  piece  of  platinnni  (one  one-thousandth  of  an  inch  thick)  on  the 
cement  model.  With  pledgets  of  cotton  wool  press  the  platinum  down 
into  the  cavity;  put  into  the  swager,  with  a  water  bag  over  the  wool,  and 


Fic;.   41r 


Fig.  410 


Fig.  417 


Fig.   418 


swage.  Remove  from  the  swager  and  burnish  out  wrinkles  or  folds; 
then  anneal  well  in  the  furnace,  replace  on  the  model  and  re-swage  with 
water  bag,  but  without  the  wool.  Reverse  the  press  handles,  remove  the 
cup  from  the  cylinder,  and  examine  the  matrix.  If  any  WTinkles  or  folds 
still  remain  on  the  margins,  they  must  be  burnished  out;  and  if  the  matrix 
does  not  appear  to  be  perfectly  adapted  to  all  parts  of  the  cavit}\  it  should 


390 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 


he  au;;iiii  annealed  and  tlicMi  suhjeeted  to  harder  pressure  in  the  swaf^er. 
Any  eraek  in  the  matrix  at  the  hottoni  or  near  the  bottom  of  the  cavity 
will  not  atVeet  the  fit  of  an  inlay. 

In  huildin^  in  the  porcelain  where  the  cavity  is  a  large  one,  first  grind 
an  "  inlay  rod"  to  fit  tightly  across  the  matrix  at  its  widest  part;  surround 
this,  excej)t  upon  its  upper  surface,  with  foundation  body;  and  when  it 
is  cpiite  (irv,  bake.  Keep  the  foundation  body  sufficiently  away  from 
margins  to  allow  for  the  thickness  of  enamel  body  necessary  to  produce 
the  desired  color.  When  baked,  return  to  the  model,  and  if  in  baking 
the  foundation  body  has  caused  any  change  in  the  fit  of  the  matrix,  the 
next  swaging  will  correct  it.  After  this  last  swaging  proceed  to  fill  in  the 
enamel  body.    Lay  the  dark  shades  in  first  and  bake;  then  add  the  lighter 


Fi<;.  419 


1 


rr- 

'"T'l 

•> 

^h 

GH  CEMEMT 

::r 

IMPRESSION 

falsi: 

colors  necessarv  to  finish.  The  foundation  body  first  baked  in  the 
matrix  will  {)revent  any  change  of  form  during  the  baking  of  the  enamel 
body. 

The  press  should  be  screwed  to  the  bench.  The  solid  rubber  is  for 
swaging  heavy  metal  cusps  and  also  for  inlays.  Should  a  water  bag 
break,  carefully  dry  out  the  cylinder  and  plunger.  Do  not  allow  any 
rust  to  accumulate  in  the  cylinder.  The  inlay  rods  above  mentioned  are 
made  of  high  fusing  material  and  are  of  assistance  in  large  contour  work 
by  other  methods. 

The  most  recent  appliance  for  this  process  is  the  Roach  model  press 
with  trays  which  are  cut  to  form  of  cavity  and  are  recommended  for 
bicuspids  and  molars. 


CHAPTER    XIV 

THE  TREATr^IEXT  AND  FILLING  OF  ROOT  CANALS. 
By  otto  E.  IXGLIS,  D.D.S. 

The  treatment  of  root  canals  necessarily  depends  upon  the  patho- 
logical condition  encountered.  This  may  consist  simply  in  the  necessity 
for  removal  of  a  perfectly  healthy  pulp  for  mechanical  or  prophylactic 
reasons,  or  it  may  involve  the  treatment  of  profound  disease,  such  as 
apical  or  even  more  complicated  abscess.  Each  case  therefore  must  be 
considered  by  itself,  yet  for  the  purpose  of  this  chapter,  root  canal  cases 
may  be  divided  into  three  classes:  (1)  Those  in  which  the  pulp  is 
entirely  or  in  part  vital;  (2)  those  in  which  the  pulp  is  dead;  (3)  mixed 
cases.    Cases  of  each  class  may  be  either  septic  or  non-septic. 

CASES  IN  WHICH  THE  PULP  IS  VITAL 

These  cases  will  be  considered  under  the  follo^ving  separate  sub- 
headings : 

A.  Cases  of  Healthy  Pulps  Covered  by  a  Sufficient  Layer  of  Dentin. 
Not  infrequently  the  removal  of  a  healthy  pulp  is  demanded  for  the  pur- 
pose of  permitting  better  anchorage  of  fillings  or  inlays  by  means  of  pins, 
screws,  etc.  The  use  of  dowelled  crowns,  the  fixation  of  a  bridge  at  one 
or  more  piers  by  means  of  devices  involving  the  use  of  pins  anchored  in 
root  canals,  or  the  growing  practice  of  previously  devitahzing  and  treating 
the  canals  of  such  teeth  as  are  to  receive  hollow  metal  crowns  as  bridge 
anchorages,  demands  pulp  removal.  Such  pulp  removal  followed  by 
proper  canal  treatment  is  not  only  warrantable,  but  ad^•isable  in  many 
cases  as  against  other  methods  of  procedure,  each  case  to  be  considered 
upon  its  merits. 

B.  Cases  of  Pulps  Covered  by  Sufficient  Dentin,  but  Exhibiting  Evi- 
dences of  Irritability. — In  some  cases  the  recession  of  the  gum  may  cause 
an  irreducible  h^'persensitivity  of  the  dentin  which  may  have  been 
produced  by  the  action  of  scalers  or  by  the  contact  of  food  masses  with 
the  necks  of  teeth,  or  caries  may  have  resulted  of  such  extensive  char- 
acter as  to  keep  the  pulp  in  such  a  state  of  irritability  as  to  permit 
constant  reactions  to  cold  or  sometimes  hot  substances  taken  into  the 
mouth. 

(391) 


392  TREATMENT  AS  I)  l-ILLISd  OF  ROOT  CAXALH 

Not  infrequently  the  pain  associated  with  the  excavation  of  such 
cavities,  together  with  the  possibility  that  thermal  shocks  will  continue 
after  filling,  indicate  the  removal  of  .'■uch  pulps.  Deeper  cavities  of  decay 
sometimes  jM-rmit  the  impress  of  temperature  changes  or  the  irritation 
of  sweet,  salt,  or  acid  substances  which  cause  profound  arterial  hyjx-r- 
emia  of  the  pulp,  with  its  loss  of  tone  in  the  bloodvessels,  followed  by 
their  expansion  by  the  pressure  of  the  blood  in  them.  In  such  cases 
venous  hyperemia  of  the  pulp  may  ensue. 

The  condition  of  determination  of  blood  to  a  pulp  or  arterial  hyper- 
emia also  occurs  in  consequence  of  the  presence  of  large  metallic  fillings 
near  a  pulp;  deep  erosions  or  abrasions;  metallic  crowns  on  teeth  con- 
taining vital  j)ulps;  leaking  fillings  producing  a  septic  irritation  of  the 
fibrils,  but  a  non-septic  irritation  of  the  pulp  body;  fractures  exposing 
the  dentin;  pyorrhea  upon  sound  or  filled  teeth;  also  infected  socket  or 
aphthous  ulcer;  near  proximity  of  an  abscess  upon  another  tooth;  blows 
and  reflex  irritations  from  other  teeth. 

Some  of  these  conditions  require  remo\al  of  the  pulp.  The  reflex 
cases  due  to  contiguous  inflamed  areas,  the  excess  of  blo(xl  in  them 
overflowing  into  an  otherwise  healthy  pulp,  require,  as  a  rule,  attention 
to  the  causal  ctmdition  rather  than  to  the  symj)toms. 

When  venous  hyperemia  follows  arterial  hyperemia,  it  is  due  to  com- 
pression of  the  vein  at  the  apex,  preventing  a  return  of  blood  to  the 
heart.  The  vessels  expand  greatly,  diapedesis  of  red  corpuscles  may 
occur,  and  the  pulp  usually  dies,  so  the  prognosis  is  bad. 

The  necessity  for  devitalization  depends  upon  the  mechanical  pro- 
cedures to  be  carried  out  and  also  upon  the  response  to  sedative  and 
protective  therapeutics,  if  a  preliminary  trial  of  the  same  has  been 
considered  advisable. 

Arterial  hyperemia  which  has  followed  the  introduction  of  a  metal 
filling,  and  esi)ecially  of  a  large  gold  filling  or  inlay,  and  whicli  becomes 
increasingly  profound,  so  that  slight  thermal  changes  cause  the  patient 
great  discomfort,  indicates,  as  a  rule,  the  devitalization  of  the  pulp,  it 
being  assumed  that  sedative  therapeutics  are  inapplicable  or  liable  to 
be  inefi'ective.    The  same  is  true  of  vital  teeth  carrying  metal  crowns. 

Secondary  dentin  and  pulp  nodules  are  in  themselves  associated  with 
degeneration  of  the  dental  pulp,  but  may  lead  to  further  degeneration, 
so  that  reflex  disturbances  may  be  produced.  Reactions  to  thermal 
shock  may  or  may  not  be  in  evidence,  though  they  usually  are. 

If  discomfort  be  produced  by  this  the  pulp  should  be  removed. 

Idiopathic  hyperemia  sometimes  appears  in  a  single  tooth.  The 
cause  being  difficult,  if  not  impossible,  of  determination  without  pulp 
extirpation,  this  should  be  done. 

C.  Cases  of  Pulps  Recently  Exposed. — The  removal  of  a  last  layer  of 
decalcified  dentin,  or  sometimes  of  disintegrated  dentin,  or  careless 
exca\ating,  may  cause  the  exposure  of  a  pulp.     Unless  capping  be 


CASES  IN    WHICH   rilM  J'CLI'   IS    VITAL  393 

for  some  reason  iiidicuted,  the  extirpation  of  tlio  |)uip  is  indicated. 
When  decalcified  dentin  in  some  mass  has  been  removed  from  over 
the  apparently  healthy  pnip  horn,  the  pnip  itself  may  for  prao 
tical  purposes  be  rej^ardcd  as  aseptic  and  possibly  hyperemic,  while  if 
exposed  by  decay  or  covered  by  boj^^'y,  infected  dentin  it  may  be 
regarded  as  superficially  infected  and  inflamed.  In  no  case  can 
the  character  of  the  infection  l)e  determined  without  microscopic 
examination,  unless  pus  be  actually  present,  when,  of  course,  pyogenic 
organisms  must  be  in  the  pulp.  In  either  case  an  antiseptic  sedative, 
such  as  phenol  camphor  or  eugenol,  should  be  placed  against  it  for  a 
short  time.  Whether  the  extirpation  shall  be  under  cocain  anesthesia 
or  after  the  use  of  arsenic  depends  upon  the  circumstances.  As  a  rule, 
pressure  anesthesia  with  cocain  is  a  safe  method. 

In  the  forgoing  classes  of  cases  cocain  pressure  anesthesia  is  usually 
the  most  prompt  method  of  preparing  the  pulp  for  removal. 

While  an  exposed  pulp  should,  as  a  rule,  be  removed,  two  conditions 
may  be  excepted:  First,  when  the  exposure  has  occurred  during  excava- 
tion of  leathery  decalcified  dentin  in  fully  formed  teeth  and  the  pulp 
seems  uninfected  and  without  marked  hyperemic  reaction.  Even  here 
it  is  better  to  confine  conservation  to  anterior  teeth  in  patients  of  good 
physical  condition  for  the  sake  of  maintaining  the  translucency  of  the 
teeth.  The  second  condition  exists  when  a  root  is,  in  all  probability, 
not  fully  developed  or  very  much  resorbed,  and  the  pulp  should  be 
conserved  in  order  to  permit  it  to  perform  its  share  in  the  develop- 
ment or  resorption  of  the  root.  Even  though  it  be  exposed  by  caries 
and  be  infected  or  irritated,  the  chance  of  saving  it  for  this  purpose 
should  be  taken.  The  open  character  of  the  root  end  and  the  size  of 
the  pulp  favors  the  distribution  of  any  hyperemia  which  may  exist  or 
arise.  In  any  case  the  pulp  is  expected  to  cover  itself  with  secondary 
dentin  or  to  lie  quiescent  against  the  capping  material,  and  either  result 
may  accrue,  as  subsequent  uncovering  of  pulps  comfortably  capped  for 
several  years  has  shown. 

These  advantages  have  several  offsetting  disadvantageous  possibilities 
which  render  capping  ordinarily  inadvisable  except  for  the  object  stated 
above.    These  are: 

1.  Possible  death  of  the  pulp  through  hyperemia  due  to  thermal 
changes. 

2.  An  overproduction  of  secondary  dentin,  the  production  of  pulp 
nodules,  or  other  degenerative  changes,  the  pulp  becoming  exhausted 
and  death  ensuing.  Increased  difficulty  of  subsequent  canal  treatment 
may  result. 

3.  Disease  of  the  pulp  due  to  infection  beneath  the  capping  material. 

4.  The  time  required  for  assurance  of  success  or  failure. 

From  the  foregoing  it  will  be  seen  that  a  pulp  capping  should  be  a 
non-conductor  of  thermal  changes  and  antiseptic  or  even  germicidal  in 


394  TREATMENT  AND  FILLING  OF  ROOT  CANALS 

character;  it  should  also  be  rigid,  sedative,  and  a})i)licahle  witliout  press- 
ure, of  which  a  l)ulp  is  intolerant,  as  it  is  a  mechanical  cause  of  pulp 
irritation.  These  needs  are  all  met  by  the  use  of  a  sedative  antiseptic 
cement.  A  mixture  of  zinc  oxid  and  thymol  made  while  the  latter  is 
melted  makes  a  cappinj?  fulfilling  these  conditions.  A  small  piece  of 
the  solid  mixture  is  melted  and  a  portion  carried  on  a  burnisher  or 
within  a  metal  cap  to  the  pulp.  A  crystal  of  thymol  placed  on  this 
will  hasten  the  setting  of  the  mass.  Another  good  example  is  Jodo- 
Formagen,  which  contains  phenol,  eugenol,  and  formaldehyd,  together 
with  iodin  salts.  While  the  exact  formula  is  not  published,  its  value 
is  amply  proved.  It  may  be  applied  either  with  or  without  a  metal 
cap.  It  is  preferable,  as  a  rule,  to  use  a  bit  of  paper  to  carry  the  paste 
to  place,  later  removing  the  paper,  or  to  flow  it  gently  o\ev  an  exposure 
and  adjacent  dentin  by  means  of  a  ball  burnisher.  It  soon  sets,  and 
when  rigid  fulfils  the  object  of  a  metal  cap,  namely,  a  protector  against 
the  pressure  of  material  subsequently  introduced.  As  a  rule,  it  is  better 
to  cover  it  with  zinc  phosfate  to  which  about  5  per  cent,  of  powdered 
thymol  has  been  added. 

The  manner  of  using  the  cement  depends  upon  the  amount  of  reten- 
tion and  the  character  of  the  metal  filling.  When  amalgam  is  to  be 
used  there  is  often  ad\'antage  in  making  a  combination  filling  in  which 
soft  cement  is  placed  in  the  cavity  and  amalgam  pushed  into  it  in  such 
a  way  as  to  distribute  the  cement  about  the  cavity  and  retentions  as 
a  thin  lining  adhering  both  to  the  walls  and  to  the  amalgam.  Under 
conditions  which  allow  of  a  large  mass  of  cement,  this  may  be  made 
quite  stiff  and  be  gently  packed  into  the  cavity,  approximately  shaped, 
and,  when  set,  finally  shaped  to  form  a  supporting  intermediate  or 
base  for  the  filling. 

Other  capping  cements  of  less  value  are  oxysulfate  of  zinc,  plaster 
of  Paris,  and  oxychlorid  of  zinc.  The  first  consists  of  a  mixture  of 
uncalcined  zinc  oxid  and  a  saturated  solution  of  zinc  sulfate  in 
distilled  water.  The  plaster  of  Paris  should  be  mixed  with  a  1  per  cent, 
aqueous  solution  of  formaldehyd.  The  oxychlorid  consists  of  calcined 
zinc  oxid  for  the  powder  and  a  solution  of  zinc  chlorid  for  the  liquid. 
The  liquid  should  be  modified  by  the  addition  of  distilled  water  in  the 
proportion  of  two  parts  of  the  liquid  to  one  of  water.  A  trifle  of  iodoform 
or  hydronaphthol  may  be  added  to  any  of  these  cements. 

When  a  lesser  condition  than  exposure  exists,  or,  in  other  words, 
a  condition  of  almost  exposure,  the  condition  of  the  pulp  should  be 
considered,  and  if  there  has  not  been  too  much  irritation,  the  pulpal 
wall  may  be  covered  with  Jodo-F'ormagen  or  thymol  and  zinc  and  the 
balance  of  the  cavity  be  filled  with  a  temporary  cement  filling.  The 
subsequent  comfort  or  irritability  of  the  pulp  will  decide  as  to  whether 
to  fill  the  tooth  or  devitalize  the  pulp.  In  all  other  cavity  conditions 
there  can  be  no  question  as  to  the  advisability  of  pulp  conservation 


CASES  IN  WHICH  THE  PULP  IS   VITAL 


39o 


Fig.  420 


provided  tlicre  be  no  symptoms  of  unusual  pathological  disturbance  lA' 
the  puij). 

There  may  be  sli^lit  or  pronounced  hyperemia  of  the  puij)  following'  a 
capping  operation  which  may  be  treated  by  means  of  counterirritants 
applied  to  tlie  jjum  e\ery  other  day.  If  successful,  the  irrital>ility  of 
the  pulp  will  gradually  subside  and  the  tooth  will  bear  hotter  and  colder 
applications  until  a  comparatively  normal  tolerance  is  reached.  Jack 
has  formulated  tlie  plan  of  testing  the  sound  lower  incisors  while  under 
a  rubber  dam  with  hot  and  cold  water  of  known  temperatures  until  pain 
is  produced,  this  being  regarded  as  the  normal  limit  of  thermal  toler- 
ance. He  has  shown  that  individual  reactions  differ,  pain  being  pro- 
duced at  from  74°  to  32°  F.  on  the  cold  side,  and  at  from  118°  to  152°  F. 
on  the  heat  side.  The  data  gained  by  this  test  may  justly  be  termed 
the  thermal  index  of  the  patient,  and  is  a  guide  in  judging  the  cure  of 
the  hyperemia.  Of  course,  if  a  failure  results,  the  hyperemia  will  become 
severe,  and  there  will  be  increasing  response  to  thermal  shock. 

D.  Cases  of  Vital  but  Septic  Pulps.— Mtal  pulps  may  be  infected  from 
one  of  three  possible  directions.  First  and  most  frequently  by  way  of 
the  orifice  of  the  pulp  horn  or  orifice  of 
exposure  in  case  of  a  cervical  cavity.  The 
infecting  organisms  may  traverse  either 
decalcified  or  disintegrated  dentin  overlying 
the  pulp,  but  quite  a  considerable  num- 
ber of  cases  have  been  observed  to  have 
followed  the  dentinal  tubules  beneath  a 
filling  or  to  have  penetrated  spaces  exist- 
ing in  secondary  dentin.  The  layer  of 
dentin  penetrated  may  be  nearly  one-quarter 
of  an  inch  in  thickness.  Without  question 
the  organisms  ha^'e  caused  decomposition  of 
the  fibrils  in  their  passage  to  the  pulp.  In 
such  cases  as  this  partial  suppuration  of 
the  pulp  may  ensue  (more  rarely  partial 
gangrene),  and  the  pus  is  confined  by  the 
dentinal  wall.  The  pathology  is  that  of 
abscess  when  the  dentin  so  confines  the  pus 

(Fig.  420) .  The  removal  of  boggy  dentin  from  over  a  pulp  horn  may  allow 
a  droplet  of  pus  to  escape,  and  in  more  rare  cases  a  copious  flow  of  pus 
occurs.  Sometimes  the  abscess  is  confined  within  the  body  of  the  pulp, 
which  has  a  white  or  yello-R-ish-white  appearance,  the  pus  only  escaping 
after  puncture  (Fig.  422).  When  the  pus  is  confined,  either  by  dentin  or 
the  body  of  the  pulp  itself,  the  symptoms  are  the  same,  namely,  a  delayed 
but  intense  reaction  to  heat,  due  to  expansion  of  the  gases  against  the 
pulp,  with  relief  from  cold  applications  due  to  the  contraction  of  the 
gases.    The  reaction  to  cold  is  sometimes  present  in  the  milder  forms. 


Abscess  of  the  pulp  after  forma- 
tion of  a  large  amount  of  secondary 
dentin,  dividing  the  pulp  into  two 
portions;  SD,  secondary  dentin; 
^'P,  vital  pulp;  AP,  abscess  or 
confined  pus;  I,  area  of  apical 
inflammation.  (Diagrammatic.) 

(After  a  case  in  the  mouth.) 


39() 


TREATMENT  AM)  FILLING  OF  ROOT  CANALS 


especiallx-  wlicii  ii  (Iccj)  cavity  is  i)roseiit.  The  peculiar  sporadic  cessation 
and  reappearance  of  tlie  i)aiii  when  the  pulp  is  not  subjected  to  thernml 
chaiijies  is  also  characteristic.  The  pathology  of  abscess  (a  circum- 
scribed cavity  eontainiuf,'  pus)  is  applicable  to  such  cases  as  these,  and 
a  diagnosis  of  such  condition  from  the  above  symptoms  is  warrantable. 
When  the  infection  has  destroyed  a  portion  of  the  pulp  by  suppuration, 
or  other  putrefactive  process,  but  the  egress  of  the  i)us,  etc.,  is  effected, 
owing  to  an  open  pulp  cavity,  the  pyogenic  erosion  of  the  pulp  may 
proceed  until  even  only  a  minute  portion  of  pulp  may  remain  vital  but 
evidently  infected.    This  is  known  as  ulceration  of  the  pulp,  becau.se  it 


Fig.  421 


^.diagram  of  lower  molar  with  caries  at  a  which  exposes  the  pulp;  the  darkened  portion  at  6  shows 
the  extent  of  the  inflammation;  the  rest  of  the  organ  was  free  from  inflammatory  change;  B,  illustra- 
tion of  the  inflamed  tissue,  showing  a  part  destroyed  by  suppuration  at  a;  the  odontoblasts  are  under- 
mined at  6.  the  bloodvessels  which  were  filled  with  blood  clot  in  the  section  are  left  blank  here,  that 
they  may  be  more  apparent.      (Black.) 


consists  of  an  inflamed  and  open  breach  in  the  continuity  of  the  pulp. 
The  symptoms  are  not,  as  a  rule,  severe,  consisting  of  gnawing  local  pain 
or  possibly  of  reflex  pain  in  other  parts  (Fig.  421). 

When  food  is  packed  into  the  cavity  the  pus  and  gases  become  con- 
fined and  the  symptoms  of  abscess  of  the  pulp  may  appear. 

The  writer  has  often  found  such  pulp  remnants  under  faulty  canal 
fillings,  in  one  case  after  the  roots  of  a  molar  had  been  partially  filled 
for  twelve  years.  In  some  cases  partial  gangrene  of  the  pulp  has  been 
found,  due  sometimes  to  neglected  cases  of  arsenical  application,  at 
others  to  the  production  of  venous  hyperemia  with  death  of  the  pulp 


CASES  IN   WHICH  THE  PULP  IS   VITAL 


397 


bulb  only,  kud  in  still  others  the  pulp  in  one  or  more  roots  of  a  molar 
has  remained  vital  while  the  pulp  in  another  root  has  undergone  com- 
plete moist  gangrene. 

Fiu.  422 


Acute  suppurative  pulpitis  in  the  coronal  portion:  7.  intensely  inflamed  horn;  A.  abscess;  V. 
bloodvessels  engorged  with  blood;  S,  superficially  inflamed  horn;  A'^,  nest  of  inflammation.  X  10. 
(Bodecker.) 


The  second  avenue  of  infection  of  a  pulp  is  by  way  of  the  apical 
tissue.  An  apical  abscess  on  a  root  of  an  adjoining  tooth  may  by  exten- 
sion of  its  pus  cause  apical  infection  of  the  pulp  of  another  tooth.  This 
will  cause  prompt  death  of  the  pulp  of  a  single-rooted  tooth,  but  may 
only  cause  inflammation  of  the  pulp  of  a  multirooted  tooth. 


398 


TREATMENT  AXIJ  I'lLLlMi  OF  HOOT  CASALS 


The  most  fn'(|U('iit  (•.•iiis(>  of  apical  infection  of  \i\\\\^  is,  however, 
found  in  cases  of  deep  jjvorrhea  ])ockets.  The  infection  liaxing  reached 
the  apex  causes  sucli  an  infection,  whicli  travels  downward  into  the 
pulp  of  the  denuded  root.  This  pulj)  filament  may  be  dead  or  partly 
vital,  while  the  filaments  in  other  roots  remain  vital  and  inflamed. 

The  third  direction,  or  infection  by  way  of  the  blood  stream,  is  a 
possibility,  but  the  condition  is  only  inferential  when  the  case  is  one 
associated  with  some  <j:(Mieral  or  profounrl  local  infection. 

E.  Hyperplasia  of  the  Pulp.-  The  exposure  of  the  pulp  leads  some- 
times to  a  chronic  constructive  inflammation  of  its  tissue.  The  pulp 
extrudes  into  the  cavit\'  of  decay,  often  fillinfj;  it.  Such  a  })ulp  may  be 
sui)puratinfi:  upon  its  surface,  and  at  times  it  seems  to  have  removed 
the  decay  from  about  it  as  though  the  walls  had  been  subjected  to  a 
resorptive  action. 

The  clinical  ai>i)earance  varies  considerably  (Figs.  423  to  428). 


Fig.  423 


Fk;.  424 


Fig.  425 


Fig.  426 


n.\  IxTtrnphy  of  pulps.      (Garret.''on.) 


Fiu.  427 


Fig.  428 


Hypertrophy  of  the  gum.      (Garrefson.) 


Hypertrophy  of  the  pericementum.      (Garretson.) 


The  hyperplastic  i)()rtion  of  the  ])ulp  may  be  frozen  with  ethyl  chlorid 
or  saturated  with  trichloracetic  acid  and  ablated.  The  balance  of  the 
pulp  usually  succumbs  to  ar.senic.  The  covering  is  best  made  in  cases 
with  little  cavity  retention  by  driving  a  fair-sized  wheel  bur  into  the 
side  of  the  concave  cavity.  A  thin,  fiat  piece  of  si)unk  is  then  laid 
upon  the  pulp  and  an  amalgam  covering  built  into  the  cuts  made  by 
the  bur.  Next,  the  amalgam  is  cut  through  and  the  spunk  gently  un- 
covered and  removed,  leaving  a  central  opening  in  which  arsenic  may 
readily  be  sealed.  The  location  of  the  polypoifl  growth  and  the  condi- 
tion of  the  tooth  surrounding  it,  will  generally  distinguish  it  from  a 
pol\'poid  gum.  If  uncertain,  it  should  be  pressed  away  with  cotton 
before  applying  arsenic. 


METHODS  OF  PULP  REMOVAL  399 


METHODS  OF  PULP  REMOVAL 


There  are  four  general  methods  by  which  a  patient  or  pulp  may  be 
prepared  for  the  operation  of  extirpation.    These  are  as  follows: 

1.  Anesthetization  of  the  patient  and  removal  of  the  pulp  during 
the  period  of  anesthesia. 

2.  Anesthetization  of  the  pulp  by  cocain,  or  in  some  cases  by  nervo- 
cidin  and  the  ^emo^•al  of  the  pulp. 

3.  Anesthetization  of  the  apical  tissue  and  removal  of  the  pulp. 

4.  Devitalization  of  the  pulp  followed  by  its  removal. 

1.  General  Anesthesia. — The  pulp  of  a  single-rooted  tooth  may  be 
readily  extirpated  while  the  patient  is  anesthetized  by  nitrous  oxid, 
nitrous  oxid  and  oxygen,  or  by  somnoform.  The  instruments  should 
be  in  readiness,  the  patient  anesthetized,  the  pulp  uncovered  by  an 
engine  bur,  and  the  pulp  extirpated  with  a  barbed  broach  or  Donaldson 
cleanser. 

In  cases  of  multirooted  teeth  the  available  anesthetics  are  ether, 
which  is  rarely  used  for  the  purpose,  and  nitrous  oxid  administered 
by  nasal  inhalation.  The  latter  is  accomplished  by  means  of  a  special 
apparatus  having  a  hood  covering  the  nose,  of  wliich  the  Teter  appli- 
ance is  the  most  notable  example.  This  is  designed  to  prolong  the 
anesthesia  by  administering  nitrous  oxid  and  oxygen.  As  it  is  equally 
applicable  to  the  otherwise  painful  excavation  of  cavities  of  decay  and 
extractions,  it  is  a  valuable  means  for  accomplishing  this  purpose  also. 

The  ordinary  outfit  is,  however,  of  value  by  enabling  the  operator  to 
remove  the  diseased  bulb  of  the  pulp  of  a  multirooted  tooth,  after 
which  and  while  the  patient  is  conscious  other  methods  of  remo\al 
of  the  radicular  portions  of  the  pulp  may  be  employed. 

2.  Anesthesia  of  the  Pulp. — For  this  purpose  cocain  is  almost  univer- 
sally employed.  There  are  three  practical  methods  by  which  it  may  be 
introduced  into  a  pulp: 

(a)  By  pressure  accomplished  by  means  of  raw  vulcanite.  A  strong 
solution  (50  per  cent,  to  saturated  solution)  of  cocain  hydrochlorid 
is  made  in  water,  or  preferably  in  some  mild  antiseptic  solution 
which  does  not  cloud  on  admixture.  A  small  piece  of  amadou  (spunk) 
is  saturated  with  it  and  laid  upon  the  orifice  of  exposure.  The  cavity 
is  filled  with  the  rubber,  and  upon  this  is  placed  a  flat-ended  plugger  or 
burnisher  broad  enough  to  concentrate  the  force  upon  the  amadou. 
A  broad  piece  of  amadou  placed  over  the  rubber  is  sometimes  of  assist- 
ance in  preventing  the  slipping  about  of  the  rubber.  Gentle  pressure 
is  now  made  and  a  slight  pain  is  usually  felt.  The  pressure  should  be 
maintained  until  this  passes  away,  then  it  is  increased  little  by  little 
until  some  force  is  exerted.  The  rubber  and  amadou  are  then  removed, 
the  pulp  cavity  opened,  the  progress  of  the  anesthesia  tested  with  a 


400  TREATMENT  AND  FILLING  OF  ROOT  CANALS 

fine  broach,  tind  the  pulp  lifted  away.  Some  prefer  to  j)hice  a  prepared 
pellet  or  ervstal  of  eoeain  upon  the  pulp. 

For  multirooted  teeth  the  pressure  should  he  prolonged,  and  to 
prevent  return  of  sensation  and  hemorrhage  while  extirpating  it  is  well 
to  instil  carbolic  acid  into  the  pulp  tissue  i)y  means  of  a  fine,  smooth 
broach. 

In  some  cases  the  operation  fails  because  the  direction  of  the  pressure 
has  been  away  from  rather  than  toward  the  pulp  or  because  the  spunk 
lias  slipped  from  its  place.  Sometimes  the  orifice  of  exposure  may  be 
enlarged,  but  as  sensation  is  discovered  a  fresh  application  must  be 
made. 

Sometimes  repeated  applications  fail  of  effect,  though  the  application 
is  not  painful,  and  at  times  the  pressure  is  not  tolerated  at  all,  owing  to 
the  irritability  of  the  pulp.  In  cases  of  cavities  without  walls  to  con- 
fine the  rubber,  it  is  well  to  enclose  the  buccal  and  lingual  embrasures 
with  the  thumb  and  forefinger.  In  very  broad  occlusal  cavities  the  finger 
tip  confines  the  rubber  nicely. 

When  only  canal  filaments  are  present,  any  septic  matter  should 
be  removed  by  .syringing  repeatedly  with  an  antiseptic  solution;  then 
the  canals  should  be  thoroughly  dried,  and  the  cocain,  dissolved  in  an 
antiseptic,  is  carried  on  a  cotton  thread  into  the  canals  and  against 
the  pulp  remnant.  A  small  piece  of  rubber  is  placed  in  one  canal  and 
the  pressure  confined  to  that  canal  by  means  of  a  plugger  which  will 
al)out  fill  the  canal .  The  action  is  dien  repeated  in  the  other  canals.  This 
produces  better  results  than  a  general  pressure  over  all  the  canals  at 
once. 

If  used  after  arsenic  has  been  applied  the  results  are  not  usually  so 
good,  but  sometimes  the  method  is  successful.  To  avoid  the  introduc- 
tion of  arsenic  into  apical  tissue  all  sloughing  portions  should  be  removed. 

AMien  the  pulp  is  not  exposed,  the  application  to  the  dentin  over  the 
pulp  permits  advance,  a  pocket  being  created  in  the  dentin  with  a  bur, 
which  aids  the  further  instillation  of  the  cocain;  finally,  the  pulp  is 
exposed  and  the  anesthesia  is  completed. 

Clyde  Davis  recommends  for  the  purpose  of  producing  the  exposure 
the  use  of  a  drop  of  1  to  1000  adrenalin  chlorid  followed  by  a  drop  of 
37  per  cent,  formaldehyd,  then  pressure  with  raw  vulcanite. 

There  is  a  possibility  of  the  introduction  of  cocain  into  the  general 
circulation,  and  some  .systemic  effect  may  be  noted,  though  often  this  will 
be  due  to  the  agitation  of  the  patient.  Some  patients  have  complained 
of  tingling  in  the  fingers.  If  .syncope  be  threatened  aromatic  spirit  of 
ammonia  should  l)e  administered,  the  head  lowered,  the  feet  elevated, 
and  smelling  salts  or  amyl  nitrite  applied  to  the  nostrils. 

Hemorrhage  following  the  extirpation  of  the  pulp  is  sometimes 
copious.  To  avoid  this,  carbolic  acid  .should  be  instilled  into  the  pulp 
tissue  bv  means  of  a  smooth  broach.     A  fine  Donaldson  cleanser  may 


METHODS  OF  I'ULl'  REMOVAL  401 

be  passed  to  the  apex  of  the  canal  and  slowly  twisted,  the  operation 
consuniint?  several  minutes.  This  torsion  of  the  pulp  largely  limits  the 
hemorrhage.  If  it  occurs  it  should  be  allowed  to  check  itself,  although 
if  desired  a  trifle  of  a  mixture  of  powdered  alum  and  powdered  thymol 
may  be  taken  upon  cotton  wet  with  phenol-camphor  and  passed  to  the 
end  of  the  canal.  Deliquesced  zinc  chloride  checks  hemorrhag  promptly, 
but  its  application  may  be  painful. 

It  is  an  open  question  whether  canals  from  which  li\ing  pulps  have 
been  remo^•ed  should  be  filled  immediately  or  not.  There  is  liable  to 
be  a  secondary  hemorrhage,  particularly  when  adrenalin  is  used  with  the 
cocain.  Many  prefer  to  fill  at  once,  claiming  that  surgical  pericementitis 
is  the  only  result.  The  WTiter,  as  a  rule,  WTaps  a  twist  of  cotton  upon 
a  Swiss  broach,  dips  it  into  phenol-camphor,  then  into  formocresol, 
and  applies  it  to  the  canal.  This,  as  a  rule,  permits  the  healing  of  the 
parts  without  much  tenderness,  and  really  consumes  but  little  more  time 
in  the  aggregate.  ]\Ioreover,  the  formocresol  tends  to  mummify  the 
fibrils  left  in  the  dentinal  tubules. 

As  an  alternate  upon  the  immediate  filling  side  a  paste  of 

I^— Thymol 1  part 

Paraform 1  part 

Zinc  oxid 1  part 

Glycerin 1  part 

may  be  used  with  gutta-percha  cones  to  accomplish  the  same  result. 
All  work  should  be  done  under  aseptic  precautions.  Where  applicable 
and  not  liable  to  be  too  painful,  the  rubber  dam  should  be  applied. 
The  WT-iter  often  uses  napkins  instead,  and  relies  upon  the  carbolic  acid 
instilled  into  the  pulp  and  the  formocresol  dressing  to  maintain 
asepsis.    Tliis  is  repeated  if  the  cavity  be  douched  out. 

FiQ.  429 


The  Myers  compound  syringe  for  forcing  cocain  solutions  through  the  dentinal  tubules. 

(6)  When  considera})le  dentin  overlies  the  pulp,  or  v,-hen  a  tooth  is 
sound,  the  most  expeditious  methotl  of  cocain  anesthesia  is  by  means  of 
the  compound  syringe  (Fig.  429) .  This  consists  of  a  strong  metal  syringe, 
the  piston  of  which  is  actuated  by  means  of  levers  which  multiply  the 
power  of  the  hand.  The  IVIyers  syringe  is  one  of  the  best,  although  several 
forms  are  obtainable.    The  syringe  nozzle  is  embedded  in  a  small  hole 

2a 


402  TREATMENT  AND  FILLING  OF  ROOT  CANALS 

(IrilUvl  in  tiie  dfiitin  by  one  of  two  mctliods.  The  liole  may  he  made 
small  with  i)arallel  sides,  as  when  drilled  with  a  No.  i  bur.  The  syrin^'e 
nozzle  has  then  slij^htly  conieal  sides  at  the  point  intended  to  jam  a  fit 
when  introdueed  with  foree  into  the  drill  ])it.  In  the  other  method  the 
drill  ])it  is  made  with  a  cone-pointed  bur  or  bud  bur,  and  the  syringe 
point  is  made  fiat-ended,  a  form  easy  to  maintain  upon  the  point.  A  4  to 
10  per  cent,  cocain  solution  is  suffieient,  and  all  air  must  be  expelled 
from  the  syringe.  It  is  wise  also  to  expel  all  air  from  the  drill  pit  by 
a  slight  pressure  while  the  syringe  point  is  loosely  held  in  the  pit.  Then 
a  rotary  motion  under  forward  i)ressure  eml)eds  the  point. 

If  no  leakage  oeeurs  the  force  of  the  piston  drives  the  cocain  through 
the  fibrils  in  the  tubules  and  into  the  pulp.  The  pressure  must  be  main- 
tained for  about  three  minutes.  The  anesthesia  is  then  tested  by  drilling 
with  a  No.  h  bur  in  the  direction  of  the  pulp.  If  the  dentin  be  sensitive 
the  SN'ringe  is  to  be  reapplied.  Often  the  bur  sinks  into  a  sensitive  pulp 
without  warning  by  dentinal  sensitivity.  In  such  case  the  syringe  is 
reapplied  for  a  moment,  when,  as  a  rule,  the  anesthesia  will  be  complete. 
In  all  cases  when  testing,  the  drill  hole  should  not  be  enlarged,  as  this 
prevents  reapplication.  Too  much  cocain  should  not  be  introduced, 
as  it  has  happened  that  the  area  about  the  apical  tissue  has  been  pro- 
foundly injected,  with,  of  course,  possibility  of  systemic  complication. 
This  warning  applies  to  the  second  application  rather  than  the  first. 
When  desirable,  the  enamel  of  a  sound  tooth  which  is  to  be  crowned  may 
be  ground  away  until  the  dentin  is  reached,  or  if  enamel  must  be  removed 
in  only  limited  degree,  as  for  a  tap  upon  the  lingual  side  of  an  incisor  or 
in  the  fissure  of  a  bicusi)id,  a  "  spot"  is  first  made  with  a  dentate  bur, 
then  a  spear  drill  is  driven  through  the  enamel  only  just  reaching  the 
dentin.  The  drill  hole  is  then  enlarged  as  widely  as  permissible,  after 
which  the  pit  is  made  in  the  dentin  with  a  No.  2  bur. 

The  lingual  side  of  upper  incisors  will  permit  of  sufficiently  direct 
pressure  to  enable  the  operator  to  centre  the  syringe  point,  but  in  many 
cases  in  which  crowns  are  indicated  the  labial  side  may  be  used  with 
advantage,  especially  at  the  neck  when  the  cementum  is  exposed.  Later, 
the  entrance  tap  is  made  in  line  with  the  pulp  axis.  The  la})ial  or  mesio- 
buccal  side  must  always  be  used  in  the  lower  teeth,  unless  a  cavitj''  be 
used,  sometimes  preferably  at  the  neck,  sometimes  higher  up.  In 
cavities  having  sufficient  dentin  over  the  pulp  the  pit  may  be  made  in 
the  pulpal  wall,  and  if  for  any  reason  it  is  needed  the  drill  pit  may  begin 
at  the  cervical  portion  of  the  cavity  and  extend  into  the  root  dentin 
and  parallel  with  the  pulp.  The  pit  must  be  deeper  than  the  syringe 
point  will  penetrate,  so  that  the  pressure  may  force  the  solution  laterally 
through  the  tubules,  which  are  at  a  right  angle  to  the  axis  of  the  pulp 
and  the  pit. 

The  considerations  pertaining  to  the  pulp  removal  are  the  same  as  in 
the  other  forms  of  pulp  anesthesia. 


METllUDS  UF  I' I  I  A'  REMOVAL  403 

(c)  Tlio  third  and  least  desirable  form  of  cocaiii  anesthesia  of  the  pulp 
consists  of  its  introduction  by  the  cataphoric  current.  It  has  the  dis- 
ad\antage  of  consuming]:  more  time,  but  may  serve  when  patients  are 
timid.  A  10  per  cent,  solution  of  cocain  hydrochlorid  is  applied  to  the 
pulpal  wall  of  the  cavity,  the  tooth  being  previously  placed  under  rubber 
dam.  The  anode  of  the  cataphoric  outfit  is  applied  to  the  cotton  and 
the  cathode  placed  in  the  hand  or  at  the  cheek. 

The  dentin  may  be  anesthetized  as  well.  If  desired,  this  method 
may  be  used  to  obtain  a  pulp  exposure  and  the  pressure  method  employed 
to  complete  the  operation. 

When  beginning  with  an  exposed  pulp,  about  fifteen  minutes  will  be 
required  unless  hyperemia  of  the  pulp  exists,  when  a  longer  time  will 
be  required.  As  with  the  pressure  method,  there  may  be  occasional 
failures.  It  will  be  noted  that  there  is  advantage  in  time  and  con- 
venience in  the  pressure  methods. 

(f/)  The  fourth  method  of  producing  pressure  anesthesia  consists  in 
the  use  of  carbolic  acid  in  place  of  the  cocain  or  in  case  of  obstinate 
canal  filaments  of  a  solution  of  cocain  in  carbolic  acid. 

When  pulp  nodules  or  calcific  degeneration  exists  there  may  be  some 
difficulty  in  introducing  the  cocain,  but  after  a  first  or  second  appli- 
cation the  nodule  may  be  hf ted  away  and  further  pressure  made,  although 
even  at  this  point  failure  may  occur. 

In  all  cases  presenting  difficulty  in  introduction,  desiccation  is  a 
valuable  prehminary.  Cook^  recommends  an  application  of  10  per  cent, 
sulfuric  acid  for  a  few  minutes,  followed  by  sodium  bicarbonate  pre- 
vious to  a  reapplication  of  the  pressure  anesthesia  as  highly  effective  in 
aiding  penetration  of  the  cocain. 

(e)  The  fifth  method  of  producing  pulpal  anesthesia  is  by  the  appli- 
cation of  nervocidin,  an  alkaloid  obtained  by  D.  Dalma  from  the 
East  Indian  plant  gasii-hasu.  Arkovy  recommended  that  a  portion 
be  applied  to  the  exposed  pulp  for  twenty-four  hours,  when  it  may  be 
removed  painlessly.  Soderberg  suggests  the  addition  of  a  small  amount 
of  cocain  hydrochlorid  to  overcome  the  primary  irritating  effect  of  the 
nervocidin.    He  prefers  the  following  combination: 

I^ — Gum  arable 5j 

Zinc  sulfate oss 

Water fSj— M. 

Dissolve  the  zinc  sulfate  in  the  water,  add  the  gum  arable,  stir,  let  stand  for 
twenty-four  hours,  and  strain. 

I^ — Of  above  solution f  oij 

Nervocidin gr.  X 

Cocain  hydrochlorid gr.  x — M. 

To  a  portion  of  the  latter  solution  add  uncalcined  zinc  oxld  to  make  a  cement 
which  is  placed  in  the  floor  of  the  dried  cavity.  Cover  with  cement.  If  dentin  be 
over  thp  pulp,  an  additional  application  of  twenty-four  hours'  duration  is  required  to 
obtain  an  exposure. 

1  Dental  Review,  1905. 


404  TREATMENT  AND  FILLING  OF  ROOT  CANALS 

3.  Paralyzation  of  the  Transmitting  Apparatus. — Tlie  third  general 
principle  upon  whicli  i)ulps  may  he  extiri)ate(l  consists  in  paralyzing 
the  nerve  filament  leading  from  the  pulp  to  the  larger  branches  of  the 
fifth  nerve.  If  the  nerve  in  the  aj)ical  tissue  can  be  prevented  from  trans- 
mitting sensation,  the  operator  may  remove  the  pulp  surgically  without 
pain.  The  apical  tissue  is  to  be  located  as  nearly  as  possible,  the  gum 
sterilized,  and  an  injection  of  about  five  drops  of  a  1  per  cent,  solution 
of  cocain  containing  adrenalin  injected  as  near  the  periosteum  of  the 
bone  as  possible.  This  is  expected  to  infiltrate  the  apical  tissue  via  the 
collateral  vessels  in  the  bone.  To  permit  the  accomplishment  of  this  a 
little  time  should  be  allowed.  On  drilling  the  dentin  to  open  the  pulp 
cavity,  one  should  note  the  presence  or  absence  of  sensation,  and  upon 
exposure  a  smooth  l)r()ach  should  be  used  to  test  the  state  of  the  pulp. 
In  the  use  of  this  method  precaution  should  be  taken  to  administer  an 
antidote  before  using  the  cocain.  What  is  called  diploe  anesthesia  has 
been  employed  to  relieve  the  pain  of  dental  operations,  and  consists  of 
cutting  to  the  bone  after  the  above  injection,  perforating  the  bone,  and 
injecting  into  the  diploeic  structure.  A  method  employed  by  some 
bridge-workers  consists  in  notching  and  excising  sound  crowns.  It  is 
claimed  that  for  a  short  period  after  the  excision  the  pulp  is  insensitive 
and  can  be  lifted  away  with  a  broach.  If  for  any  reason  this  should 
fail,  other  immediate  methods  can  be  employed 

4.  Devitalization  of  the  Pulp. — Devitalization  of  the  pulp  by  the  use 
of  arsenic  as  a  preliminary  to  its  successful  removal  is  the  oldest  of  the 
methods  employed  at  the  present  day,  and,  as  shown,  it  still  has  to  be 
resorted  to  either  from  necessity  or  convenience. 

The  method  has  its  value  in  the  very  teeth  in  which  its  use  is  least 
objectionable,  namely,  the  posterior  teeth.  There  is  no  danger  in  the 
use  of  arsenic  in  teeth  ha\'ing  completed  roots  or  in  unresorbed  tem- 
porary teeth,  provided  the  arsenic  be  accurately  sealed  in  the  cavity  so 
that  it  does  not  escape  upon  the  gum.  If  it  does  escape  it  may  destroy 
the  gum  or  pericementum  and  cause  partial  necrosis  of  bone  or  the  com- 
plete loss  of  the  tooth  together  with  some  bone.  The  pulp  always  dies 
through  a  process  of  venous  hyperemia  induced  by  the  protoplasmic 
irritant  and  poison.  This  hyperemia  is  progressive  from  the  pulp 
bulb  toward  the  apex  of  the  root,  and  there  it  causes  the  death  of  the 
a})ical  portion  of  pulp  through  interference  with  its  nutrition.  Some- 
times this  hyperemia  of  the  pulp  extends  into  the  apical  tissue,  but  if 
the  pulp  be  left  in  situ,  necrosis  of  apical  tissue  never  results,  but,  on 
the  contrary,  the  hy])eremia  becomes  resohed  after  the  death  of  the 
pulp. 

The  writer  fails  to  see  wherein  such  a  hyperemia  differs  in  consequence 
from  that  produced  by  the  surgical  removal  of  a  I)ulp  and  denominated 
with  favor  as  surgical  pericementitis.  In  his  hands  such  teeth  have 
given  quite  as  good  results  as  when  other  methods  have  been  employed. 


METHODS  OF  PULP  REMOVAL  405 

By  this  it  is  not  meant  that  there  has  been  no  difficulty  in  devitalizinji; 
some  pulps,  particularly  some  of  those  in  which  repeated  applications  of 
cocain  under  {)ressure  failed  to  anesthetize,  l)ut  that  when  carefully 
handled  and  sufficient  time  for  pulp  death  has  been  allowed,  careful 
filling  of  the  canal  has  been  successful. 

The  rational  objections  to  arsenic,  aside  from  its  escape  upon  the 
gum,  are:  (1)  The  possible  production  of  pain.  (2)  J\)ssihle  sulfusion  of 
the  tooth.    (3)  The  time  required. 

The  production  of  pain  may  largely  be  obviated  by  observance  of 
certain  technique.  The  pulp  should  ordinarily  be  exposed  and  be 
slightly  bled  to  relieve  any  hyperemia  or  inflammatory  engorgement 
present,  as  this  seems  to  prevent  the  absorption  of  the  arsenic.  A  power- 
ful sedative  such  as  thymol,  menthol,  cocain  hydrochlorid,  or  morphin 
acetate  should  be  employed  as  a  corrective,  and  the  menstruum  shouhl 
be  sedative  rather  than  coagulant.  All  pressure  on  the  pulp  should  be 
avoided,  as  this  produces  pain. 

Sufficient  time  for  complete  death  should  be  allowed,  say,  from  a 
week  to  ten  days.  If  upon  examination  with  a  fine  smooth  broach 
vitality  be  discovered,  a  sedative  should  be  applied  and  pulp  death 
awaited.  Leaving  the  dead  portion  against  the  vital  part  of  the  pulp 
is  even  better  than  making  a  second  application,  as  its  removal  relieves 
the  congestion  by  opening  the  vessels,  and  the  congestion  is  necessary  to 
the  end  in  view.  If  the  pulp  gives  but  little  response  upon  probing,  it 
may  be  removed.  Sometimes  the  diapedesis  of  red  corpuscles,  asso- 
ciated with  the  venous  hyperemia,  causes  a  staining  of  the  pulp  and 
dentinal  fibrils  with  the  liberated  hemoglobin.  This  is  unfortunate, 
but  can  be  treated  by  bleaching  with  25  per  cent,  ethereal  pyrozone 
sealed  in  the  pulp  cavity  for  about  twenty-four  hours  after  the  pulp 
is  removed.  The  third  objection,  the  matter  of  time,  does  not  apply 
to  the  cases  of  prompt  devitalization,  as  the  time  spent  in  pulpal 
anesthesia  and  checking  hemorrhage  is  in  the  aggregate  no  less  than  in 
the  arsenical  cases.  In  the  delayed  action  of  arsenic  the  objection  is 
valid,  but  the  apical  injection  and  general  anesthesia  methods  are  still 
open  to  trial.  The  arsenical  method,  of  course,  requires  a  longer  period 
of  treatment.  Pulpal  anesthesia  can  be  tried  when  arsenic  does  not 
act  well,  but  should  be  avoided  when  it  originally  failed.  As  stated, 
these  considerations  apply  mainly  to  posterior  teeth. 

The  following  is  an  excellent  formula  for  arsenical  paste: 

I^ — Arsenici  trioxidi gr.  xv 

Cocaini  hydrochloridi      . gr.  xx 

Thymolis  (vel  menthoiis) gr.  v 

Olei  caryophylli q.  s.  ft.  pasta— M. 

This  should  be  finely  ground  in  a  mortar  and  spread  over  the  bottom  of  a  wide 
glass  jar  so  that  some  of  the  paste  may  be  taken  up  from  the  bottom.  The  arsenic 
settles  to  the  bottom. 


406  TREATMENT  AXD  FILLING  OF  ROOT  CANALS 

Buckley  recommends  the  followiiii;  formula: 

1^ — Arsmic  (rioxid Kr.  ISO 

Cocain  alkaloid Kr.  30 

Thyniol pr.  15 

Petronal lU  15— M. 


Fig.  430 


There  are  some  advantages  in  the  so-called  devitahzing  fiber  intro- 
duced by  J.  Foster  Flagg.  To  make  this,  absori)ent  cotton  is  cross-cut 
with  scissors  to  a  fine  lint.  This  is  dusted  into  the  paste  or  ground  up 
with  it  in  the  mortar.  It  may  then  be  dried  on  a  blotter  and  be  bottled 
for  use.  As  it  lacks  long  fibers,  a  small  portion  may  be  detached  and  be 
placed  upon  the  pulp.  There  are  cases,  however,  in  which  the  paste 
should  be  carried  to  the  exposure  upon  a  probe  and  gently  inducted  into 
a  fine  exposure.  Here  its  tendency  to  spread  or  penetrate  is  valuable. 
The  fiber  has  no  such  tendency,  which  makes  it  less  dangerous  in  use. 
In  making  the  application  a  minute  portion  of  paste  is  to  be  laid  upon  the 
pulp,  or  a  pinhead  pellet  of  cotton  is  rolled  in  it,  the  excess  of  menstruum 
removed,  and  it  is  then  applied  to  the  pulp,  or  a  portion  of  devitalizing 
fiber  is  used.    This  is  then  sealed  in. 

The  cavity  should  be  prepared  for  the  reception  of  arsenic,  decay  being 
removed  as  far  as  practicable. 

There  are  two  good  methods  of  sealing  the  arsenic.  In  cases  not 
approaching  the  gum,  or  where  dryness  can  be  maintained,  the  applica- 
tion may  be  accurately  made  and  quick- 
setting  cement  flowed  over  it.  This  cement 
is  capable  of  being  fairly  dropped  into  a 
cavity  or  led  around  the  periphery  by  a 
probe,  and  should  be  very  adhesive,  also  be 
readily  removable.  A  still  safer  method 
consists  in  applying  a  pellet  of  amadou  over 
a  part  of  the  pulpal  wall.  The  cement  is 
then  introduced  about  the  periphery  of  the 
cavity,  the  amadou  being  left  largely  uncov- 
ered. When  hard,  any  cement  over  the 
amadou  is  removed  and  the  latter  lifted 
out,  thus  leaving  a  box-like  receptacle  for 
the  arsenic  and  a  pellet  of  amadou  partly 
Avet  with  eugenol  in  which  menthol  is  dis- 
solved. When  placed,  the  orifice  is  dried  and  more  cement  added. 
This  method  of  first  making  the  covering  is  of  special  advantage 
when  the  cavity  cervix  is  near  the  gum  and  prevents  the  forcing  of 
arsenic  toward  the  gum  in  the  act  of  making  the  covering.  Amalgam 
or  facing  amalgam  may  be  used  in  place  of  the  cement  (Fig.  430). 

The  rubber  dam  is  generally  insisted  upon,  but  cannot  be  used  in 
the  worst  cases,  hence  an  expert  may  dispense   with  it.     There  is  a 


Diagram  showiDg  method  of  first 
making  the  covering  for  an  arsenical 
or  sedative  application.  (See  text.) 
EP,  exposed  pulp;  AA,  arsenical 
application;  C,  sedative  covering  to 
same;  A,  amalgam  placed  before 
thes  applications;  A',  amalgam  to 
seal  them  in,  E,  enamel. 


METHODS  OF  PULI'  REMOVAL 


407 


tendency  among  students  to  rely  upon  the  rubber  dam  alone  to  prevent 
accidents.  This  is  a  fallacy,  as  the  same  results  may  occur  with  it  as 
well  as  without  it.  The  chief  danger  lies  in  the  use  of  temporary  stopping 
after  placing  paste.  Capillarity  and  pressure  often  carry  the  paste 
to  the  cervical  margin.  Making  the  covering  first  or  using  fiber  con- 
stitute the  best  precautions. 

In  case  of  a  very  dangerous  cavity,  as  a  distocervical  one,  a  special 
drill  pit  known  as  a  "  pocket"  is  to  be  made  at  some  other  point  extending 
in  the  direction  of  the  pulp  horn  and  as  near  to  it  as  can  be  made  with- 
out too  much  infliction  of  pain.  In  this  the  arsenic  is  to  be  sealed  while 
antiseptic  sedatives  are  to  be  placed  on  cotton  in  the  cavity  of  decay. 

The  presence  of  pulp  nodules  may  necessitate  an  application  after 
lifting  away  the  nodule  (Fig.  431). 


Calcification  of  the  dental  pulp:  At  A  is  shown  the  outline  of  a  lower  molar  with  a  cavity  at  h. 
The  pulp  chamber  is  much  reduced  in  size  and  filled  with  calcific  material,  as  shown  in  B.  a,  a,  large 
granular  mass  of  calcific  material,  which  is  very  transparent  but  finely  granular.  A  very  few  irregular 
lines  are  seen  in  the  centre,  which  slightly  resemble  dentinal  tubes ;  6,  an  erratic  growth  of  irregularly 
formed  and  unusually  transparent  dentin;  c,  line  of  the  growth  of  dentin  from  the  floor  of  the  pulp 
chamber — the  growth  from  other  directions  is  so  perfectly  regular  as  to  leave  no  markings;  d,  margin 
of  the  cavity  of  decay:  e,  a  bundle  of  cylindrical  forms  of  calcific  material  extending  down  into  the  root 
canal.     These  extended  to  the  apex  of  the  root.     (Black.) 


The  arsenical  method  may  be  used  after  a  preliminary  general  anes- 
thesia and  bulb  removal,  or  may  even  be  used  against  an  obdurate 
pulp  canal  filament. 

Symptoms. — The  large  majority  of  pulps  die  under  arsenic  with  but 
little  pain.  Sometimes  throbbing  pain  results,  passing  into  a  heavy 
fulness  as  congestion  supervenes.     If  too  great,  the  pulp  should  be 


408  TREATMENT  AND  FILLIXC  OF  ROOT  CANALS 

uncovered  and  bled  slightly,  then  a  sedative  should  l)e  applied,  iodin 
used  as  a  conntcrirritant  upon  the  ^um,  and  pulp  death  awaited.  Ordin- 
arily the  pain  passes  away  as  the  pulp  heeonies  more  fully  congested. 
Apical  irritatif)n  may  result  and  may  be  ignored  if  slight,  or  if  severe  be 
treated  in  the  same  way  as  the  pulp  irritation.  A  guard  to  prevent 
overocclusion  is  sometimes  useful. 

Accidents  from  Arsenical  Applications. — These  are  avoidable,  and 
therefore  only  occur  as  the  result  of  carelessness.  In  very  doubtful 
cases,  if  a  "pocket"  cannot  be  employed  the  patient  should  be  seen  after 
one  or  two  days  for  observation  of  the  condition  of  the  gum.  It  is  better 
that  no  escharotics  have  been  applied,  as  confusion  may  result.  The 
signs  of  arsenical  necrosis  at  this  time  are  a  turgid,  purplish,  or  sloughing 
gum  festoon,  and  if  present  this  should  be  freely  cut  away  and  the 
arsenical  application  should  be  removed  from  the  cavity. 

Any  exposed  alveolar  process  should  be  scraped  and  the  parts  should 
l)e  kept  aseptic  with  hydrogen  dioxid.  Applications  of  dialyzed  iron  or 
10  per  cent,  silver  nitrate  solution  will  arrest  further  necrotic  action  j)y 
forming  insoluble  arsenites  of  the  respective  metals. 

If  the  tooth  be  lost  the  alveolus  .should  be  burred  away  to  ti.ssue 
capable  of  healthy  graiuilation.  If  bone  l)ec()ine  necrotic  it  usually  is 
self-limited,  even  though  it  be  considerable.  The  part  should  be  treated 
as  above  and  the  exfoliation  awaited  with  this  a.ssurance. 

The  condition  of  the  roots  as  to  calcification  or  decalcification  may  be 
determined  l)y  consulting  Figs.  432  and  433;  and  resorbed  or  incom- 
plete teeth  .should  not  have  arsenic  placed  in  them,  as  the  arsenic  may 
pass  through  the  existing  end  of  the  root. 

Special  Methods  of  Preparing  Pulps  for  Removal. — When  in  the  course  of 
extirpation  a  vital  apical  remnant  is  found,  carbolic  acid  may  be  instilled 
into  it  wnth  a  fine,  well-sharpened  Swiss  or  other  smooth  steel  broach. 
The  canal  is  flooded  with  the  phenol  and  the  broac-h  is  to  be  repeatedly 
but  gently  yet  progressively  thrust  into  it,  carrying  with  it  some  car- 
bolic acid.  Forcibly  pressing  the  phenol  into  the  pulp  filament  under 
a  mass  of  unvulcanized  rubber,  as  in  cocain  pressure  anesthesia  tech- 
nique, will  usually  desen.sitize  the  filament  and  facilitate  its  removal 
without  hemorrhage. 

A  hot  Evans'  root  drier  may  be  quickly  thrust  into  it.  This  does 
not  necessarily  give  much  pain.  Tightly  packing  a  thread  of  cotton 
saturated  with  carbolic  acid  against  such  a  filament  and  leaving  for  a 
few  days  will  sometimes  induce  thrombosis  and  death  of  the  pulp. 

\Mien  a  tooth  has  been  fractured  or  excised,  or  when  the  pulp  is  fully 
and  widely  exposed  in  a  single  root,  a  Portuguese  toothpick  finely  whit- 
tled and  previously  soaked  in  carbolic  acid  may  be  quickly  thrust  into 
it,  thus  "knocking  out"  or  crushing  out  its  vitality,  so  suddenly  as  to 
prevent  much  painful  response.  If  the  removal  of  the  stick  does  not 
bring  the  pulp  with  it,  it  should  be  broached  out. 


method:^  of  pulp  removal 


409 


Devitalization  of  Pulps  in  Temporary  Teeth. — All  of  the  anesthetic 
measures  are  as  applicable  to  temporary  teeth  as  to  the  permanent  ones 
if  the  little  patient  will  tolerate  their  application. 


t 

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ooo 

If  the  child  present  an  exposed  pulp  in  a  tooth  the  roots  of  which  are 
not  resorbed,  arsenic  much  diluted  may  be  applied  for  twenty-four 


410 


TREATMENT  AND  FILLING  OF  ROOT  CANALS 


hours  and  then  be  removed,  the  i)ulp  being  then  allowed  to  die.  When 
roots  are  resorbed  it  is  better  to  cap  the  pulp  with  Jodo-Formaf,'en 
cement,  or  if  necessary  apply  a  pellet  of  cotton  wet  with  i)hen()l,  then 
touched  to  iodoform  and  seal  in  with  temporary  stopping,  making  a 
slight  pressure.  This  may  remain  a  week  or  more  and  be  renewed  if 
necessary. 

Darby  has  used  cantharides,  yV  grain  in  carbolic  acid,  with  success. 
It  nuist  be  carefully  sealed,  as  strangury  is  a  possibility. 


THE  EXTIRPATION  OF  THE  PULP 

After  the  pulp  is  prepared  for  removal  or  the  patient  is  anesthetized 
free  access  to  all  parts  of  the  pulp  cavity  and  canals  must  be  obtained. 
This  is  usually  best  accomplished  by  an  opening  made  in  direct  line 
with  the  axis  of  the  pulp  canal.  In  general  terms  this  involves  for 
sound  teeth  an  opening  upon  the  lingual  surface  of  incisors  and  cuspids 
and  upon  the  occlusal  surface  of  bicuspids  and  molars. 


FiQ.  434 


FiQ.  435 

a  c 


Fia.  43f;   Fic.  437 


Pig.  438 


Fig.  439 


Fig.  440 


Fig.  441 


This  access  may  consist  of  a  new  opening  or  an  extension  of  a  ca\ity, 
or  at  times  the  cavity  and  canal  may  simply  be  made  continuous. 

When  a  cavity  of  decay  exists  the  pulpal  wall  should  be  i)er- 
forated  and  a  large  bud  bur  should  be  used  to  cut  away  the  dentin 
overhanging  the  pulp  cavity.     It  is  usually  necessary  to  extend  the 


THE  EXriltPATION  OF   THE  I'l^LP 


411 


cavity  in  the  central  occlusal  direction,  so  as  to  pennit  direct  access  to 
each  canal  (Figs.  A\\^  to  440). 

When  a  tooth  crown  would  be  irreniediahly  weakened  hy  such  a 
course,  a  slight  indirectness  is  permissible  when  flexible  cleansers  can  be 
used  instead  of  drills.  This  leaving  of  tooth  structure  should  be  done 
with  judgment.  The  canals  must  be  cleansed.  In  cavity  approaches  the 
outer  wall  of  the  pulp  ca\'ity  should  be  cut  away  to  permit  an  obtuse- 
angled  approach  rather  than  a  right-angled  one  (Figs.  439,  441,  A). 
All  pulp  cavity  corners  should  be  burred  to  a  shape  that  obviates  reten- 
tion of  pulp  debris,  the  subsequent  decomposition  of  which  would  lead 
to  discoloration.  The  opening  shown  in  Fig.  437  is  faulty  for  this  reason, 
and  is  better  if  extended  more  toward  the  incisal  edge,  making  an  oblong 
opening  with  rounded  ends. 

Fig.  442 


Kerr  or  Downie  broaches.     Various  finer  sizea  of  these  broaches  and  reamers  may  be  had. 
They  should  have  accurate  taper. 


In  sound  teeth  the  entrance  to  the  canal  is  made  with  a  small  spear 
drill,  after  the  enamel  has  had  a  "  spot"  made  in  its  surface  with  a  sharp 
dentate  bur.  This  centres  the  spear  drill  and  prevents  its  slipping  about. 
After  it  has  entered  the  pulp  cavity  dentate  biu-s  are  used  to  enlarge 
the  opening  to  the  desired  size  and  shape.  A  sawing  motion  creates 
more  rapid  clearance  and  cutting  of  tooth  tissue. 

One  should  not  always  suppose  that  the  spear  drill  will  drop  into  an 
appreciable  pulp  cavity.  The  careless  driving  of  a  drill  into  a  tooth  may 
cause  a  perforation.  Secondary  dentin  or  a  large  nodule  and,  in  pre- 
viously treated  teeth,  zinc  phosphate  may  occupy  the  pulp  chamber. 
Therefore,  when  doubt  arises,  open  well  that  portion  of  tooth  or  filling 


412 


TREATMENT  AND  FILLINC,   OF  ROOT  CANAES 


which  has  been  drilled  throu^di  and  note  the  conditions,  then  ^o  ahead 
carefully.  In  oj)ening  a  located  pulp  chainher  with  burs  a  bud  bur  is 
very  useful,  })ut  all  burs  once  placed  throu^di  the  drill  hole  and  into  the 
l)ulp  chamber  must  be  used  laterally  or  the  heel  of  the  bur  used  with  an 
outward  sweep  toward  the  occlusal  aspect  for  the  sake  of  safety. 

The  canal  (or  canals)  is  now  to  be  explored,  and  if  of  operable  size  a 
Donaldson  cleanser  or  barbed  broach  is  passed  to  the  canal  ajK'x,  twisted 
so  as  to  engage  its  teeth  with  the  pulp  substance,  and  the;  i)nlp  extirpated. 


Fia.  443 


Fig.  44(5 


Fig.  417 


Fio.  444 


Fig.  445 


% 


u 


Dr.  Donaldson's  pulp-canal  nleansora. 


Dr.    Donaldson's  spring-tempered    nerve  bristles. 


If  there  be  any  difficulty  in  finding  the  canals  after  this  preparation, 
by  reason  of  the  broach  catching  on  the  edge  of  the  orifice,  the  mouth 
of  the  canal  should  be  made  continuous  with  the  wall  of  the  pulp  chamber 
by  means  of  a  small  bud  l)ur.  The  wall  then  leads  the  broach  into  the 
root  lumen. 


TllIC  EXTIRPATION  OF  THE  PULP  413 

III  single-rooted  teeth  with  finer  apic(^s  a  fine  Kerr  engine  root  reamer 
(Fig.  442)  may  be  passed  by  hand  to  the  apieal  portion  of  the  root  and 
gently  rotated.  It  is  then  mounted  in  the  hand  jMece,  passed  gently 
to  the  apex,  slightly  withdrawn,  and  then  operated  by  engine  power. 
It  is  pressed  lightly  laterally  to  enlarge  the  canal  slightly.  The  next 
larger  size  is  then  used  in  like  manner,  and  finally  the  larger  admissible 
sizes.  This  gives  a  beautifully  tapered  canal  f(jrm  useful  in  canal  filling 
and  for  the  adaptation  of  dowels.  The  pulp  is  simultaneously  removed, 
generally  being  churned  out  of  the  root,  and  danger  of  false  openings 
is  avoided.  A  final  exploration  and  apical  scraping  may  be  given  with 
a  fine  Donaldson  cleanser  (P'igs.  443  to  446)  and  the  pulp  cavity  cornefii 
rounded  out  with  burs. 

This  technique  is  only  admissible  in  cases  of  openings  in  line  with  the 
pulp  axis.  Those  almost  in  such  line  may  have  the  flexible  sizes  of  Kerr 
reamers  so  used,  all  apexward  pressing  and  reaming  to  be  done  by  hand 
at  first.  When  general  anesthesia  is  employed  it  is  better  to  open 
roughly,  then  pass  a  fine  Donaldson  cleanser,  which  has  been  previously 
dipped  in  carbolic  acid  and  laid  aside  in  readiness,  to  the  apex  of  the 
root  canal.  It  is  given  a  few  turns  to  engage  the  pulp,  and  the  latter  is 
lifted  away.    The  other  work  is  to  be  done  upon  return  to  consciousness. 

As  the  Kerr  broaches  and  reamers  are  made  of  a  variety  of  forms, 
it  should  be  stated  that  only  those  which  have  a  gradual  taper  from 
point  to  shank  can  be  relied  upon  to  satisfactorily  carry  out  this  tech- 
nique. In  these  the  successive  sizes  follow  one  another  without  danger 
of  perforation  of  the  canal  walls. 

It  is  sometimes  better  to  drive  a  fine  hand  Kerr  broach  to  the  canal 
apex,  and,  if  the  engine  broach  be  not  permissible,  to  continue  with  the 
different  sizes  of  hand  broaches.  One  soon  obtains  a  familiarity  with  the 
canal  curve  and  size  when  working  with  the  hand,  which  gives  confidence 
and  safety  when  later  working  with  engine  power. 

In  molar  teeth  and  upper  first  bicuspids,  after  the  pulp  chamber  has 
been  prepared,  the  canals  are  to  be  located  with  a  fine  smooth  broach 
or  a  Kerr  broach.  The  finest  root  reamer  is  then  used  by  hand  and 
gently  twisted  and  forced  apexward  into  each  canal  in  turn.  The  next 
smaller  is  then  used.  As  these  canals  are  normally  somewhat  curved, 
only  flexible  forms  should  be  used  unless  the  larger  size  follows  readily 
the  rather  curved  canal  made  by  the  previous  one.  Following  this, 
Donaldson  cleansers  are  operated  by  hand  to  scrape  the  sides  and 
inequalities  of  the  somewhat  flattened  canals  which  the  reamers  have 
not  reached  (Figs.  448  to  451).  When  the  finest  Kerr  reamer  does  not 
explore  the  canal  properly,  owing  to  constrictions,  a  drop  of  50  per  cent, 
sulfuric  or  pure  lactic  acid  in  water  is  introduced  into  the  canal  and 
a  smooth,  fine,  spring-tempered  Swiss  broach  is  used  to  gently  enlarge 
it  by  drawing  it  back  and  forth  in  the  canal.  Then  a  fine  Donaldson 
cleanser  is  to  be  used  in  the  same  manner;  later  the  larger  sizes  are 


414 


TRKATMKST  AND  FILLIXd  OF  ROOT  CANALS 


usod.  If  IVasiblo,  the  Kerr  reamers  may  now  })e  used,  wlieii  direet 
aeeess  is  liad.  If  the  access  be  indirect  tlie  Donaldson  cleansers  only 
should  be  used. 

Some  o])erators  prefer  the  use  of  the  alloy  kalium-natriuni,  used  on 
the  broach  as  a  means  of  facilitating  the  opening  of  the  canals.  If  acid 
be  used  it  should  be  neutralized  with  sodium  bicarbonate  or  sodium 


Fig.  448 


Fio.  449 


Fig.  450 


Fiu.  431 


dioxid.  The  improved  Gates-Glidden  drill  (Fig.  452)  has  some  use  in 
the  enlargement  of  canals  the  lumen  of  which  has  l)een  determined  by 
the  above  methods.  They  should  not  be  used  for  the  preliminary 
opening  of  fine  canals,  as  they  tend  to  form  false  channels  in  the  side  of 
the  canals  which  constantly  catch  even  fine  bristles  and  may  render  a 
canal  into  a  form  even  less  advantageous  than  that  it  already  possesses. 
The  canal  filament  of  pulps  in  molars  and  upper  first  bicuspids  may  be 


THE  EXTIRPATION  OF  THE  I'VLP  415 

lifted  away  with  barbed  broaches  or  cleansers  if  the  canals  are  hirge, 
but  it  is  ordinarily  a  waste  of  time  to  attempt  it  in  the  finer  canals,  as 
the  other  work  must  be  done  in  the  apical  regions. 

This  technique  is,  as  a  rule,  best  carried  out  under  rubber  dam,  to 
prevent  the  septic  contamination  of  canals  by  entrance  of  infected  saliva; 
but  if  this  be  impossible  it  is  wise  to  sterilize  the  mouth  and  napkin  it, 
and  to  place  a  drop  of  cai  bolic  acid  or  formocresol  in  the  canals  and  con- 
tinue the  work  under  antiseptic  precautions. 

It  is  wise  to  ha^"e  the  patient  first  brush  the  teeth,  using  soap  or  a 
tooth  paste  or  powder.     After  application  of  the  dam  or  napkin  the 
cavity  is  cleansed  of  the  debris  of  decay 
if  any  be  present.    Then  the  cavity  is  to  fig.  452 

be  wiped  out  with  phenol-camphor.  Next 
the  application  of  cocain,  etc.,  is  made. 
Before  entering  the  pulp  chamber  or  just 
after,  a  drop  of  formocresol  is  to  be 
placed  on  the  field  of  operation  and  a 
clean  bur  used  to  enter  the  pulp  cavity. 
The  debris  is  removed,  the  canals  located,  i^p,„^ed  Cates-Giidden  nerve-canai 
and  a  fresh  drop  of  formocresol  placed  driii  for  engine  work. 

before  continuing  with  the  canal  w^ork. 

As  the  napkins  become  wet  they  may  be  removed,  the  cavity  douched 
with  a  jet  of  warm  water,  the  patient  rested  for  a  moment,  and  then  the 
napkins  are  reapplied,  the  cavity  dried,  and  the  operation  repeated. 
The  napkins  may  be  renewed  without  disturbing  the  treatment,  but  it  is 
often  desirable  to  w^ash  out  the  debris,  and  the  rest  is  often  agreeable 
to  the  patient. 

The  scraping  of  the  canals  removes  the  possible  remnants  of  pulp 
tissue,  odontoblasts,  etc.,  adhering  to  the  dentin  walls,  and  also  a  part 
of  the  wall  with  the  large  ends  of  the  fibrils.  All  these  are  decomposable 
media,  may  become  septic,  and  are  wisely  removed. 

The  final  removal  of  all  pulp  debris,  coagulated  blood,  etc.,  is  best 
done  with  a  fine  Donaldson  cleanser  moved  to  and  fro  in  the  canal  wath 
one  hand,  while  with  the  other  a  stream  of  w^arm  water  is  gently  intro- 
duced by  means  of  a  IMoffat  syringe.  A  large  cottonoid  roll  or  a  napkin 
may  be  held  by  the  patient  or  assistant  to  absorb  the  excess  of  moisture 
when  the  rubber  dam  is  in  position. 

The  carrying  out  of  canal  treatment  involves  a  knowledge  of  the 
topographical  anatomy  of  the  teeth  and  their  pulp  canals.  As  an  aid 
to  this  Figs.  453,  454,  and  455  are  introduced,  showing  the  normal 
outlines  of  the  teeth  and  their  pulp  chambers.  Fig.  455  shows  the 
appearance  and  locations  of  the  pulp  canal  openings  at  their  coronal 
ends.  It  is  to  be  borne  in  mind  that  the  roots  are  not  always  normal  in 
shape,  as  shown  in  Figs.  456  to  489,  and  that  various  degrees  of  lack  of 
development  or  resorption  may  cause  the  root  canals  to  be  unusually 


il6  TREATMENT  AM)  FlLUXd  OF  ROOT  CANALS 


DESCRIPTION    OF    FICJS.   4.-);^,  4r)4  AND   455 

Fig.  453.— Fig.  3  gives  in  contrast  a  sectional  viuw  of  deciduous  and  permanent  upper  leetb 
divided  through  their  lateral  diameters. 

Fig.  4,  a  sectional  view  of  the  corresponding  lower  teeth  divided  through  their  antero-posterior 
diameters,  a,  h,  c  represent,  respectively,  the  deciduous  and  permanent  front  incisors  in  con- 
trast: d,  e,/,  the  lateral  incisors;  g,  h,  i,  the  canines;  A-,  deciduous  molars,  upper  and  lower;  and 
I,  m,  the  successors  to  the  deciduous  molars,  the  bicuspids  ;  v,  o  represent  ijcrmanent  molars. 
c,f,  i,  rn,  0  have  dotted  lines  indicating  the  thickness  of  enamel  removed  by  wear,  atrophy  of  the 
cementum,  and  reduction  in  the  size  of  the  pulp  due  to  progressive  calcification,  these  changes 
being  incident  to  old  age. 

Fig.  454  represents  in  Fig.  1,  letters  a  to /i  and  ato_^,  the  longitudinal  or  vertical  sections  of 
the  sixteen  upper  teeth,  showing  the  labio-palatal  diameter  of  the  pulp  chamber  and  canal  in 
crown  and  roots,  the  section  of  the  molars  being  through  the  anterior  buccal  and  palatal  roots, 
while  the  bicuspids  d  e  and  d_e  illustrate  the  result  of  such  a  compression  of  the  root  as  to 
divide  the  pulp  chamber  into  two  canals— a  condition  which  so  frequently  exists  in  these  flattened 
roots.  The  double-lettered  series,  dd  to  hh  and  d_d  to  h_h,  represent  in  the  molars  a  section 
through  the  posterior  buccal  and  the  palatal  roots,  from  which  is  quite  readily  recognized  the 
slightly  greater  lateral  diameter  of  the  pulp  chamber  in  the  crown  and  the  larger  canal  in  the  poste- 
rior buccal  root  over  that  in  the  anterior  buccal  root,  while  the  bicuspids  lettered  eedd  and  ddee 
illustrate  a  modified  pulp  chamber  and  canal,  with  bifurcation  of  the  root  in  one,  these  being  cut 
through  a  different  axis  or  plane  from  the  single-lettered  series. 

Fig.  2,  letters  a  to  ft  and  a  to  ^^,  represent  the  sixteen  lower  teeth  with  the  section  through 
their  long  diameters,  as  in  the  upper  series.  These  incisors  illustrate  the  compressed  or  flat- 
tened condition  of  their  roots  in  contrast  with  the  cylindrical  character  of  the  roots  of  the  upper 
incisors,  while  the  bicuspids  d  e  and  rf_e  illustrate  the  singleness  of  their  pulp  chamber  and  the 
cylindrical  condition  of  their  roots  as  in  contrast  with  the  flattened  or  compressed  condition  of 
the  roots  of  the  upper  bicuspids.  The  molars  /,  ^r,  h  and  f,  g.  h  represent  sections  through  the 
anterior  root,  illustrating  its  compressed  condition  and  divided  pulp  chaml)er  in  the  first  and 
second  molar,  and  a  somewhat  flattened  one  in  the  anterior  root  of  the  third  molar ;  //,  g  g  ,hh 
and  //,  g  g,  h  h  represent  the  single  and  cylindrical  pulp  chamber  in  the  posterior  root  of  the 
lower  molars,  while  hh,  cc  and  aa.bh  represent  the  incisors  and  canines  of  the  same  series,  with 
modified  pulp  chambers  arising  from  modified  development. 

Fig. 455.— Fig.  1,  from  rt  to /t  and  a  to _/i,  represents  the  upper  teeth,  with  transverse  or  horizon- 
tal section  through  the  base  of  the  pulp  chamber  in  the  crown,  viewing  the  entrance  to  the  canals 
of  the  several  roots,  while  the  same  letters  in  Fig.  2  represent  the  lower  series  in  the  same 
manner. 

Fig.  ?>  represents  the  upper  teeth,  with  the  transverse  or  horizontal  section  made  below  the 
largest  diameter  of  the  pulp  chamber  and  through  the  canals  after  they  have  diverged  from  the 
central  chamber,  but  before  the  roots  into  which  they  run  have  in  the  molars  bifurcated. 

Fig.  4  in  like  manner  represents  the  lower  series,  well  illustrating  the  flattened  or  compressed 
condition  of  the  canal  in  anterior  roots  of  the  molars  and  the  division  of  the  chamber,  as  is  fre- 
(l\icntly  found  in  the  roots  of  the  lower  incisors. 

The  letters  a  a,  b  b,  c  c,  d  d,/f,  dd  a.nde_e  (Fig.  3)  represent  the  relative  shai)es,  whether  circu- 
lar, oval,  or  flattened,  of  the  pulp  canal  in  the  roots  of  the  upper  central  and  lateral  incisors, 
the  canines,  the  first  and  second  bicuspids,  and  the  first,  second,  and  third  molars,  while  the 
same  letters  in  Fig.  4  represent  the  relative  shapes  of  the  pulp  canal  in  similar  teeth  in  the 
lower  series. 

»  These  figures  are  taken  from  v.  Carabelli's  Anatomic  des  Mandts. 


Fia.  453 


-^C^ 


^C« 


27 


(417D 


Pio.  454 


(418) 


THE  EXTIRPATION  OF  THE  PULP 


KiG.  455 


420 


TREATMENT  AND  FILLINa  OF  ROOT  r.lAM/>,S' 


open  or  short  with  the  treatment  eomphcated  by  the  i)re.senee  of  vital 
tissue  at  the  root  ends.     In  a  general  way  it  nia>  he  stated  that  mueh 


Fig.  456 


Fig.  4r)9 


Fig.  462 


Fig.  457 


llpper  lateral  incisors.      (<  )ttuleiigiii.) 
Fiu.  400 


Upper  canines. 
Fig.  463 


FiQ.  4()1 


Fig.  464 


Upper  first  bicuspids. 


Fia.  465 


FiQ.  466 


h  a 

Upper  second  bicuspid. 


Upper  fir.st  molar. 


res' 


■;orbed  roots,   as  indieated  by  the  age  in  decichions  teeth,  or  largely 
incomplete  roots,  as  indicated  by  the  age  in  permanent  teeth,  indicate 


THE  EXTIRPATION  OF  THE  PULP 


421 


a  pulp  C'api)infi;  {)|)(>rati()U  ratlicr  than  cxtiri)ati()ii;  in  the  permanent 
teeth,  to  i)orniit  better  root  formation.  If  unavoidable,  one  must  do 
the  best  possible  (see  Figs.  432  and  438). 


Fia.  407 


Fiu.  408 


Fi<!.  4(;<» 


Upper  molar. 

Fio.  470 


Fig.  471 


Upper  second  molars. 
Fin.  472 


Fig.  473 


Fig.  474 


Fig.  475 


Upper  molars.     (Ottolengui.) 
Fig.    476 


Upper  third  molars. 


In  the  penetration  and  enlargement  of  canals  the  larger  and  straighter 
canals  may  be  cleansed  thoroughly  to  the  apex,  but  in  very  fine  and 
tortuous  roots  (Figs.  456  to  489)  the  operator  is  often  confronted  with 
the  option  of  taking  the  chances  of  perforation  by  forcing  further 


422 


TliKATMEST  AND   FllJJXd  OF  ROOT  CANALS 


entrance  or  of  Icaxiii^^  .some  (loiil)lfiil  apical  jxx'tioii  unclcaiisfd.  'i'iie 
decision  should  he  that  the  daiif^er  of  perforation  is  the  greater  evil,  and 
agents  of  a  nnnnrnifying  character  should  he  cini)loyed  to  render  any 


Fig.  477 


0,1 


Fig.  478 


Ijower  infisors  aiid  ciinine. 


Fig.  480 


Lower  fir.st  biouspid. 
Fig.  4S2 


Fig.  48.-5 


Fio.  479 


Fig.  481 


Lower  second  bicuspid. 
Fig.  484 


Lower  hicuspid.s. 


Lower  first  molars. 


such  filament  into  a  state  lessening  the  danger  of  subsequent  putre- 
faction. 

The  writer  regards  the  use  of  formocresol  (equal  parts  of  'AT  per  cent. 


THE  EXT  Hi}' AT  I  ON   OF   Till':  PUI.P 


42n 


aciuoous  forinaldcliyd  solution  and  <'resol)  as  especially  \alual)lc  where 
immediate  root  fillinji;  is  not  indicated.  If  the  patient  be  of  nervous  and 
irritable  type  this  may  l)e  dihited    to  5  or  10  ])er  cent,  formaldehyd 


Flo.  486 


Fi<i    4S7 


Lower  first  molar,  iiiiniaturo. 


strength  by  the  use  of  cresol  or  camphophenique  without  impairing  its 
value.     Often  the  full  strength  may  be  used  on  cotton  as  a  temporary 


Fio.  4S8 


Fig.  489 


Lower  second  molar. 


Lower  third  molar. 


Fig.  490 


dressing.     This  hardens  any  remaining  pulp  and  also  probably  the 
fibrils  in  the  tubules.    It  also  permits  the  apical  tissue  to  heal  and  resume 
its  normal  sensitivity  when  the  pulp  has  been  entirely  removed,  which 
is   of    value    in    determining  the  extent   to 
which  pressure  may  be  applied  in  filling  the 
canals. 

In  a  few  cases  in  which  cervical  cavities 
obliterate  the  canal  or  cause  annoying  ap- 
proach to  it,  it  is  desirable  to  remedy  the 
condition.  In  such  case  the  canals  are 
opened  as  usual  and  enlarged,  and  the  cavity 
prepared  with  suitable  retentions  for  filling. 
The  last-used  reamer  is  then  to  be  placed  in 
the  canal  and  the  filling  inserted.  The  fill- 
ing is  then  supported  by  pressure  while  the 
reamer  is  slowly  twisted  to  the  right  and 
withdrawn,  leaving  a  canal  through  the  fill- 
ing. This  may  be  done  with  amalgam  or 
with    zinc   phosfate  if   a   later    removal   be 

required.  If  the  root  be  much  weakened,  a  tapering  dowel  may  be 
cemented  through  the  crown  and  canal,  thus  attaching  the  root  to  the 
crown  more  firmlv. 


Method  of  restoring  lost  oanal 
eontinuit.v.  The  cavity  should 
have  more  retention  form  than 
shown. 


424  TREATMENT  AND  FILLING  OF  ROOT  CANALS 


ACCIDENTS  IN  CANAL  OPENING. 

The  chief  accidents  tliat  may  occur  are  the  perforation  of  the  root 
wall  and  the  breakino;  of  the  instruments  used.  If  the  technique  laid 
down  be  carefully  followed  the  danf]:or  of  perforation  is  j)ractically  elimi- 
nated. In  fact,  the  greatest  danger  is  the  penetration  and  enlargement 
of  the  apical  foramen.  To  avoid  this  the  Kerr  reamers  should  always 
be  passed  to  the  apex  of  the  canal  by  hand  or  while  the  reamer  is  not 
revolving.  It  is  then  withdrawn  a  trifle  and  revolved,  and  one  may 
always  judge  the  distance  the  reamer  was  withdrawn.  Accidents  are 
usually  the  result  of  thoughtless  forward  pressure  of  reamers  and  drills, 
and  care  will  reduce  this  to  a  minimum.  Sometimes  one  must  take  the 
chances  with  the  Kerr  engine  reamer.  When  doubt  exists  as  to  canal 
locations,  the  desiccation  of  the  pulp  chamber  is  of  great  assistance  by 
bringing  them  into  view,  and  if  secondary  deposits  exist  one  should 
always  use  a  small  bud  bur  and  keep  well  within  the  limits  of  the  dentin 
of  a  root  w^hile  gently  seeking  a  canal  lumen. 

Frequent  exploration  should  follow  gentle  advances,  and,  as  a  rule, 
the  canal  will  be  found  of  fairly  normal  size  just  beyond  the  point  of 
constriction.  In  some  cases  50  per  cent,  sulfuric  acid  should  be 
sealed  against  the  suspected  canal  and  the  operation  deferred  to  another 
sitting. 

If  a  perforation  be  accidentally  made  it  should  be  covered  as  in  any 
case  of  perforation  (which  see). 

Always  one  should  be  able  to  diagnosticate  such  an  opening,  and 
arsenic  should  never  be  applied  to  such.  Cases  of  extensive  necrosis  have 
occurred  from  carelessness  in  this  direction.  The  breakage  of  broaches 
is  largely  avoidable  through  the  use  of  new  instruments  and  by  adhering 
to  the  rule  of  using  the  smaller  sizes  until  the  canals  are  sufficiently 
enlarged  to  permit  the  use  of  larger  sizes,  and,  in  case  of  engine  reamers, 
of  starting  the  power  with  the  reamer  loose  in  the  canal. 

The  engine  broach  seems  to  be  of  better  temper  than  the  engine 
reamer. 

Accidents  of  this  sort  usually  occur  with  barbed  instruments  of  the 
Donaldson  cleanser  type,  especially  when  used  with  force.  Sulphmic 
acid  tends  to  disintegrate  the  broach,  so  that  lactic  acid  is  often  better 
used  with  it,  or  the  alloy  of  sodium  and  potassium  with  a  smooth  broach 
will  open  the  canal  so  that  the  cleanser  will  not  bind.  If  it  bind  it  should 
be  grasped  with  the  thumb  and  finger  and  given  a  straight  pull. 

While  avoidance  is  far  better  than  the  application  of  the  remedy,  if 
the  accident  occur,  the  broach  should  be  remoxed  if  possible. 

If  lying  loosely  in  the  canal  a  new  cleanser  may  be  passed  to  one  side 
of  it  and  then  be  pressed  against  it.  It  should  engage  the  barb  and  jig 
it  out. 


CASES  IN  WHICH  THE  PULP  IS  DEAD  425 

Cotton  wrapped  on  a  small  Swiss  broach  may  he  pressed  down  at 
one  side  of  the  l)roken  broach  and  its  fibers  made  to  engage  its  barhs. 

^Moving  the  broach  back  and  forth,  while  suh'uric  acid,  sodium 
dioxid,  or  sodium  and  potassium  is  about  it,  will  sometimes  loosen  it. 
One  may  sometimes  drill  to  one  side  of  a  broken  instrument  with  a  Kerr 
engine  broach  in  order  to  more  readily  engage  it  with  a  barbed  instru- 
ment. If  very  loose  a  magnetized  probe  will  attract  it  and  draw  it 
out. 

If  the  broach  be  tightly  fixed  in  the  canal,  sodium  chlorid,  tincture  of 
iodin,  sulfuric  acid,  aqua  regia,  or  25  per  cent,  pyrozone  may  be  sealed 
in,  in  the  hope  of  chemically  disintegrating  it. 

The  head  of  a  Gates-Glidden  drill  or  Kerr  reamer  is  treated  in  the 
same  manner. 

If  any  broach  be  irremovable,  iodoform  paste  or  embalming  paste 
should  be  packed  over  it  and  sealed  in,  in  order  to  keep  the  parts  per-' 
manently  sterile.  In  a  septic  case  the  formocresol  treatment  should 
precede  such  root  filling  (see  p.  401). 

For  root  filling,  see  p.  456. 


CASES  IN  WHICH  THE  PULP  IS  DEAD 

There  are  several  classes  of  cases  requiring  root  canal  treatment  in 
which  the  pulp  is  completely  necrosed  when  the  patient  presents,  and  in 
all  but  one  of  these  the  pulp  is  in  a  putrefactive  condition.  Therefore 
the  consideration  of  the  treatment  may  be  taken  up  under  the  following 
headings : 

1.  Cases  in  which  the  pulp  is  in  a  state  of  dry  gangrene. 

2.  Cases  in  which  the  pulp  is  in  a  state  of  moist  gangrene  but  no 
evidence  of  acute  pericementitis  is  present. 

3.  Cases  in  which  the  pulp  is  in  a  state  of  moist  gangrene  and  subacute 
or  acute  septic  pericementitis  is  present. 

4.  Cases  in  which  the  pulp  is  in  a  state  of  moist  gangrene  and  a 
fistula  upon  the  gum  or  other  part  is  evidence  that  there  has  been  an 
acute  abscess  which  has  passed  into  the  chronic  or  discharged  state. 

Dry  Gangrene. — By  dry  gangrene  of  the  pulp  is  meant  its  total  death 
under  aseptic  conditions,  and  the  absorption  of  its  moisture,  leaving  a 
tough  shrivelled  mass  (Fig.  491).  This  condition  is  very  rare  as  a  spon- 
taneous occurrence,  but  no  doubt  has  been  frequently  induced  by  the 
application  to  pulp  stumps  of  mummifying  preparations  containing 
paraformaldehyd,  alum,  tannin,  or  zinc  chlorid;  indeed,  this  is  the 
intent  of  the  so-called  mummifying  pastes.  The  conditions  favorable 
are:  (1)  Pulp  death  from  some  aseptic  cause,  such  as  the  h\'peremia 
resulting  from  a  blow  on  a  sound  tooth.  (2)  The  constriction  of  an  apical 
foramen,  as  by  hypercementosis,  the  result  of  thread  biting  or  other 


426 


THEATMEXT  AXD  FILIJSG  OF  ROOT  CANALS 


Pigment. 


Fio.  4'.)2 

Sulfur  +  liiiiioglobiii. 


mild  irritation  of  the  jx'ricciiKMitiiiii,  {.))  The  cxliaiistioii  of  the  |ml|)  (hie 
to  yecoiidary  dentin,  which  may  protect  it  from  subsequent  infection. 
(4)  The  cappiuf^  of  the  pulp  with  agents  having  a  mummifying  and  also 
antiseptic  action  (which  includes  such  treatment  of  pulp  stumps). 
The  former  practice  of  using  zinc  oxychlorid  and  the  present  use  of 
Jodo-Formagen  may  have  such  action  if  the  pulp  undergoes  irritation 
and  death  in  spite  of  the  cap. 

The  tooth  may  have  a  good  color,  the  dentin  will  })e  insensiti\'e,  but 
without  odor,  and  there  will  be  no  odor  or  fluid  in  the  pulp  canal.  The 
final  diagnosis  can  only  ])e  made  when 
the  pulp  is  found  in  the  shrivelled  state. 
This  is  of  very  rare  occurrence,  odor 
almost  always  being  present. 

Treatment. — The  tooth  should  be 
opened  and  the  pulp  Hfted  away  under 
the  antiseptic  influence  of  a  formal- 
dehyd  solution.  The  canals  are  to  be 
opened  as  in  any  case  of  vital  pulp. 

Moist  Gangrene  Without  Pericementitis. 
— The  death  of  the  pulp  through  venous 
hyperemia  or  inflammation  leaves  it  full 
of  moisture.  If  saprophytic  organisms 
gain  entrance,  it  undergoes  decoraposi- 


FiG.  491 


CO2.  NH,; 
H2O  and  H3S 

Aromatic  and 
fafty  prod- 
ucts. 

Ptomainx. 


Peptones. 


Dry  gansrone  of  the  pulp:  I'X,  pulp  nodule;  DP, 
shrivelled  pulp.  (From  a  specimen  of  pulp  extracted 
intact  iu  this  condition.) 


Diagram  illustrating  the  more  complete 
decomposition  f)f  the  pulp  at  its  coronal 
end. 


tion  through  putrefaction  or  fermentation  into  a  series  of  compounds 
simpler  in  chemical  structure  than  its  own  proteid  compounds.  Albu- 
minous substances  putrefy  with  the  formation  of  (1)  peptones,  and  (2) 
ptomains  or  animal  alkaloids,  such  as  putrescin,  neuridin,  and  cadaverin, 
which  are  stated  to  l^e  capable  of  pus  formation  in  vital  tissue  when  free 
from  bacteria.  Next,  nitrogenous  bases,  leucin,  tyrosin,  and  the  amines ; 
also  organic  acids.  Next,  aromatic  products,  indol,  phenol,  cresol,  and 
finally  hydrogen  sulfid,  ammonium  sulfid,  carbon  dioxid,  and  water. 
The  end  products  account  for  the  presence  in  decomposing  pulps  of 


CASES  JDl    WHICH   THE   I'ULP  IS   DEAD 


427 


Fig.  493 


j^B-'P- 


g'»-lg.i  -- 


malodorous  gases  and  moisture  (Fi^-  H)2).  "Fermentation  and  putre- 
faction can  only  occur  where  the  fimgi  concerned  live  and  the  extent 
of  decomposition  is  conditioned  })y  the  number  of  fungi.'" 

In  its  clinical  aspect  a  putrefactive  pulp  is  of 
the  yellow  color  of  sloughing  tissue  with  a  reason- 
ably tough  consistence,  less  than  the  normal, 
however,  which  indicates  recent  gangrene  witii 
begiiming  decomposition.  It  next  passes  into  a 
jelly-like  consistence,  and  finally  into  gases  and 
water.  Naturally  the  greatest  number  of  fungi 
will  have  by  multiplication  invaded  that  end 
nearest  the  source  of  infection,  the  mouth  or 
cavity  of  decay,  while  the  more  consistent  portion 
of  the  pulp  will  exist  at  the  apex.  This  is  exactly 
what  is  found  clinically  in  cases  seen  at  the  right 
time.  Of  course,  total  decomposition  into  gases 
and  water  may  occur,  so  that  the  canal  may  appear 
empty  or  nearly  so,  yet  odor  can  generally  be 
found,  as  even  tubular  contents  decompose  and 
the  tooth  structure  is  saturated  with  the  end 


Fig.  4!)4 


Fig.  495 


II 


1  ■  ■  tm 


Sector  of  a  cross-section 
from  a  diseased  root:  a, 
oementum;  6,  stratum  gran- 
ulosum;  c,  very  narrow  and 
finely  branched  tubules;  d, 
penetration  of  bacteria  into 
tubules.      X  150.     (Miller.) 


Dentin  from  the  root  of  an  ab- 
scessed tooth,  showing  the  penetra- 
tion of  cocci  to  a  depth  of  about 
yV  mm.  (o-iffn  in.),  the  side  a-h 
bordered  upon  the  canal.  X  1000. 
(Miller.) 


Skiagraph  of  unfilled  root 
canals  with  large  mass  of  fill- 
ing material  built  in  over 
them.     (Price.) 


Ziegler. 


428  TREATMENT  AM)  FILLIXG  OF  ROOT  CANALS 

products  (Fif,'.  4!)."^).  As  tiu-  i)iilp  dccomijoses,  tlio  II.S  (•()iiil)iii<'S  with 
the  Nil,  of  proteid  origin  to  form  NHJIS  or  (XHJ.,S,  which  in  turn 
combines  with  the  iron  of  the  liem()gIol)in,  forming  Fe.S,  which  (hirkens 
the  tissue.  Tartiul  gangrene,  the  apical  portion  of  a  ])uli)  heing  vital, 
is  sometimes  seen,  and  sometimes  one  canal  filament  will  undergo 
decom])osition  and  even  produce  an  abscess,  while  another  or  two 
other  filaments  remain  vital. 

As  these  gangrenous  pulps  often  produce  apical  abscesses,  they  must 
contain  pyogenic  organisms;  still,  abscess  and  ulceration  in  which  the 
pulp  body  undergoes  j)utrefactive  dec(miposition,  with  formation  of 
pus,  is  not  necessarily  gangrene,  but  rather  a  necrobiotic  process. 

Arkovy  found  that  i)ulps  infected  with  the  Bacillus  gangrenre  pulpfE 
in  pure  culture  would  undergo  total  gangrene  without  sui)puration, 
while  when  infected  with  mixed  cultures  or  even  pleomorphic  forms  of 
the  Bacillus  gangra-iuw  pulpa'  chronic  pulpitis  was  produced.  If  the 
mixed  culture  contains  pyogenic  bacteria  it  is  })lain  that  the  chronic 
pulpitis  may  be  suppurative. 

Gangrenous  pulps  do  not  necessarily  produce  abscesses  at  once,  but 
often  clinical  history  shows  that  a  year  or  two,  or  even  more,  may  elapse, 
though  as  short  a  time  as  two  or  three  weeks  has  sometimes  been  suffi- 
cient. In  one  case  of  a  boy,  aged  ten  years,  the  time  between  a  capping 
of  a  bleeding  pulp  with  Jodo-Formagen  and  the  presence  of  a  fistula 
upon  the  gum  was  but  two  weeks.  It  was,  howe\-er,  in  a  temporary 
first  molar,  and  the  cement  covering  the  cap  was  found  to  be  loose. 

The  forcing  of  gangrenous  pulp  tissue  by  instrumentation  into  apical 
tissue  generally  results  in  an  abscess,  even  when  extraneous  bacteria 
are  presumably  not  introduced. 

The  irritating  substances  in  a  decomposing  jiulp  are  presumably  the 
bacteria,  the  ptomains,  and  the  expanding  gases. 

Many  decomposed  puljjs  produce  no  pain,  but  in  these  cases  the  gases 
may  escape  via  dentinal  tu})ules  and  leaks  about  fillings  (Fig.  495). 

Clinically,  putrefactive  pulps  may  be  found  in  sound  teeth,  in  filled 
teeth,  and  in  teeth  the  ])nlp  cavities  of  which  are  op(Mi  to  the  oral  fluids 
either  actually  or  through  the  medium  of  open  tubules  in  the  dentin 
over  them,  or  in  apical  portions  of  poorly  cleansed  or  partly  filled  canals. 
A  cotton  dressing  having  a  bad  odor,  or  an  apparently  empty  apical 
portion  of  canal  or  a  leaky  gutta-percha  canal  filling  associated  with  a 
bad  odor,  e\en  though  the  pulp  has  been  successfully  removed,  have  a 
similar  pathology.  There  is  little  difference  in  principle  between  putre- 
factive serum  or  tubule  contents  and  a  putrefactive  pulp.  Any  of 
these  may  cause  abscess  or  remain  quiescent. 

Si/mptomatolog}/. — The  symptoms  are  opacity  of  the  tooth  evident 
to  the  eye  or  nt)ted  by  transmitted  light,  discoloration  of  varying 
degrees,  odor  and  discoloration  of  the  dentin  in  a  cavity. 

There  is  a  lack  of  response  to  cutting,  thermal  and  electric  tests. 


CASES  IN   WHICH  THE  PULP  IS  DEAD  429 

Sometimes  ;i  bad  taste  due  to  leakage  is  present.  Looseness,  tenderness 
to  pereussion,  ineipient  and  acute  abscess,  and  a  clironic  fistula  are 
evidences  of  ])ericemental  irritation. 

Pain  to  heat,  while  usually  indicative  of  pulp  irritation,  also  sometimes 
occurs,  and  is  explainable  upon  the  same  theory  of  the  expansion  of 
gases  against  vital  tissue — in  this  case  the  apical  tissue.  These  symp- 
toms are  all  explained  by  the  pathology  of  the  conflition. 

Treatment. — The  pulp  being  presumably  infected,  all  quiescent 
gangrenous  pulps  or  putrefactive  conditions  under  any  conditions, 
discovered  indicate  a  similar  treatment,  namely,  first  disinfection  to 
remove  or  kill  bacteria  which  might  cause  an  abscess  and  at  the  same 
time  to  destroy  the  chemical  nature  of  the  gases  and  ptomains.  After 
this  the  canals  are  to  be  thoroughly  opened. 

Three  substances  are  preeminent  in  this  direction — (1)  formaldehyd, 
(2)  nascent  oxygen,  (3)  iodin  or  its  derivatives. 

At  the  present  writing  no  substance  equals  formaldehyd,  because  of 
its  rapid  diffusion  through  all  canals,  tubules,  and  even  abscess  tracts. 

The  first  and  best  treatment  consists  in  opening  the  pulp  cavity  and 
gently  removing  the  bulk  of  decomposed  pulp  from  the  pulp  chamber 
and  canals,  care  being  employed  to  avoid  forcing  any  putrid  material 
into  the  apical  tissue  by  broaching  or  plunging  of  the  bur.  Also,  no 
bacteria  should  be  introduced  from  outside.  The  opening  should  not 
be  too  freely  made,  and  should  be  funnelled  or  countersunk  outwardly 
to  secure  the  seal  against  being  plunged  into  the  pulp  cavity  in  masti- 
cation (Fig.  496). 

This  being  done,  the  canals  are  dried  with  cotton  and  hot  air,  and  a 
small  pellet  of  cotton  saturated  with  formocresol  or  10  per  cent,  aqueous 
formaldehyd  solution  is  to  be  placed  in  the  pulp  chamber.  Any  that 
has  come  in  contact  with  the  orifice  should  be  removed  with  alcohol. 
The  orifice  is  then  dried  and  a  small  piece  of  dry  spunk  placed  o^'e^ 
the  application,  but  not  so  as  to  interfere  with  the  seal.  Quick-setting, 
adhesive,  hydraulic  cement  is  now  flowed  into  the  orifice,  air  bubbles 
being  avoided  by  flowing  it  in  with  an  instrument.  A  bit  of  paraform 
accomplishes  the  same  purpose  as  the  solution,  namely,  the  liberation 
of  formaldehyd  gas. 

When  opportunity  for  self-relief  seems  proper,  as  when  the  operator 
is  leaving  his  practice  for  a  short  time,  or  may  otherwise  be  inaccessible, 
hot  temporary  stopping  may  be  used  and  the  patient  instructed  as  to 
the  proper  procedure  to  obtain  relief.  An  ordinary  pin  crooked  at  the 
point  by  striking  it  across  any  hard  surface  will  serve  to  pick  out  the 
stopping  and  cotton.  In  all  cases  tight  coverings  must  be  made,  as 
the  object  is  to  concentrate  the  action  of  the  formaldehyd  gas  upon 
the  canal  and  tubular  contents. 

In  some  cavities  it  is  well  to  make  the  covering  first,  as  done  for  arsenic 
(see  Fig.  430),  and  to  seal  the  dressing  in  with  a  further  addition  of 


430  TREATMENT  AM)  FILLING  OF  ROOT  CASALS 

cement  or  temporary  stopping,'.    The  latter  does  not  permit  mastication 
like  the  former. 

If  there  be  a  broad  cavity  extending  beneath  the  gum,  it  is  well  to  press 
the  gum  away  with  cotton  pellets,  then  to  form  the  cavity  and  open  the 
canal  orifices.  Then  a  retention  at  the  cervical  portion  of  the  cavity 
should  be  made,  even  if  it  be  necessary  to  drill  a  series  of  pits  along  it 
with  a  No.  1  bur.  Spunk  is  now  placed  over  the  pulp  canals  and 
quick-setting  amalgam  is  to  be  permanently  built  in  at  this  part  of  the 
ca\ity.  When  set  the  spunk  is  withdrawn,  formocresol  in  cotton  is 
inserted  instead  of  the  spunk,  and  the  covering  completed  with  cement. 
The  amalgam  is  finished  as  far  as  practicable  at  the  one  sitting  and  the 
case  dismissed.  At  future  sittings  rubber  dam  may  be  applied  and  the 
canal  work  done  (Fig.  497). 

Fig.  496  l'"'^-  ^'-'^ 


a,  cutlun  and  formocresol;   h,  spunk,  Cen'ical  wall  built  up  with  amalgam  to  permit 

c    cement.  canal  sterilization  and  treatment. 

Formocresol  consists  of  equal  parts  of  37  per  cent,  aqueous  formal- 
dehyd  solution  and  cresol,  which  combine  well. 

According  to  Buckley,  the  formaldehyd  not  only  acts  as  a  germicide, 
but  combines  with  the  ammonia  of  ammonium  sulfid  to  form  uro- 
tropin  and  with  hydrogen  sulfid  to  form  methyl  alcohol  and  sulfur. 
The  cresol  is  supposed  to  act  upon  the  fatty  compounds,  changing  them 
into  a  compound  resembling  lysol.  Thus,  antiseptic  substances  are 
formed  from  poisonous  ones.  Formaldehyd  is  so  efficacious  in  the 
writer's  hands  that  it  has  displaced  other  methods  in  his  practice.  All 
other  methods  of  disinfection  produce  results  less  certain  than  those 
jjroduced  by  it  and  are  more  cumbersome,  thereff)re  they  will  be  here 
dispensed  with.  While  this  is  true  for  a  great  majority  of  the  ca.ses,  occa- 
sionally a  patient  is  met  with  whose  tissues  do  not  tolerate  formalde- 
hyd well.  Formocresol  then  should  be  reduced  to  a  5  per  cent,  solution 
with  cresol  or  phenol-camphor,  and  in  some  cases  abandoned  for  more 
sedative  antiseptic  remedies,  such  as  eugenol  or  phenol-camphor  with 
menthol. 

This  first  dressing  may  be  left  for  from  twenty-fom-  hours  to  a  week, 
or  longer  if  the  patient  is  comfortable. 


CASES  IN    WIIICJI   THE  I'lJLP  IS   DEAD  431 

At  the  second  .sittiutj;  the  rubber  chini  is  to  be  applied  and  the  canal 
oj)ening  thoroughly  made  under  formocresol  influence,  just  as  though 
the  pulps  were  vital,  the  technique  differing  in  no  respect.  A  second 
dressing  is  introduced  into  the  canals.  Whether  this  shall  carry  the  full 
strength  formocresol  or  it  shall  be  modified  by  the  addition  of  cresol 
or  phenol-camphor  depends  upon  the  history  of  any  irritation  or  perfect 
comfort  as  a  result  of  the  first  application.  The  ol)ject  of  a  second 
dressing  is  to  determine  whether  the  odor  (gases)  has  been  discharged 
from  the  tubules.  "When  the  dressing  has  absence  of  putrefactive  odor, 
no  pus  can  be  detected,  and  the  patient  is  comfortable,  the  canal  is  ready 
for  filling.  Less  than  this  result  is  too  soon,  and  delay  beyond  this  is  a 
loss  of  time. 

When  one  pulp  filament  is  gangrenous  and  another  vital,  the  treat- 
ment is  the  same,  it  being  the  writer's  experience  that  formocresol 
loosely  placed  is  not  incompatible  with  ulcerated  pulps,  and,  indeed,  is 
an  excellent  dressing  for  suppurative  pulps  when  modified  to  a  3  to  5 
per  cent,  strength.    Later,  the  vital  portion  is  appropriately  removed. 

When  apical  pericementitis  of  a  subacute  nature  is  present  on  a 
filled  tooth,  as  when  a  tooth  shows  some  looseness  and  tenderness,  with 
some  injection  of  the  gum,  all  faulty  root  canal  fillings  should  be 
removed  with  barbed  broaches,  cleansers,  or  root  reamers,  and  the  case 
is  then  resolved  into  one  of  moist  gangrene  and  treated  accordingly. 

If  a  cotton  root  filling  be  found  it  sometimes  allows  the  broach  to 
tear  loose.  In  such  case  a  Kerr  broach  is  dri^'en  into  it  to  create  a 
central  opening,  after  which  the  fibers  become  engaged  by  the  barbed 
broach. 

Eucalyptol  may  be  used  to  soften  gutta-percha  root  canal  fillings, 
and  at  times  the  smallest  Kerr  or  Downie  broach  is  to  be  bibevelled  at 
its  end  and  used  as  a  drill  cutting  its  way.  Oxychlorid  and  other 
cement  fillings  may  have  50  per  cent,  sulfuric  acid  or  strong  ammonia 
water  applied  to  them  to  assist  in  breaking  up  the  bond  of  the  cement 
by  chemically  destroying  either  the  zinc  oxid  or  the  acid.  The  drill 
will  tamp  the  fluid  into  the  cement  and  cut  the  cement  at  the  same 
time. 

All  root  fillings  of  cement  nature  are  apt  to  be  faulty  when  used  as 
such,  because  the  air  in  the  canal  prevents  ingress,  though  it  may  appear 
to  be  well  filled.  This  fact  is  of  importance  in  diagnosis  in  filled  teeth, 
giving  evidence  of  chronic  pericementitis,  i.  e.,  there  is  probably  an 
unfilled  portion  of  root  canal  containing  putrefied  pulp  or  serum. 

It  is  a  weakness  of  good  operators,  if  not  of  all,  to  think  that  their 
individual  canal  fillings  are  perfectly  made.  The  writer  was  once  asso- 
ciated with  a  most  conscientious  man,  and  possesses  a  gutta-percha 
canal  filling  of  his  in  a  molar  now  successful  for  twenty  years.  On  one 
occasion  he  declared  that  he  had  filled  perfectly  a  canal  of  an  upper 
second  bicuspid  because  the  material  had  been  felt  by  the  patient  as  it 


4;i2  THEM' M lis r   AM)  FILI.ISd  OF  ROOT  CANALS 

miclu'd  the  ai)ex.  Two  weeks  later  the  tooth  was  extracted,  thoufjh 
eoTiifortal)le,  for  orthodontic  purposes.  Its  well-opened  canal  was  empty 
for  a  (jnarter  of  an  inch  at  the  ajx'x. 

To  remove  })ins  from  roots  a  bihevelled  Kerr  broach  may  })e  driven 
into  the  cement  or  dentin  about  it  and  the  drifts  united.  The  pin  may 
often  be  forced  to  one  side  and  then  jiss^^d  loose.  If  there  be  sufficient 
pin  extending  above  the  face  of  the  root  a  "pin  puller"  may  be  used. 
If  the  pin  cannot  be  loosened  it  must  be  drilled  out  bodily.  A  sharp 
round  bur  should  be  used  to  countersink  the  end  of  the  pin,  and  then 
by  the  aid  of  oil  it  is  cut  into  shavings.  Freciuent  desiccation  and  exami- 
nation to  observe  the  presence  of  a  metal  remnant  is  necessary  to  avoid 
the  accident  of  jxTforation. 


DENTO-ALVEOLAR  ABSCESS 

The  term  dento-alveolar  abscess  is  a  comprehensive  one,  meant  to 
include  all  those  cases  of  abscess  having  a  beginning  in  the  pericementum 
of  a  tooth  and  extending  into  the  alveolar  process  or  nuixillary  bone, 
and  which  ha\e  their  origin  in  septic  matter  located  in  or  introduced  by 
way  of  the  root  canal  of  a  tooth.  It  includes  the  anatomically  specialized 
abscesses  of  such  origin,  e.  g.,  apical  abscess,  beginning  at  the  apex  of 
the  tooth,  or  lateral  abscess,  beginning  in  a  perforation.  The  description 
of  the  pathology  of  apical  abscess  serves  for  the  other.  It  may  be,  but 
should  not  be,  made  to  include  pericemental  abscess  due  to  pyorrhea 
alveolaris.     (See  Chapter  XV.) 

Causes. — An  apical  abscess  is  a  septic  and  suppurative  pericementitis 
beginning  in  the  pericementum  at  the  apex  of  a  tooth  (the  apical  tissue). 
The  pyogenic  organisms,  the  Diplococcus  pneumonia,  the  Staphylo- 
coccus pyogenes  aureus  and  albus,  and  the  Streptococcus  pyogenes 
are  the  probable  causes  of  the  infection,  as  examination  has  show^n 
(Schrier).  These  may  exist  in  a  gangrenous  pulp,  be  introduced  upon 
instruments  uncleansed  from  a  previous  infection,  or  contaminated  by 
contact  with  saliva  or  unclean  hands  at  the  time  of  operation,  or  the 
infection  may  have  crept  in  by  way  of  leaks  in  cavity  or  canal  fillings. 
In  apparently  sound  teeth  the  infection  either  enters  by  way  of  cracks 
or  open  tubules  at  the  necks  of  teeth  or  beneath  such  cracks  or  in  a  pyor- 
rhetic  case  through  the  apical  foramen  by  way  of  the  ej)ithclial  debris  of 
the  sheath  of  Hertwig  constituting  the  resting  cells  of  the  peridental 
membrane.  Entrance  by  way  of  the  blood  is  a  more  remote  possibility. 
AVhatever  be  the  avenue  of  entrance,  infection  occurs  and  produces  the 
phenomena  of  suppurative  inflammation  (Fig.  498).  There  is  arterial 
hyperemia  followed  by  a  venous  hyperemia  due  to  a  collection  of  leuko- 
cytes along  the  walls  of  the  small  veins;  emigration  of  leukocjiies  and 
exudation  of  lymph  into  the  perivascular  tissue  occurs.    In  the  area  of 


DEN  TO- A  L  VEOLA  li  A  BSCESS 


433 


acute  and  active  iulluniiiuition  btusis  occurs.  The  exudate,  leukocytes, 
and  tissue  cells  are  liquefied  by  the  peptonizing  action  of  the  bacterial 
ferments  into  pus.  Coincidently  these  processes  produce  much  swelling, 
which  causes  the  pushing  of  the  tooth  from  its  socket,  which  in  turn 
causes  its  overocclusion  with  its  antagonists,  and  the  mechanical  irrita- 
tion from  this  becomes  an  a<lded  cause  of  irritation.  The  inflamma- 
tory process  spreads  out  from  the  central  focus  of  pus  formation,  there 
being  around  the  pus  a  zone  of  active  inflammation  or  stasis;  about 
this  one  of  a  lesser  degree  of  inflammation,  also  full  of  leukocytes;  about 
this  an  area  of  arterial  hyperemia  or  the  first  stage  of  inflammation, 
and  around  this  normal  tissue.  These  areas  are  not  sharply  defined, 
but  merge  into  one  another  (Fig.  498,  A,  D,  E,  F). 


Fig.  498 


Showing  the  morbid  anatomy  of  septic  apical  pericementitis  (acute):  A,  pus;  B,  area  of  dying 
leukocytes;  C,  septic  matter  in  root  canal;  D,  excavation  of  process  (osteomyelitis;  area  of  lesser 
inflammation);  E,  swollen  periosteum  and  gum,  hyperemic  or  normal;  F,  alveolar  bone  in  a  state  of 
hyperemia:  G,  pericementum  at  edge  of  necrosis. 


In  this  way  the  contiguous  area  of  the  alveolar  bone  and  the  soft 
tissues  of  the  face  become  involved  in  the  process,  being  discolored  and 
tumefied  in  proportion  to  the  extent  of  the  pus  formation  and  the 
inflammatory  reaction  thereto. 

From  a  clinical  viewpoint  the  abscess  is  incipient  when  inflammation 
of  the  apical  tissue  next  to  the  foramen  is  profound  and  pus  formation 
has  just  begun  (Fig.  498). 

The  apical  abscess  is  considered  to  be  in  the  first  stage  while  the 
pus  is  still  in  the  apical  tissue,  in  the  second  stage  while  the  pus 
28 


434 


TREATMENT  AND  FILUSG  OF  ROOT  CANALS 


is  involving  the  bone  marrow  in  the  alveohir  bone  (Fig.  499j,  in  the 
third  stacje  when  the  pus  is  in  the  soft  tissues  overlying  the  bone 
(Fig.  oOO),  and  as  chronic  when  the  pus  has  discharged,  forming  a  fistulous 


Fio.  499 


Fit;.  500 


Acute  abscess  in  second  si  age.  Tooth 
opened  at  6  for  treatment,  making  a  blind 
abscess.     (Black.) 


Acute  aveolar  abscess  of  a  lower  incisor  in 
the  third  staee,  with  pus  cavity  between  the 
bone  and  the  periosteum:  a,  pua  cavity  in 
the  bone;  6,  pus  between  the  periosteum 
and  bone;  c,  lip;  d,  tooth;  e,  tongue.  (Black.) 


Fig.  501 


Fig.  502 


Absce.'Mi  upon  lower  third  molar,  showing 
the  usual  paths  of  pus  exit,  .1  and  li. 


y. 


.\bscess  upon  palatal  root  of  an  upper  molar  discharging 

at  the  neck  of  the  tooth. 


tract  or  sinus  (Fig.  501),  or  has  dischargetl  via  the  canal  (Fig.  499). 
These  areas  are  the  ones  successively  involved,  and  as  the  pus  pene- 
trates them  the  character  of  the  iinolvement  of  the  superjacent  struc- 


DENTO-AL VEOLA K  ABSCESS 


435 


tures  changes  t()  the  more  severe  form.  Thus  with  ])us  formation 
inci])ient  there  is  normal  tissue  at  the  gum  surface  (Fig.  4ns).  With  more 
advanced  pus  formation  in  the  apical  tissue  the  normal  gum  surface 
changes  to  hyperemic  tissue,  then  inflamed  tissue,  then  pus-containing 


Fig.  504 


%^^ 


Dento-alveolar  abscess  at  the  root  of 
a  superior  incisor,  discharging  into  the 
nose:  a,  large  abscess  cavity  in  the 
bone;  b.  mouth  of  fistula  on  the  floor  of 
nostril;  r,  lip;  d.  tooth.      (Black.) 

Fig.  505 


Dento-alveolar  abscess  at  the  root  of  an 
upper  molar  discharging  into  the  antrum  of 
Highmorc:  a,  abscess  cavity  in  the  hone;  b, 
mouth  of  fistula  on  the  floor  of  the  antrum;  c, 
pus  in  the  antral  cavity.      (Blacli.) 

Fig.  506 


Chronic  abscess  of  upper  incisor,  showing  tendency 
of  pus  to  progressively  destroy  pericementum,  owing 
to  the  influence  of  gravity. 


Chronic  abscess  upon  lower  tooth, 
showing  tendency  of  pus  to  sink  into  the 
substance  of  the  lower  maxilla,  owing  to 
the  influence  of  gravity. 


tissue  tumefied  according  to  the  amount  and  progress  of  the  pus  toward 
the  surface  (Fig.  500).  The  same  theory  applies  to  the  swelling  of  the 
face. 

While  the  abscess  usually  discharges  through  tlie  alveolar  plate  and  gum ' 
tissue  either  buccally  or  lingually  (Figs.  501  and  507),  it  does  not  always 


43() 


TREATMKST  AM)  FllJJXd  OF  ROOT  CANAFS 


do  SO,  hut  may  discharge  througli  the  tissues  of  the  face  (Figs.  509  to 
514),  or  into  the  antrum  (Fig.  504),  nasal  cavity  (Fig.  503),  the  floor 
of  the  mouth  or  pharynx  (Fig.  513),  or  even  dissect  its  way  between  the 
nuiscles  of  the  neck  and  discharge  at  the  clavicle. 


Fig.  507 


I'iG.  508 


W&f 


Chre.nic  apical  abscess  iliscliarKinK  tlirough  the  hard 
palate  and  threatening  to  discharge  labially. 


Chronic  abscess,  showing  dinudatiun 
of  apex  of  root  (o  to  b),  with  deposits  of 
calculi  (a)  upon  cementum. 


Sometimes  it  has  a  partial  discharge  by  way  of  the  root  canal,  either 
naturally  or  as  the  result  of  the  abortion  of  it  through  the  intentional 
opening  of  the  root  canal.  Sometimes  it  dissects  its  way  along  the 
pericemental  tract  and  discharges  at  the  neck  of  the  teeth  (Figs.  501 
and  502).    An  abscess  on  a  root  perforation  near  the  gingival  margin 


Fig.  510 


Scar  caused  by  alveolar  abscess  discharging 
on  the  face.      (Black.) 


Operation  for  the  remedy  of  scar  on  tlie  face 
caused  by  alveolar  abscess.      (Black.) 


is  ^  cry  i)rone  to  do  this,  although  it  may  discharge  through  the  gum  over 
the  perforation.  ]\Iore  than  is  often  supposed  the  })us  formation  is 
subacute  and  the  pyogenic  bacteria  inacti\e,  so  that  tiie  i)us  is  semi- 
encysted  in  a  fibrous  enclosure  or  sac  with  organized  and  thickened 


DENTO-A L  \  KOLA  R  A JiSCESS 


4:57 


walls.  The  abscess  may  rcniaiii  in  this  state  for  some  time  or  dexelop 
an  acute  form  (Fig.  515). 

The  adjoiniui!:  teeth  usually  have  more  or  less  pericementitis,  and  the 
pulps  may  become  hyperemic  in  consequence  and  be  more  responsi\^e 
to  thermal  changes.  In  some  cases  the  adjoining  teeth  are  profoundly 
involved. 

There  is  unquestionably  a  great  difference  in  the  severity  of  abscesses 
in  different  individuals,  some  having  great  tissue  reaction  and  painful 


FiQ.  511 


FiQ.  512 


Chronic  dento-alveolar  abscesa 
of  the  root  of  the  lower  incisor, 
with  abscess  cavity  passing 
through  the  body  of  the  bone  and 
discharging  on  the  elcin  beneath 
the  chin:  a,  very  large  abscesa 
cavity;  b,  mouth  of  the  fistula. 
(Blacli.) 


Fistula  passing  down  through  the  body  of    the   lower 
maxilla.     (Black.) 


Fig.  513 


Abscess  with  tortuous  sinus,  opening  upon  the  face:    .4, 
tissue  of  cheek;  B,  floor  of  mouth;  C,  abscess  tract. 


resistance  to  pus  advance,  or  length  of  duration  and  wide  involvement 
of  the  soft  tissues,  while  others  have  an  abscess  reach  to  the  formation 
of  a  fistula  with  little  or  no  pain  or  facial  swelling.  The  average  time 
required  is  from  twenty-four  hours  to  three  days.  The  anemic,  cachectic, 
and  strumous,  as  well  as  those  having  a  syphilitic  or  tuberculous  infection 
or  history,  are  more  liable  to  produce  abscesses  because  of  their  general 
lessened  resistance,  and  their  pulps  die  more  readily  under  conditions 
in  which  the  pulps  of  others  would  live.  In  no  case,  however,  can  these 
conditions  alone  produce  abscess.     The  exciting  cause  must  be  present. 


438 


'I  UKATMENT  AM)  FILIJ.\(I  OF  ROOT  (A\AJ.S 


Ik;.  514 


When  these  j)re(lisposing  eonditioiis  exist,  liowever,  aiifl  abscess  suj)er- 
veiies,  the  n'hitively  low  resistjuice  of  the  tissues  may  i)ermit  extensive 
(lestruetion  both  as  the  result  of  the  aeute  and  chronic  forms. 

There  are  fre(iueiitly  manifestations  of  systemic  intoxication  from 
the  toxins  formed  durin<;  the  suppuration  and  absorbed  from  the 
inflammatory  focus.  Thus  in  ordinary  acute  cases  there  is  some  fever, 
often  ushered  in  with  a  chill  or  chilliness.  The  pulse  increases  in  volume 
and  tension,  is  full,  hard,  and  fi'cquent.  The  tongue  is  coated,  the 
breath  fetid,  the  bowels  constipated.     The  patient  is  weakened  and 

made  irritable  by  pain  and  the  attendant 
loss  of  sleep  and  appetite.  In  the  infec- 
tion by  Streptococcus  pyogenes  there  is 
danger  that  these  may  change  into  the 
more  profound  symptoms  of  septicemia, 
i.  e.,a  soft,  frequent  pulse,  repeated  chills, 
diarrhea,  clammy  skin,  general  depression, 
and  a  disordered  ner\ous  s\'stem.  Also 
in  such  an  infection  there  is  more  cellulitis 
and  less  pus  formation. 

Diagnosis. — While  the  symptoms  usually 
indicate  a  clear  diagnosis,  this  is  not 
always  the  case.  A  tooth  may  huve  a 
perfect  color  sometimes  when  examined 
by  the  transmitted   rays   of  an   electric 

Fig.  515 


Chronic  ficnto-alveolar  abscess  at  tlie 
root  of  a  lower  inci.sor,  with  a  fistula  di.-*- 
chargiiig  ou  the  fare  under  the  chin:  o, 
abscess  cavity  in  the  bone;  b,  b,  b,  fistula 
following  in  the  periosteum  down  to  the 
lower  margin  of  the  body  of  the  bone  and 
discharging  on  the  skin.      (lilack.) 


Small  abscess  upon  roots  of   an  vipiwjr  molar. 


mouth  lamj);  usually,  however,  it  has  at  least  an  opaque  appearance. 
Of  two  pulpless  teeth  surrounded  by  a  zone  of  inflammation,  the  most 
tender  is  the  one  affected,  although  both  may  be  involved  at  once. 

A  pericemental  abscess  due  to  pyorrhea  alveolaris  is  located  laterally, 
as  a  rule,  and  wdiile  it  involves  swelling  of  the  gum,  usually  has  not 
much  facial  involvement.  Usually  also  it  is  connected  with  a  pyorrhea 
pocket. 

An  abscess  may  be  found  in  connection  with  a  broken  root  or  carious 
bone. 


DENTO-ALVEOLAR  ABSCESS  439 

This  is  usually  of  the  chronic  variety  iu  case  of  necrosed  (^)r  <';irious 
bone,  with  one  or  more  fistulie  leading  to  the  diseased  area. 

A  sinus  usually  leads  from  the  occlusal  direction  to  a  broken  root. 
If  the  gum  has  healed  in  this  direction  the  abscess,  if  not  acute,  may 
be  found  with  a  sinus  upon  the  side  of  the  gum.  An  impacted  tooth 
or  odontome  may  have  an  abscess  associated  with  it.  If  chronic  the 
probe  leads,  as  a  rule,  to  enamel  or  the  peculiar  body.  A  cyst  may  be 
associated  with  a  sinus. 

An  abscess  sometimes  forms  beneath  the  flap  of  gum  overlying 
a  tliii'd  molar.  This  begins  as  an  ulceration  of  the  under  side  of  the 
flap,  but  the  pus  burrows  between  the  tooth  and  the  gum,  and  when  well 
confined  may  develop  laterally,  causing  the  formation  and  at  least 
partial  retention  of  a  quantity  of  pus  in  the  tissues  of  the  cheek.  This 
condition  more  nearly  simulates  the  lateral  abscess  associated  with  a 
pyorrhea  pocket,  and  as  by  extension  it  sometimes  involves  the  tonsil 
the  case  may  be  mistaken  for  an  amygdalitis. 

The  direction  pus  may  take  is  often  determined  by  gra\nty,  but  the 
resistance  of  certain  tissues  may  cause  the  pus  to  seek  the  easiest  path. 
Thus,  by  discharging  into  the  antrum  it  goes  rather  counter  to  gravity. 
In  such  cases  as  discharge  into  the  antrum  there  is  liable  to  be  a  collec- 
tion of  pus  in  that  cavity  which  may  cause  destruction  of  the  mucous 
membrane  and  bone.  This  condition  is  known  as  empyema  of  the 
antrum.  The  sudden  subsidence  of  an  acute  abscess  upon  a  tooth 
located  beneath  the  antrum  should  create  a  suspicion  of  discharge  into 
that  sinus.  If  a  fine  probe  can  be  passed  an  unusual  length  into  a  root 
canal  it  indicates  this  form  of  sinus  in^'olvement. 

Upon  a  sound  tooth  the  evidences  of  pulp  vitality  or  death  should 
be  observed,  i.  e.,  the  pink  translucency  or  the  opacity  to  light  trans- 
mitted by  an  electric  mouth  mirror,  or  the  thermal  tests  of  great  heat 
or  cold  applied. 

If  the  tooth  be  filled,  or  the  dentin  uncovered  at  any  point,  the 
interrupted  electric  current  or  the  galvanic  current,  with  the  anode 
applied  to  the  tooth,  the  cathode  at  the  hand,  produces  a  slight  shock. 
In  case  of  exposed  dentin,  dryness  may  interfere  with  the  test.  When 
a  sinus  is  present  a  soft  silver  probe  may  often  be  passed  toward  the 
tooth  affected. 

As  a  rule,  a  sinus  lies  distally  to  the  affected  tooth.  Taken  in  con- 
junction with  the  symptoms,  the  history,  appearance,  or  reactions  to 
tests  afford  a  certain  diagnosis.  If  a  tooth  be  opened  upon  suspicion, 
evidence  of  vital  dentin  (sensitivity)  should  be  carefully  observed,  as 
the  drill  is  made  to  penetrate  it.  A  timid  patient  will  often  uninten- 
tionally confuse  pericemental  tenderness  with  the  pain  of  sensitive 
dentin. 

In  very  doubtful  cases,  as  when  molars  have  deep  amalgam  fillings, 
or  pins  have  been  placed  in  root  canals,  or  gold  crowns  cover  the  natural 


440  TREAT M EX r  AXD  FILLIXC!  OF  ROOT  CAXALS 

crown,  one  should  oht.iiu  a  rii(lio«;ra|)li  or  <'ls(»  perforate  the  filhiig  or 
crowns  carefully  and  ol)ser\'e  the  conditions  of  sensitivity,  odor,  vtv. 
In  teeth  filled  having  a  history  of  canal  fillings  it  is  wise  to  suspect  an 
imperfect  or  unattempted  root  fillin<^. 

Prognosis. — In  a  vast  majority  of  cases  the  prognosis  is  good  if  the 
patient  submit  to  the  necessary  therapeutics.  If  these  can  be  thoroughlx' 
applied  and  regeneration  of  tissue  induced  the  case  may  be  considered 
cured. 

Treatment. — In  the  initial  inflammation  and  first  stage  of  pus  forma- 
tion in  an  acute  abscess  the  treatment  should  })e  abortive. 

This  consists  of  oi)ening  the  pulp  canals  hy  remo\'ing  any  obstruc- 
tions to  its  connection  with  the  surface  of  the  enamel,  whether  this  be 
enamel,  a  filling,  a  root  canal  filling,  etc.  The  one  possible  exception  is  a 
fixed  and  irremovable  crown. 

This  must  often  be  done  under  counterpressure,  as  the  pericementum 
will  be  responsive  to  pressure.  A  thread  knotted  about  the  neck  of  the 
tooth  may  be  gently  pulled  by  the  patient  as  the  operator  drills,  or  a  bit 
of  modelling  compound  may  be  moulded  over  the  opposite  surfaces  of 
several  teeth,  chilled,  and  held  by  the  finger  of  the  operator.  Holding  a 
tooth  with  the  finger  and  thumb  or  pressing  a  tooth  firmly  in  one  direction 
will  often  sufficiently  steady  it  against  the  drill  pressure  or  shaking. 

The  point  of  access  may  be  through  the  dentin  of  a  cavity,  by  partial 
or  total  removal  of  a  filling  and  dentin  perforation;  by  perforation  of 
the  enamel  and  dentin,  or  in  unusual  cases,  where  no  better  can  be  done, 
by  perforation  of  the  cementum  and  dentin  at  the  neck  of  the  tooth. 

The  manner  of  drilling  is  described  on  page  411.  When  the  opening 
is  made  the  canal  should  be  washed  with  an  antiseptic,  while  a  barbed 
cleanser  is  gently  passed  to  and  fro  until  all  debris  is  removed,  and  if 
possible  the  apical  foramen  cleared  so  that  gases  and  pus  may  be  dis- 
charged ma  the  canal.  The  presence  of  blood  in  the  canal  is  evidence  of 
a  complete  discharge  of  the  abscess  contents.  This  usually  gives  prompt 
relief  after  a  possible  preliminary  throbbing.  The  writer  finds  it  best 
to  leave  the  tooth  open  in  the  severe  acute  eases. 

In  order  to  lessen  the  irritation  of  occlusion  upon  the  affected  tooth 
a  "guard"  made  of  rubber  dam  should  be  api)lie(l  to  a  slightly  distant 
tooth.  This  consists  of  a  strip  of  rubber  dam  about  two  inches  long 
and  as  wide  as  the  distance  from  the  lingual  to  the  buccal  cervix  over  the 
occlusal  face  of  the  selected  tooth.  This  is  then  folded  into  a  pad  the 
width  of  the  occlusal  face.  A  needle  threaded  with  floss  silk  is  then 
passed  down  through  the  right  proximal  corner,  back  through  the  right 
distal  corner,  down  through  the  left  distal  corner,  and  back  through  the 
left  proximal  corner.  This  leaves  two  loops,  as  shown  in  Fig.  516. 
These  are  passed  between  the  teeth  mesially  and  distally  of  the  selected 
tooth ;  the  free  ends  are  pulled,  drawing  the  lingual  loop  up  to  the  tooth. 
The  free  ends  are  now  made  into  a  surgeon's  knot.     This  is  to  be  left 


DENTO-ALVKOLAli  AJJSCE.SS  441 

until  the  tenderness  of  tlie  Jil)S('<\sse(I  tooth  li;is  almost  ^'onc.  Aco/iit(; 
and  iodin,  equal  parts  of  the  tincture,  or  dental  tincture;  of  aconite, 
should  be  painted  upon  the  gums,  a  ])ad  of  cottonoid  })hiced  over  it, 
and  the  patient  cautioned  not  to  swallow  the  sahva. 

Cold  antiphlogistics,  such  as  lead  water  and  laudanum  or  cataplasma 
kaoHni,  should  be  ap])lied  externally.  No  hot  external  applications 
should  be  used  in  abscess  cases,  as  they  may  cause  an  external  fistula 
to  be  formed. 

The  mouth  is  to  be  frequently  washed  with  an  antiseptic.  In  simple 
cases  with  prompt  relief  this  is  all  that  is  necessary;  in  marked  cases  the 
reduction  of  the  inflammatory  engorgement  should  be  attempted  in 
addition. 

Fig.  516 


Rubber  dam  guard  for  use  in  pericementiti.s:   A,  roll  of  dam  threaded;  B,  guard  fitted  over  tooth; 
tooth  eliminated  to  show  the  manner  in  which  the  silk  encircles  it. 

Sweedish  leeches  may  be  applied  to  the  gum,  or  a  cut  or  two  made 
in  the  gum  over  the  apex  of  the  tooth  will  allow  free  bloodletting  and 
drainage  of  the  excess  of  blood  in  the  pericementum,  A  hot  pedi- 
luvium  and  a  saline  cathartic  conjoined  are  useful  as  counterirritant 
derivatives,  and  the  latter  is  also  depletive,  reducing  the  volume  of 
the  blood.  The  hot  pediluvium  with  mustard  added  and  diaphoresis 
conjoined  are  also  useful.  Ten  grains  of  Dover's  powder  in  divided 
doses  in  hot  lemonade  are  given,  in  part,  while  the  pediluvium  is  being 
administered,  and  the  patient  is  later  well  covered  up  in  bed. 

Quinine  in  doses  of  gr.  vj  is  given  as  a  febrifuge  and  to  limit  exuda- 
tion, and  tincture  of  aconite,  two  drops  at  first  and  one-half  drop 
each  half  hour,  is  given  until  the  volume,  tension,  and  frequency  of  the 
pulse  are  reduced. 

If  syphilis  be  a  complication  in  these  cases,  potassium  iodid,  in 
doses  of  10  grains  each  three  hours,  is  useful  as  an  antagonist  of  its 
influence  and  as  a  nervous  sedative.  Unless  Dover's  powder  is  used, 
morphin  sulfate  in  blondes  and  morphin  bimeconate  in  brunettes, 
especially  those  with  blue  eyes,  or  any  persons  with  known  idio- 
s>mcrasies  to  morphin,  should  be  administered  in  s  grain  doses  repeated 
each  hour  up  to  |  grains.  When  great  suffering  renders  it  necessary, 
a  hypodermic  may  take  its  place.  When  used,  a  saline  cathartic  should 
be  given  the  following  morning. 

The  Second  Stage  of  Acute  Apical  Abscess. — In  this  stage  the  pus  is  in 
the  bone  and  the  infection  considered  more  \  irulent,  ?'.  e.,  the  germs  are 


442  TREATMEXT  AX  J)  F/LLIXa  OF  HOOT  CAXALS 

espt'oially  {ictivc  Tlie  ahortive  treatment  should  first  be  tried,  and  if 
free  venting  of  pus  is  obtained,  relief  is  usually  given.  If  not  given  the 
case  continues  to  the  third  stage.  If  bearable,  or  the  surgieal  method 
be  impraetieable,  a  dcMital  capsicum  plaster  may  be  applied  to  the  gum 
or  a  roasted  half-raisin  may  be  applied.  Either  causes  an  inflannnation 
of  the  gum,  which  advances  the  tissue  that  much  nearer  suppuration. 
Thus,  it  prepares  a  readily  invaded  tissue  and  hastens  pointing. 
The  contrary  efl'ect  has  sometimes  been  produced,  and  is  explained 
upon  the  ground  that  the  increased  amount  of  blood  has  increased  the 
pliagocytosis  and  destruction  of  bacteria  or  has  stimulated  a  restoration 
of  the  circulation,  possibly  both.  Morphin  is  a  useful  adjunct  when 
the  pain  is  severe.  For  the  purpose  of  hastening  suppuration,  calx 
suli)hurata,  i  grain  each  hour,  is  useful.  It  also  sometimes  hastens 
resolution.     It  is  proper  to  denominate  this  the  expectant  treatment. 

When  tolerable  or  imperative,  the  surgical  method  of  venting  the 
abscess  through  an  oi)ening  in  the  gum  is  valuable.  The  apical  region 
is  located  as  nearly  as  possible  by  measuring  the  length  of  the  tooth  with 
a  probe  passed  into  the  canal  and  over  which  a  small  piece  of  rubber  dam 
is  slipped  as  a  guide.  This  is  laid  over  the  crown  and  gum  and  a  tiny  drop 
of  carbolic  acid  is  placed  just  above  the  point  of  the  pro})e.  A  vertical 
cut  is  made  in  the  gum  down  to  the  bone  and  a  broad  spear  drill 
is  driven  through  it  into  the  abscess  tract.  Whether  this  shall  be 
done  under  ethyl  chlorid  refrigeration,  cocainization,  or  short  general 
anesthesia,  the  operator  must  determine. 

A  gradual  perforation  is  usefid  in  some  cases.  This  method,  designed 
by  Black,  consists  in  gradually  escharing  and  scratching  the  gum  tissue. 
Successive  applications  of  just  such  carbolic  acid  as  adheres  to  the  point 
only  of  a  sharply  serrated  plugger  are  made,  followed  by  slight  scratch- 
ing only  so  that  blood  shall  not  be  drawn.  In  this  way  the  bone  is 
ultimately  reached. 

Afresh  drop  of  acid  is  applied,  the  periosteum  scraped  away  slightly, 
and  the  drill  then  used. 

A  Rollins  tubular  knife  (Fig.  517)  has  been  used  with  success  to  remove 
a  piece  of  gum,  after  which  the  drill  or  a  fine  trephine  (Fig.  518)  is  used. 
Some  acute  pain  may  follow  this  operation,  but  usually  lasts  only  a 
short  time. 

If  antiseptics  are  used  to  syringe  out  the  abscess  cavity,  it  is  better 
to  use  a  mixture  of  six  parts  hammamelis  (aqueous)  and  one  part 
Listerin  as  a  partial  sedative.  The  use  of  hydrogen  dioxid  is  often 
very  painful,  owing  to  the  rapid  reaction  with  the  blood  present;  and  as 
it  sometimes  also  drives  the  infective  material  into  remote  parts  without 
disinfecting  it,  its  use  in  this  connection  is  not  without  danger,  and 
should  be  avoided. 

If  extraction  be  imperative  during  the  second  stage  of  pus  formation, 
it  may  be  performed  and  removes  the  exciting  cause.     The  aheolar 


DENTO-A  L  VEOLA  H  A  liSCESS 


443 


apex  sliouid  1)C  sterilized,  aiul  if  return  of  sej)sis  is  feared,  a  tent  of 
antiseptic  gauze  may  be  inserted  for  a  day  only,  and  should  then  l)e 
re'm()\(>(l  and  the  cavity  resterilized.  Then  a  clot  is  invited  by  curetting 
the  part.     Ordinarily  the  extraction  and  free  bleeding  cures  the  case. 

If  secondary  swelling  occur,  it  is  easy  to  remove  the  clot  and  then 
treat  as  above.  The  consensus  of  opinion  of  the  best  informed  of  the 
profession  is  that  this  procedure  is  correct. 

The  Third  Stage  of  Acute  Apical  Abscess. — In  this  stage  the  pus  has 
found  its  \\ay  through  or  beneath  the  periosteum  on  the  outside  of  the 
bone;  therefore,  its  germs  are  engaged  in  liquefying  the  gum  tissue  or  in 
unusual  location  the  mucosa  or  muscular  tissue  of  the  part.  Except  in 
these  cases  the  gum  is  tumefied,  a  hard,  circumscribed,  inflamed  nodule 
indicating  pus  near  the  bone,  a  soft,  more  generally  diffused  swelling 
indicating  more  superficially  located  pus,  while  a  soft  yellow  or  yellowish- 


FiG.  517 


Fig.  518 


o  O 


Fig.  519 


Tubular  knives. 


Walker-Younger  trephines.  Rubber  cap  used  as  a  vacuum  cup. 


pink  tumefaction  indicates  pointing.  In  all  these  cases  the  indication 
is  for  a  surgical  opening  of  the  gum  rather  than  the  opening  of  the  tooth. 
The  part  should  be  gently  disinfected  with  hydrogen  dioxid  on  a  ball 
of  cotton,  and  a  sharp  bistoury  should  be  boldly  driven  to  the  bone,  with 
the  cutting  edge  turned  toward  the  occlusal.  The  lip  or  cheek  is  to  be 
drawn  well  away  to  avoid  injuring  the  coronoid,  buccal,  or  facial  artery. 
A  cut  about  three-quarters  of  an  inch  in  length  is  rapidly  made  by 
sweeping  the  edge  and  point  downward  occlusally.  Too  deep  lancing 
upon  the  hard  palate  may  injure  the  posterior  palatine  artery. 

As  this  is  usually  painful,  it  is  better  to  refrigerate  the  gum  or  operate 
under  short  general  anesthesia,  e.  g.,  nitrous  oxid  or  the  first  impres- 
sion of  ether.  Cocain  is  only  useful  in  the  case  of  deep-seated  pus. 
Next,  the  abscess  tract  is  to  be  gently  washed  out  with  a  diluted  ham- 
mamelis  solution,  preferably  warmed.  This  may  be  done  with  the 
abscess  s\Tinge  (Fig.  521). 


444 


r  RE  ATM  EXT  A.\D  FILLIXG  OF  ROOT  CANALS 


If  tlic  abscess  has  hcfri  (Iccp-scatcfl  ir  is  well  to  introduce  a  fine  tent 
of  antiseptic  gauze  throuj,Hi  the  opening  into  the  abscess  tract  to  pre- 
vent the  too  rapid  healing  of  the  external  orifice  which  is  apt  to  occur, 
owing  to  the  approximation  of  tlie  hps  of  the  wound  pro(hiced  by  cheek 
pressure.     This  Jieahng  permits  a  second  coUection  of  pus.    The  tent 


Fio.  521 


Minim  pjTinge. 


J.  X.  Farrar's  alveolar-absress  syringe. 


should  be  removed  not  later  than  the  next  da>',  the  abscess  tract  disin- 
fected again,  possibly  with  a  mercuric  chlorid  solution,  and  the  tent 
replaced.  At  this  time  the  tooth  should  be  opened  and  disinfected  if 
not  tolerable  at  the  first  sitting.  When  this  is  tolerable  the  crown 
should  be  tapped  and  formocresol  sealed  in  the  pulp  chamber  just  before 
the  operation  of  lancing,  in  order  to  permit  disinfection,  and  thus  limit 


DEN  TO  A  1. 1  'KOLA  It  A  JiS(  'ESS  4-45 

pus  formation  and  to  saA'c  time.  Tents  in  alveoli  should  never  be  left 
a  long  time,  as  they  beeome  septic  and  may  cause  necrotic  conditions 
of  the  alveolus. 

The  patient  should  always  be  cautioned  to  remove  the  tent  if  swelling 
return,  as  this  indicates  a  stoppage  of  the  vent  with  collection  of  pus. 

When  diffuse  cellulitis  with  marked  febrile  disturbance  passing  into 
the  adynamic  type  is  produced,  one  should  fear  the  infection  with 
Streptococcus  pyogenes  and  treat  not  only  locally,  but  use  blood  germi- 
cides against  a  possible  septicemia.  In  these  cases  there  is  little  pus 
formed  compared  with  the  area  involved. 

The  following  is  especially  useful  as  a  systemic  antiseptic  stimulant: 

I^ — Hydrargyri  bichloridi gr.  j 

Tinctune  fcrri  chloridi f5j — M. 

Sig. — Twenty  drops  in  water  four  times  a  day. 

If  the  adynamia  and  other  symptoms  be  progressive,  medical  cooperation 

should  be  obtained  to  divide  the  responsibility  and  to  afford  every 

means  possible  toward  the  cure.    The  extraction  of  the  tooth  followed 

by  sterilization  and  curettement  of  the  part,  and  the  use  of  streptococcus 

antitoxin  conjoined  with  the  sustention  of  the  vital  powers  by  nutritious 

predigested  food  and  alcohol  is  logical.    In  even  ordinarily  severe  cases 

not  of  this  variety  there  will  be  some  fever  due  to  the  toxin  absorbed, 

and  the  pain,  and  loss  of  sleep  and  appetite  will  cause  physical  debility. 

For  this  there  is  nothing  better  than  the  following,  as  tonic,  antiseptic, 

and  antipyretic: 

I^— Saloli, 

Quininse  sulphatis  (vel  hydrochloratis)  .      .      .  .  .   aa     gr.  Ix 

M.  et  fiant  capsulse  no.  xx. 
Sig. — Take  one  four  to  six  times  daily,  before  meals  when  near  them. 

I^ — Quinina)  sulphatis gr.  xxx 

Acetanilidi gr.  xxiv 

Caffeinifie  citratis gr.  iij 

M.  et  fiant  pil.  no.  xij. 

Sig. — One  every  hour.    (Endelmann.) 

The  facial  swelHng  resolves  with  the  cure  of  the  abscess  or  its  proper 
venting,  but  may  be  assisted  by  cold  applications  or  cataplasma  kaolini 
to  the  outside  of  the  face  and  by  gentle  massage  by  the  patient  or 
nurse.  Indurated  swelling  may  be  assisted  in  reduction  by  the  operator 
through  vibratory  massage. 

A  piece  of  metal  drilled  through  one  end  and  mounted  on  a  No.  303 
mandrel  may  be  revolved  while  the  engine  handpiece  is  strapped  to  or 
held  in  the  hand.^  This  imparts  a  vibratory  motion  to  the  hand  useful 
when  the  lubricated  finger-tips  are  pressed  over  the  face  or  gums. 

The  heat  of  a  large  electric  lamp  concentrated  upon  the  face  from  a 
short  distance,  and  followed  by  massage,  is  also  useful  in  facial  swellings 
due  to  cellulitis. 

1  W.  H.  Mitchell,  Dental  Brief,  1908,  Academy  of  Stomatology. 


44()  TREATMENT  AND  FILLING  OF  ROOT  CANALS 

After  the  reduction  of  acute  inflammatory  s>  mptoms  tlie  treatment  is 
the  same  as  in  tlie  forms  of  moist  jjangrene  (which  see).  The  canals  arc 
stcriHzed  by  formocrcsol  for  a  time,  then  o])cncd,  dressed  with  anti- 
septics, and  when  the  abscess  is  cured  the  canal  is  to  be  filled. 

Treatment  of  Chronic  Apical  Abscess. — As  stated  in  the  pathology, 
chronic  ai)ical  abscess  appears  in  three  forms: 

1 .  With  point  of  discharge  through  the  root  canal. 

2.  With  point  of  discharge  through  a  sinus  or  fistula  in  the  bone  and 
gum  or  other  soft  tissue. 

3.  Without  point  of  discharge  as  a  latent  focus  of  pus  formation 
within  the  bone  or  apical  tissue  (an  encystment  of  the  pus)  (Fig.  515). 

1.  In  the  first  form  the  abscess  sac  consists  of  the  apical  tissue  which 
has  undergone  more  or  less  organization  into  fibrous  tissue  surrounding 
the  ca\ity  of  the  abscess,  the  lining  of  which  continually  undergoes 
solution  into  pus,  which  escapes  via  the  open  canal  (Fig.  522). 

This  is  usually  the  sequence  of  the  abortive  treatment  of  acute 
apical  abscess  or  of  an  open  canal  produced  by  caries. 

In  the  first  variety  the  abscess  cavity  is  usually  of  a  size  dependent 
upon  the  size  of  the  acute  abscess  cavity  and  gradually  grows  smaller  as 
the  tissue  organizes.     In  the  second  the  abscess 
Fiu-  522  cavity  may  grow  gradually  larger  as  food  packs 

into  the  cavity  of  decay  and  produces  stoppage 
or  semistoppage  of  the  canal  vent  (Figs.  505, 
506,  and  50(S).  According  to  the  condition  found 
by  instrumentation  or  a'-rays,  or  inferred  by  sub- 
sequent symptoms,  the  grades  to  be  treated  may 
be  classed  as: 

(a)  Those  in  which  acute  abscess  aborted  has 
resulted  in  pus  cavity  closure  to  a  point  of  al- 

C'hronic     apical      abscess,  .  ^. 

third  grade:     iJ.  abscess  sac        mOst  obliteration. 

containing  a  central  pus  cav-  /^)  Thosc  iu  which  a  Small  sac  Containing  a 

it  v;  D,  apex  of  root;  C,  canal        »    .     i  •      »  i 

containing  pus.  fair  lumcn  IS  round. 

(c)  Those  in  which  a  large  fibrous  sac  exists 
and  which  is  sometimes  from  one-fourth  to  three-fourths  of  an  inch  in 
length,  with  a  corresponding  lumen  (Fig.  522). 

(f/)  Those  in  which  the  pus  sac  and  bone  is  liquefied  and  the  bone  is 
more  or  less  necrotic  (Fig.  508). 

Gentle  probing  will  usually  give  a  guide  to  the  extent  of  the  abscess. 
The  treatment  for  the  first  three  gi-ades  consists  of  obtaining  free  access 
to  and  drainage  of  the  abscess  tract.  This  should  be  done  with  formalin, 
5  per  cent,  aqueous  to  full  strength  formocresol,  in  the  canal  to  sterilize 
what  infectiNe  material  exists,  and  pre\ent  extraneous  infection.  The 
sealing  in  of  formocresol  should  now  be  done  as  in  moist  gangrene. 

If  the  infective  material  be  not  killed  out  there  will  be  pus  found 
in  the  canal.    This  should  be  reino\^ed  after  twenty-four  or  forty-eight 


DENTO'ALVEOLAR  ABSCESS  447 

hours,  and  a  new  dressing  applied.  If  after  the  first  application  no  j)us 
be  found  and  no  acute  abscess  be  lighted  up,  the  cotton  dressing  is 
more  tightly  introduced  after  appropriate  canal  enlargement  if  more 
be  needed. 

Each  dressing  should  be  examined  for  pus  and  a  dry  cotton  introduced 
to  take  up  any  if  a  flow  of  it  follow  the  remo\'aI  of  the  dressing.  Hydro- 
gen dioxid  should  not  be  forced  into  such  an  abscess,  as  great  pain  may 
result  from  the  reaction  with  the  pus  and  blood. 

When  a  tight  cotton  dressing  has  been  in  place  a  week  and  the  canal 
dressing  exhibits  no  odor  of  putrescence  nor  flow  of  pus,  the  root  canal 
may  be  filled  at  least  at  the  apex.  In  the  third  grade  (c)  an  acute 
abscess  is  liable  to  be  set  up,  although  under  formalin  influence  it  may 
heal. 

In  a  relatively  few  cases  teeth  cannot  be  closed  at  all  without  a 
recurrence  of  trouble  within  a  short  period,  which  trouble  is  usually 
relieved  by  opening  the  tooth.  The  repetition  of  this  is  annoying,  and 
in  some  cases  is  due  to  the  strength  of  medicaments,  such  as  formalde- 
hyd,  which  should  be  modified  or  abandoned  for  sedati^'e  antiseptics, 
such  as  phenol-camphor  or  eugenol  plus  menthol.  In  some  of  the  cases 
the  gases  may  accumulate  more  rapidly  than  disinfection  occurs.  In 
other  cases  the  irritability  of  the  tissues  seems  to  produce  intolerance 
of  any  remedial  measures.  What  is  known  as  "  systematic  stopping  and 
unstopping"  seems  sometimes  to  overcome  the  irritability  and  accustom 
the  tissues  to  being  covered.  The  system  consists  of  stopping  with  eugenol 
and  menthol  or  modified  formocresol  for  about  eight  hours,  or  from 
morning  to  afternoon,  then  venting  and  redressing  until  the  following 
morning,  then  for  twenty-four  hours,  then  forty-eight,  then  seventy- 
two,  etc.,  until  the  tooth  stays  stopped. 

There  have  been  a  few  patients  who  cannot  seem  to  ha^'e  teeth 
"treated,"  nearly  all  cases  being  practical  failures  even  when  aseptic. 
Some  few  may  be  kept  in  comfort  for  a  while  with  permanent  vents, 
but  this  is  objectionable.  The  making  of  an  artificial  fistula  should  be 
attempted.  In  some  cases  the  writer  has  found  an  error  of  diagnosis 
on  his  part  in  that  apparent  apical  irritability  has  been  due  to  a  fine 
filament  of  ulcerated  pulp  in  the  extreme  apical  end  of  the  canal.  This 
having  been  punctured  full  of  carbolic  acid  and  removed,  the  case  has 
proceeded  to  a  cure. 

The  fourth  grade  {d)  is  almost  certain  to  cause  reaction.  In  either 
ease  an  external  opening  should  then  be  made,  establishing  a  fistula. 
If  these  grades  can  be  diagnosticated  beforehand,  it  is  well  to  do  this 
before  canal  treatment. 

2.  Cases  which  have  an  established  fistula  are  usually  easy  of  treat- 
ment mechanically. 

In  all  cases  the  organized  tissue  lining  the  abscess  tract  is  breaking 
down  into  pus  and  continually  regenerating  itself  except  in  a  fair  number 


448  Th'hWTMI'JXT  AM)  FILLISd  OF  HOOT  CANALS 

of  cases  in  wliich  tlie  abscess  cavity  enlarges  at  the  expense  of  the  organ- 
izing tissne.  This  latter  result  is  usually  due  to  gravity,  which  confines 
the  ])us  germs  in  crypts  of  the  abscess  walls. 

The  canals  should  be  made  continuous  with  tlie  abscess  cavity.  This 
is  not  always  easy  in  molars,  and,  as  a  rule,  canals  which  have  sensitive 
tissues  at  their  ends  should  not  have  this  tissue  lacerated. 

Instead,  in  molars,  after  due  and  moderate  cleansing  of  canals  an 
api)lication  of  formocresol  for  twenty-four  hours  before  thorough 
canal  manipulation  is  wise.  They  are  then  freely  opened  and  formo- 
cresol dressings  placed  in  them.  If  the  fistula  does  not  show  signs  of 
healing  in  a  week  it  should  be  washed  out  with  antiseptics  and  the 
canal  which  did  not  have  sensitivity  at  its  end  should  be  filled  with 
a  thread  of  cotton  saturated  with  carbolic  acid  or  phenolsulphonic  acid,^ 
and  pressure  made  upon  it  with  raw  vulcanite  to  force  it  through  the 
foramen  and  into  the  abscess  tract.  A  bit  of  cottonoid  should  be 
])laced  owv  the  fistula  to  pre\'ent  the  escharing  of  the  mucosa.  The  pus- 
forming  area  is  thus  eschared,  killing  the  invading  bacteria  and  stimu- 
lating the  tissue  to  regeneration. 

The  canal  is  again  dressed  with  formocresol  and  a  week  or  more 
allow^ed. 

Hydrogen  dioxid  should  be  avoided  in  this  connection,  as  it  has 
forced  the  infective  material  into  distant  parts  of  the  abscess  tract 
without  disinfecting  it. 

The  medicament  may  be  drawn  rather  than  forced  through  by  the 
use  of  an  unperforated  rubber  cup  pressed  upon  the  wet  gum  and  then 
released.  It  acts  as  a  vacuum  cup  (Fig.  522,  a).  This  rubber  cup  may 
be  mounted  upon  a  tube  having  a  shoulder  filed  on  it  and  the  tube  be 
attached  to  the  saliva  ejector  or  a  rubber  bulb. 

If  pus  formation  persist,  and  especially  if  the  pus  be  found  on  the 
end  of  the  dressing,  or  the  foramen  be  widely  open,  the  pus  either 
flows  into  the  canal  and  becomes  a  continuous  cause  of  infection; 
or  the  cotton  goes  through  the  root  end  and  acts  as  an  irritant.  In 
either  case  the  filling  of  the  canal  is  indicated.  This  forces  all 
jnis  to  remain  external  to  the  canal.  The  fistula  should  now  be  irri- 
gated with  sulphuric  acid,  25  per  cent.,  to  dissolve  any  calculi  present, 
kill  bacteria  in  the  abscess  crypts  or  cemental  lacunse,  and  stimulate 
the  tissue  (Fig.  50s).  Care  is  to  be  nscd  not  to  eschar  the  oral  tissues 
or  afi'ect  the  clothing  of  the  patient.  A  minim  syringe  limits  the  amount 
used  and  a  pad  of  cottonoid  catches  any  excess  if  this  be  not  used  (Fig. 
520).  If  this  fail  after  weekly  attention  for  a  month  or  more,  there  is 
probably  dead  bone  or  a  dead  and  infected  root  end,  and  root  amputa- 

'  Aciil  ph('ii(tlsul])lK)iiic  consists  of  !I7  i)arts,  In-  wcif^ht,  of  concoiit rated  sulfuric 
acid  and  93  i)arts,  by  wcifiht,  of  ])lu'iiol,  kept  at  1()0°  C.  for  about  twenty-four  liours 
to  produce  a  reaction,  wlien  sufficient  distilled  water  is  added  to  make  the  liquid  assay 
about  <S()  jjcr  cent,  of  phenolsulphonic  acid.    (I>uckley  Lilly.) 


J)I'JNT()  ALVEOLAR  ABHCESH  449 

tioii  is  in  ordor.  There  is  an  exception  to  this  rule  in  some  cases,  Tiie 
writer  has  had  these  fistuhne  heal  up  when  let  alone  for  a  time,  and  if 
no  signs  of  active  pus  formation  are  present  this  may  be  resorted  to. 

In  other  cases  the  gravity  of  the  pus  alone  has  prevented  healing, 
and  when  the  patient  has  been  instructed  in  the  use  of  a  Sub.  Q  syringe 
and  antiseptic  solution  several  times  a  day,  the  abscess  has  healed.  The 
theory  is  that  the  constant  remo\'al  of  the  pus  has  given  the  granulations 
opportunity  to  spring  up. 

The  use  of  the  rubber  cup  (Fig.  519)  as  a  vacuum  cup  draws  ])us 
from  apical  abscesses  and  stimulates  a  flow  of  fresh  blood  in  the  area. 
This  blood  is  said  to  have  a  higher  op- 
sonic index  than  normal  blood,  and  hence  F'*^-  ^-■^ 
greater    phagocytic    effect.      It    acts    to 
massage  the  gum  and  may  be  applied  by 
the  patient.      A  small  glass  cup  or  rubber 
cup  with  rubber  bulb  attached  may  be 
used  for  the  purpose.     (See  previous  de- 
scription.) 

The  amputation  of  root  apices,  while 
not  always  productive  of  the  desired  heal- 
ing, at  least  benefits  the  case.  A„>putation  of  root  apex:    og, 

A  radiograph    is    a    useful    guide   to    the        opening  in  the  gum  made  by  packing 
.    .  c  j_  •  1  •    11  i»        fistula;  AC,  absces3  cavity;  RF,  root 

position  or  root  apices,  and  especially  or     fining. 

the  root  causing  the  abscess  if  not  known 

(Fig.  515).    When  located,  the  fistula  should  be  lanced  open  and  the 

orifice  in  the  bone  enlarged,  if  necessary. 

The  abscess  cavity  is  then  packed  with  gauze  until  the  root  apex  is 
visible;  it  is  then  removed  by  means  of  a  dentate  fissure  bur  laid  against 
its  side.  The  canal  must  previously  have  been  solidly  filled  with  gutta- 
percha or  oxychlorid  of  zinc.  The  root  should  be  trimmed  down  with 
burs  to  a  point  below  the  healthy  bone  level.  All  necrotic  bone  is  to  be 
removed  (Fig.  523). 

A  variant  of  this  operation  was  introduced  by  INI.  Schamberg.  It 
consists,  after  root  location  by  instrumentation  or  radiograph,  of 
entering  the  diseased  area  with  a  surgical  bur  and  cutting  away  the 
root.     This  is  the  simpler  technicjue,  if  one  be  sure  of  his  position. 

For  a  short  time  this  cavity  may  be  packed  with  gauze,  or  a  clot  may 
be  invited,  the  mouth  and  parts  kept  sterile,  and  the  case  watched.  If 
necessary,  stimulation  of  the  tissue  by  silver  nitrate  or  scarification 
should  be  employed. 

The  part  heals  by  granulation  and  new  bone  is  generated. 

When  the  fistula  is  upon  a  perforation  near  the  root  apex,  or  a  much 

lacerated   foramen,  the  canal  may  be  filled  with  oxychlorid  of   zinc. 

which  is  allowed  to  go  through  the  opening  into  the  fistula.    The  excese 

of  this  is  removed  after  partial  hardening  of  the  material.     In  fistulae 

29 


450 


THE  AT  ME  ST  AM)  FILLING  OF  ROOT  CANALS 


locati'd  U|)()ii  low  hiteral  perforations,  either  oxychlorid  of  /Iik;  or 
oxypliosphate  of  copper  are  worked  through  and  allowed  to  set.  The 
excess  in  the  fistula  is  then  removed. 

If  in  any  ease  this  does  not  heal,  the  fistula  is  to  be  packed  open 
with  <j:auze  and  a  retention  cavity  made  in  the  root  side  if  accessible. 
This  is  filled  with  a  tight  amalgam,  compressed  air  being  used  to 
keep  the  part  dry.  If  impossible  to  keep  dry,  the  cavity  is  touched 
with  silver  nitrate  and  the  filling  well  compressed  under  a  stream  of 
water. 

Time  for  healing  may  be  required  in  some  of  these  cases.  If  these 
latter  cases  Avill  not  heal,  or  the  filling  methods  are  not  successful  or 
I)()ssible,  extraction  and  replantation  is  the  last  resort,  if  the  tooth  be 
valuable. 


Fig.  524 


Fig.  525 


A  skiagraph  of  apical  ab- 
scess cavity  about  two  root 
apices;  incurable  by  ordi- 
nary means. 


The  same  after  root 
amputation. 


The  same  thirty  da.vs 
later,  showm?  a  certain 
amount  of  new  bone  for- 
mation.    (Price.) 


An  impression  is  taken  with  the  tooth  in  place,  and  a  splint  is  con- 
structed over  the  model,  the  occlusion  being  considered.  The  tooth  is 
extracted,  the  abscess  tract  curetted,  and  the  aheolus  packed  with 
antiseptic  gauze  or  cotton  tampon  saturated  with  50  per  cent,  phenol- 
sodique. 

The  tooth  apex  is  slightly  cut  off,  the  canal  opened  from  the  apex, 
and  the  tooth  dropped  into  a  germicidal  solution,  as  lysol,  5  per  cent., 
or  50  per  cent,  phenol-sodique. 

After  a  time  it  is  dried,  the  canal  filled  with  gutta-percha,  the  ])er- 
foration  filled,  and  the  tooth  returned  to  the  solution. 

The  tampon  is  remo\'ed,  the  socket  again  syringed  out,  when  the 
tooth  is  returned  to  place,  the  part  dried,  and  the  retaining  device 
cemented  in  place.  This  should  remain  in  place  for  about  eight  weeks, 
to  allow  reunion  or  ankylosis  to  occur. 

If  the  parts  be  badly  infected,  it  may  })e  well  to  allow  a  few  days  to 
elaj)se  between  the  extraction  and  the  replantation.  In  the  interim 
the  tooth  may  be  prepared.     If  the  tooth  is  to  be  replanted  in  a  new 


DENTO- ALVEOLA  It  ABSCESS  451 

position  the  tootli  must  be  cut  from  the  ])hister  model,  a  hole  drilled 
ill  the  base  of  the  model  and  the  tooth  put  in  its  proper  relation.  The 
splint  is  then  constructed.  At  the  time  of  replantation  the  socket  may 
l)e  freed  of  clot  and  any  granulation  by  the  use  of  a  bone  reamer  gently 
applied.  In  some  cases  the  transplantation  of  another  tooth  or  root 
with  an  artificial  crown  upon  it  may  be  done  instead  of  replanting  the 
tooth.     (See  chapter  on  Plantation.) 

Fistulse  upon  the  Face. — If  a  fistula  be  formed  upon  the  face  it  will 
usually  heal  if  the  root  canal  can  be  made  continuous  with  the  abscess 
tract  and  no  necrotic  bone  be  present  other  than  that  usually  formed 
by  a  chronic  abscess.  This  done,  the  treatment  is  the  same  by  means 
of  formocresol  sealed  in.  If  pus  ceases  to  form,  the  apex  of  the  reamed 
canal  may  be  filled  wdth  gutta-percha  made  antiseptic  with  aristol  or 
iodoform,  formocresol  placed  in  the  remaining  open  canal,  the  tap 
sealed,  and  time  allowed  for  healing.  If  it  will  not  heal,  amputation 
and  bone  curettement  may  be  done  from  within  the  mouth.  Still  failing, 
extraction  is  the  final  resort.  These  fistulse  heal  with  least  scar  if  the 
tooth  be  not  extracted  (Fig.  509) . 

If  cicatricial  tissue  form  within  the  cheek  tissue  it  may  bind  the 
cheek  tissues  to  the  bone  in  such  a  way  as  to  cause  a  depression  of  the 
facial  scar.  To  remedy  this  a  cut  should  be  made  in  the  tough  fibrous 
cicatricial  cord  from  within  the  mouth,  while  the  cheek  is  drawn  outward. 
A  pin  is  to  be  passed  through  the  depressed  portion  of  the  facial  cicatrix 
and  a  small  compress  of  gauze  laid  under  each  end  (Black).  This 
raises  the  centre  of  the  cicatrix,  separates  the  cut  ends  of  the  cord, 
and  permits  a  new  growth  of  tissue  to  reunite  it  into  a  cord  of  greater 
length,  which  causes  less  binding  (Fig.  510). 

Fistula  in  the  Antrum  of  Highmore. — In  recent  cases  this  may  consist 
of  a  simple  fistula  discharging  pus  into  the  antrum.  The  diagnosis  can 
only  be  made  inferentially  when  an  acute  abscess  in  the  region  has 
suddenly  subsided,  and  actually  by  pressing  a  fine  probe  or  forcing  a 
stream  of  antiseptic  fluid  through  the  root  canal  into  the  antrum,  or 
by  skiagraphy.  If  treated  like  any  other  fistula  by  way  of  the  canal, 
it  should  heal,  and  some  cases  seem  to  have  done  so.  In  long-con- 
tinued cases,  with  general  septic  inflammation  of  the  antral  mucosa 
and  offensive  discharge  into  the  nasal  cavity,  the  antrum  must  be 
opened.  The  mucous  membrane  of  the  patient  is  anesthetized  and 
an  opening  made  through  the  lower  buccal  wall  of  the  antrum  large 
enough  to  permit  of  satisfactory  examination.  After  sterilization  of 
the  antral  cavity,  all  necrotic  bone  should  be  removed,  and  the 
antral  cavity  irrigated  with  antiseptics  and  packed  for  a  period  with 
a  long  strip  of  antiseptic  gauze  fed  directly  from  a  wide  mouthed 
bottle  in  which  it  has  been  kept.  Later  it  may  be  irrigated  for  stimu- 
lation, with  Lugol's  solution  (liquor  iodi  compositus,  gtt.  xx  to  the 
ounce),  or  upon  occasion  even  with  pure  tincture  of  iodin  or  an  alcohohc 


452  TliEATMENT  AND  FllJJSd  OF  ROOT  CANALS 

dilution  of  it.  The  root  canals  should  preferably  have  been  ])revi()usly 
sterilized  and  filled.  If  necessary  the  root  apex  affected  may  })e  ain]ju- 
tated  at  the  time  of  operation.  After  healinj^  of  the  antrum,  if  the 
opening  does  not  heal,  a  slight  plastic  operation  upon  the  mucous 
membrane  will  usually  close  it  (Fig.  50-4). 

In  all  irrigations  of  the  antrum  the  head  should  be  inclined  forward 
over  a  basin  to  allow  the  solution  to  run  out  of  the  nasal  cavity.  In 
using  iodin  it  is  well  to  pack  the  nostril  on  the  affected  side  with  cotton, 
removing  it  after  the  irrigation. 

In  cases  in  which  the  pus  finds  its  way  along  the  root  of  the  tooth 
and  discharges  at  the  gum  margin,  there  is  liable  to  be  more  or  less 
calculus  deposited  upon  the  root  surface,  causing  it  to  simulate  a  case 
of  pyorrhea  alveolaris.  The  calculus  may  exist  also  at  the  apex  in  some 
old  cases  of  chronic  apical  abscess  with  the  ordinary  form  of  fistula. 
This  calculus  should  be  removed  with  pyorrhea  instruments  or  by 
injection  of  10  to  25  per  cent,  sulfuric  acid.  Otherwise  the  cases  do 
not  differ  from  the  ordinary. 

Systemic  Complications. — The  cachectic,  debilitated,  anemic,  tubercu- 
lous, and  syphilitic  are  liable  to  extensive  pus  formation,  which  enlarges 
the  ca\"ity  unduly  and  may  invohe  the  roots  of  other  teeth  or  e^■en 
cause  de\'italization  of  their  pulps,  which  aids  in  the  continuance  of  the 
abscess  by  adding  a  fresh  cause. 

In  such  cases  all  the  dead  pulps  should  be  removed  after  careful 
diagnosis,  and  the  patient  should  be  instructed  in  the  use  of  a  Sub.  Q 
syringe  and  a  mild  antiseptic,  the  object  being  to  keep  the  dependent 
parts  free  of  pus  and  allow  granulations  to  form  rather  than  be  con- 
stantly broken  down. 

In  addition,  such  systemic  medication  or  remedial  measures  as  will 
raise  the  recuperative  and  resistant  powers  of  the  tissues  should  be 
employed. 

If  very  persistent,  a  vaccine  may  be  employed,  after  the  method 
of  Wright,  to  raise  the  opsonic  index.  (See  chapter  on  Pyorrhea 
Alveolaris.) 

The  direct  results  of  infection  toxemic  and  septicemic,  ha\  e  already 
been  considered  (see  p.  445). 

3.  In  the  third  class  of  cases  the  diagnosis  is  either  made  because 
of  a  latent  swelling  on  a  filled  tooth  or  cyst  of  fluid  contents  overlying 
a  root  apex,  or  because  of  subacute  apical  irritation,  which  either 
opening  the  tooth  demonstrates  to  be  due  to  septic  causes,  or  a  radio- 
graph shows  to  be  an  abscess  cavity.  The  presence  of  eruptions  upon 
the  body  not  otherwise  accounted  for  or  other  evidence  of  toxemia 
should  cause  these  latent  abscesses  to  be  sought  as  the  source  of  toxic 
effects.  In  the  case  of  a  cyst  a  fistula  should  be  established;  in  the 
other  the  canals  should  be  opened  and  the  tooth  treated  as  for  the 
first  or  second  grade  of  abscess  discharging  via  the  canal. 


DENTO-ALVEOLAR  ABSCESS  453 

Necrosis  and  Caries  of  Bone. — In  some  cases  the  inflammatory  reaction 
is  so  severe  that  some  of  the  bone  may  be  involved  en  masse. 

This  is  fortunately  unusual,  the  usual  result  being  a  liquefaction 
of  both  soft  and  hard  tissues.  If  it  occur  as  a  sequestrum,  tliis  gradually 
loosens,  and  either  appears  at  the  fistula  as  one  or  more  pieces,  or,  being 
found  loose,  by  instrumentation  is  worked  out,  the  fistula  being  en- 
larged if  necessary.  If  the  thorough  loosening  of  the  pieces  is  awaited, 
the  patient  should  syringe  out  the  abscess  tract  with  antiseptics,  and 
the  operator  should  see  the  case  frequently  until  the  operative  pro- 
cedure is  riecessary.    The  general  health  is  to  be  improved  if  necessary. 

Ulceration  of  an  alveolus  may  result  from  the  extraction  of  a  tooth, 
and  if  neglected  may  produce  necrosis  of  the  bone.  In  both  cases  the 
pain  is  severe  and  often  reflex.  The  condition  has  been  termed  "dry 
socket." 

If  ulcerated,  the  alveolus  is  painful  to  touch;  if  necrotic,  the  super- 
ficial bone  is  insensitive,  the  ulceration  being  more  deeply  seated  in  the 
diploeic  structure. 

The  best  and  most  radical  treatment  consists  in  antisepsis  followed 
by  the  administration  of  short  general  anesthesia,  or,  if  necessary, 
cocainization  of  the  gum  and  a  thorough  removal  of  the  superficial 
ulcerated  or  necrotic  bone  to  a  point  capable  of  healthy  granulation. 
After  injection,  a  clot  is  invited  to  fill  the  alveolus  in  order  to  stimulate 
the  condition  following  an  ordinary  extraction. 

As  an  alternative,  the  ulcerated  cases  may  be  thoroughly  saturated 
with  full  strength  trichloracetic  acid  solution,  which  acts  as  a  stimulant, 
escharotic,  and  germicide,  and  a  paste  made  from  orthoform,  zinc 
oxid,  and  vaseline  may  be  packed  into  the  alveolus.^  The  patient 
should  be  seen  not  later  than  twenty-four  hours  afterward,  and  the 
application  repeated,  or,  better,  a  clot  invited  after  further  sterihzation. 

Hydrogen  dioxid  with  mercuric  chlorid  added  (1  to  1000)  and  applied 
topically  is  effective  as  a  germicide.  In  caries  of  the  bone  a  progressive 
absorption  of  the  cancellated  bone  and  subsequent  suppuration  of  its 
marrow  results  in  a  honeycombed  mass  of  dead  bone  which  tends  to 
become  gradually  large.    It  should  be  removed  and  regeneration  invited. 

Abscesses  on  the  Temporary  Teeth. — The  treatment  of  abscess  in 
case  of  temporary  teeth  being  effected,  does  not  differ  in  principle  from 
that  in  the  permanent  teeth.  The  only  complication  is  the  state  of  the 
root  end,  whether  partially  absorbed  or  not.  A  plastic  root  filling  is 
indicated,  the  conditions  being  met  by  paraffin  or  wax  combined  with 
aristol  or  paraform.  (See  Root  Canal  Filling.)  If  the  roots  are  almost  all 
resorbed,  extraction  is  often  better  than  canal  treatment  (Fig.  527). 

Suppuration  following  Extraction. — When  the  suppurative  process  Is 
active,  whether  in  the  second  or  third  stage  or  when  a  fistula  exists, 

^  Jack,  International  Dental  Journal,  1905. 


454 


TREATMENT  AM)  FILLING  OF  ROOT  CANALS 


Fig.  527 


the  surrounding  tissue  is  sometimes  involved  to  such  an  extent  that 
whether  the  tooth  be  extrac-ted  or  not  the  process  may  continue.  It 
has  happened  tiiat  adjoining  teeth  have  been  invoked  or  that  the 
infection  may  tra\el  along  the  periosteum  and  cause  profound  and 
widesj)read  infection.  In  a  case  of  a  boy  aged  14  years,  at  present 
under  treatment,  a  right  lower  molar  was  the  starting  point  from 
which  the  infection  spread  along  the  bone,  so  that  every  lower  tooth 
from  the  right  second  molar  to  the  left  second  molar  was  profoundly 
loosened,  the  gum  detached,  and  the  chin  tissues  swollen.  Pressure 
upon  them  caused  a  copious  flow  of  ichorous  pus  from  a  number  of 
fistulse  and  gum  margins.     The  patient  suffered  from  aneurysm  due  to 

the  aseptic  intoxication.  The  case  referred 
to  the  writer  was  sent  to  a  surgeon,  who 
made  a  lineal  incision  beneath  the  rim 
of  the  jaw%  and  after  irrigation  packed 
with  antiseptic  gauze.  The  case  is  pro- 
gressing satisfactorily,  with  some  hope  of 
saving  a  fair  number  of  the  teeth,  which 
are  becoming  more  firm. 

Such  cases  illustrate  the  dangers  of  apical 
infection  and  the  necessity  for  supervision 
after  treatment  or  extraction  in  all  cases 
of  abscess.  The  removal  of  the  primary 
exciting  cause  and  active  sterilization  of 
the  parts  is  indicated.  Systemic  treatment 
should  be  conjoined. 
Non-septic  Pericementitis. — This  form  of  inflammation  of  the  peri- 
cementum is  non-infective,  and  is  due  to  some  form  of  violence  or 
chemical  irritation  of  the  pericementum  or  is  the  result  of  a  violent 
pulp  reaction  by  reason  of  v.hich  some  of  the  excess  of  blood  in  the  pulp 
finds  its  way  into  the  apical  tissue. 

In  all  cases  there  is  an  overfulness  of  blood  in  the  apical  tissue  asso- 
ciated with  swelling,  which  causes  the  tooth  to  be  somewhat  extruded, 
therefore  it  maloccludes,  which  adds  more  mechanical  irritation. 

In  so  far  as  canal  treatment  is  concerned  the  cases  may  be  divided 
into : 

1.  Those  in  which  the  violence  has  been  or  is  of  external  character, 
the  cause  not  continuing  in  action  or  being  present  only  as  malocclusion ; 
sometimes  as  a  wedge  or  regulating  appliance.  If  the  pulp  be  not 
hopelessly  involved  the  treatment  should  consist  of  rest  attained  by 
means  of  guards  to  prevent  occlusion  and  counterirritant  applications 
upon  the  gum  over  the  tooth  in  mild  cases,  distant  in  severe  ones,  or 
the  use  of  depletion  and  sedation  in  severe  cases.  As  an  oral  sedative, 
cold  aqueous  extract  of  hamamelis  is  very  useful.  Derivation  should 
also  be  employed. 


Showing  the  relations  of  an  abscess 
upon  a  temporary  tooth,  with  the 
crown  of  a  developing  permanent 
tooth  underlying  it. 


DENTO-ALVEOLAR  ABSCESS  455 

Traiunatic  ])ciMc(Mnciititis  may  cause  a  ])r()f()Uiid  s\velliii<,^  of  the  peri- 
cementum and  exti-usion  of  the  tooth  which  only  rc])hintation  will  cure. 

2.  Those  in  which  l)y  way  of  the  canal  the  ai)ical  tissue  lias  been 
lacerated  by  broaches  or  drills,  irritated  by  pressure  of  air,  canal  fillings, 
etc.,  or  chemically  irritated  by  powerful  chemical  substances.  Second- 
ary hemorrhage  after  pressure  anesthesia  and  pulp  removal  is  a  mechan- 
ical cause.  In  all  cases  such  should  be  a\'oided,  or,  if  present,  removed, 
and  sedatives,  such  as  phenol-camphor  or  eugenol,  to  which  menthol  has 
been  liberally  added,  should  be  placed  in  the  canal  on  cotton.  Counter- 
irritants  are  to  be  applied  to  the  gum  and,  if  necessary,  guards  applied 
to  prevent  occlusion. 

When  canal  fillings  have  been  carefully  made  they  sometimes  cause 
a  limited  non-septic  apical  pericementitis,  which  will  often  pass  away 
under  the  action  of  counterirritants ;  therefore  some  judgment  must 
be  exercised  as  to  the  removal  of  such  canal  fillings. 

Perforations  and  Resorptions. — The  same  accidents  that  occur  in  canal 
opening  in  the  case  of  the  remo^'al  of  anesthetized  or  devitalized  pulps 
may  occur  in  all  gangrenous  cases  with  somewhat  increased  liability 
to  infection  of  the  pericemental  tissue. 

In  old  cases  the  pericemental  tissue  may  hypertrophy,  causing  the 
condition  of  hyperplastic  (fungoid)  gum.  This  should  be  sterilized  and 
then  may  be  frozen  with  ethyl  chlorid  and  ablated  with  sharp  instru- 
ments, or  it  may  be  saturated  with  trichloracetic  acid  and  ablated,  or 
it  may  be  pressed  away  (resorbed)  with  cotton  saturated  with  tincture 
of  iodin  or  an  antiseptic  oil.    The  perforation  is  then  covered. 

The  Filling  of  Perforations. — Perforations  made  high  up  in  the  canal, 
after  being  appropriately  sterilized  "^^dth  formocresol,  should  be  filled 
with  wax  or  with  gutta-percha  cones,  which 
have  been  accurately  fitted  to  the  openings.  ^'°-  °-^ 

It  is  often  difficult  to  do  this,  but  the  effort 
should  be  made.  When  ready,  a  little  anti- 
septic chloropercha  is  to  be  placed  in  the 
perforation  or  upon  the  cone,  and  the  latter 
packed  to  place. 

In  low  perforations  without  a  fistula  asso- 
ciated, the  opening  of  the  perforation  should 

.  .  iin  1  p  Idiopathic    resorption  of   perma- 

be  enlarged  mwardly  and  a  ball  or  plaque  or     neat  root.    The  bay  upon  the  side 
aseptic,  warm,  low  heat  gutta-percha,  or  even     exposed  the  puip  and  perforated 

'111  •  ^^^    root    as   shown.       Crater-hke 

temporary  Stoppmg,  adapted  to  tne  Openmg.        resorption    about    apical    foramen. 

A  piece  of  pure  gold  plate  mav  be  burnished     p^'p  ^''^  de^atalized  on  account  of 

r^.  '  persistent  pain  and  the  tooth    later 

over  an  accessible  openmg,  and  be  adapted     extracted. 
with  thick  chloropercha  or  temporary  stop- 
ping.    Any  of  these  may  be  fixed  in  place  with  ox^'phosphate  of  zinc. 
Quick-setting  ox\T3hosphate  of  copper  in  its  soft,  gummy  state  may  be 
painted  over  the  tissue  and  root  opening  by  means  of  an  instrument. 


450  TREATMENT  A\D  FILLIXO  OF  ROOT  CANALS 

or  the  perforation  may  often  be  satisfactorily  closed  with  copper 
amai^^am.  When  in  ])()steri()r  teeth  a  pin  must  be  used,  the  pin  may  be 
made  smaller  than  the  root  canal  and  be  coated  with  wax,  soft  oxy- 
phosphate  of  copper  is  put  in  the  canal,  and  the  pin  gently  thrust  in. 
When  the  cement  has  set  the  pin  may  be  heated  and  withdrawn,  and 
when  included  in  the  intended  superstructure,  the  pin  may  be  again 
cemented  in  place. 

When  a  perforation  threatens  to  produce  an  abscess  an  artificial 
fistula  should  be  made  and  the  case  treated  as  described  on  page  447. 

If  a  perforation  have  a  fistula  associated  with  it,  the  ox;s'phosphate 
of  copper  may  be  allowed  to  go  through  the  fistula,  by  way  of  which  any 
excess  may  be  removed. 

In  case  of  resorption  of  the  roots  of  permanent  teeth  great  difficulty 
may  present,  the  soft,  absorbent  tissue  having  grown  into  the  cavity  in 
the  root  side  which  it  has  made.  A  radiograjjli  will  aid  in  determining 
the  extent  of  the  lesion,  which  usually  renders  canal  treatment  impossible 
and  extraction  imperative. 

THE  FILLING  OF  ROOT  CANALS 

In  all  cases  in  which  the  removal  of  the  dental  pulp  from  the  canals 
is  necessary,  it  is  imperative  that  the  pulp  canals  shall  be  filled  with 
some  substance  that  shall  mechanically  obliterate  it  by  sealing  it 
throughout  its  length  in  order  to  prevent  the  ingress  of  fluid  either 
from  the  mouth  or  apical  tissue.  Such  fluid  is  liable  to  putrefaction, 
and  the  results  of  putrefaction  follow.  If  made  antiseptic,  it  also 
tends  to  kill  any  bacteria  which  may  find  a  partial  entrance.  The 
mechanical  sealing  may  be  defective,  even  when  the  best  possible 
effort  has  been  put  forth  to  make  it  perfect,  so  that  the  addition  of 
more  or  less  permanent  antiseptics  is  valuable. 

It  matters  little  whether  a  canal  filling  is  hard  or  soft  provided  it  is 
permanent,  that  the  above  conditions  are  fulfilled,  and  that  it  is  not 
disturbed  by  any  subsequent  work. 

It  also  makes  very  little  difference  whether  the  pulp  has  been  removed 
while  aseptic  or  has  been  in  a  septic  state,  provided  the  canal  has  been 
rendered  sterile  by  appropriate  means. 

In  other  words,  when  the  canal  is  aseptic  and  the  apical  tissues 
sterile  and  healthy,  the  canal  is  ready  for  filling.  The  length  of  time 
this  may  require  also  makes  no  difference  The  size  of  the  apical  foramen, 
the  presence  of  inaccessible  apical  portions  of  canals,  the  presence  of 
perforations  and  some  other  conditions,  however,  indicate  a  choice  of 
some  root  filling  rather  than  others,  so  that  there  is  no  absolute  rule  for 
all  cases.     The  following  root  canal  fillings  are  useful. 

Gutta-percha.— This  is  usually  the  ordinary,  low  heat,  pink  gutta- 
percha base-plate  containing  vermilion  and  zinc  oxid.     Cones  may  be 


THE  FILLING  OF  ROOT  CANALS  457 

rolled  or  left  with  flat  sides.  Prepared  cones  may  be  purchased  which 
lia\'e  an  accurate  taper  and  are  either  round-  or  flat-sided.  The  flat  side 
permits  any  adjunct  j)lastic  filling  material  or  solvent  to  flow  down  the 
side  of  the  cone  rather  than  be  forced  toward  the  apex. 

Temporary  stopping  may  be  melted  in  a  spoon  and  aristol  added 
to  it.  It  is  then  rolled  into  cones  for  use.  Instead,  a  stick  of  it  may 
be  warmed  at  a  point  away  from  the  end  and  then  be  pulled  out  into 
two  cones,  which  may  be  further  rolled  out.  They  may  be  rolled  in 
powdered  aristol  if  desired. 

Chloropercha. — This  is  a  solution  of  gutta-percha  base-plate  in  chloro- 
form. Usually  a  quantity  of  aristol  or  iodoform  is  added  to  make  it 
antiseptic.  As  it  shrinks  in  hardening  it  should  be  used  in  conjunction 
with  gutta-percha  cones  or  carried  upon  cotton  twist  or  floss  silk,  which 
it  satiu*ates,  transforming  them  practically  into  a  solid  mass  when  the 
chloroform  evaporates. 

Eucolypto-percha  (Eucapercha). — The  basis  of  this  substance  is  a 
solution  of  gutta-percha  base-plate  in  eucalj^tol.  To  this  various 
antiseptics  may  be  added.  There  are  various  modes  of  making  this 
substance.    B.  L.  Cochran^  susrsrests  the  followins;: 


*&&^ 


I^ — Gutta-percha  base-plate 5ss 

Dissolve  in  chloroform  q.  s.  to  a  thin  solution.    Add  satu- 
rated solution  of  thj^mol  in  eucalyptol f  o  ss 

Let  the  chloroform  evaporate. 

Eucapercha  Compound  (Buckley  Lilly)  is  a  simple  solution  of  base- 
plate in  eucalyptol  made  by  aid  of  heat. 

Formopercha  (Blair)  has  paraform  and  oil  of  cassia  added. 

This  material  may  be  warmed  into  a  creamy  paste  and  be  used  either 
on  cotton  or  be  used  in  conjunction  with  gutta-percha  cones. 

Zinc  Oxychlorid. — This  consists  of  the  ordinary  zinc  oxychlorid  cement, 
which  consists  of  modified  calcined  zinc  oxid  for  the  powder  and  diluted 
zinc  chlorid  as  the  fluid. 

It  is  antiseptic  for  a  time  at  least,  and  may  have  iodoform  incorporated 
with  it  if  desired.  It  is  carried  to  place  on  a  thread  of  cotton,  or  may 
be  used  with  gutta-percha  cones.  The  addition  of  a  trifle  of  glycerin 
retards  setting. 

A  so-called  embalming  paste  is  prepared  as  follows : 

I^ — Paraform 1  part 

Thymol 1  part 

Glycerin 1  part 

Zinc  oxid 1  part  or  more 

Or, 

I^ — Paraform 1  part 

Thymol 2  parts 

Alum 1  part 

Zinc  oxid 2  parts 

Creosote  to  a  thick  or  thin  paste. 

1  Dental  Review,  1905. 


458 


TRKATMKXT  AXD  FILLIXG  OF  ROOT  CANALS 


This  is  used  as  a  temporary  ^MTiiiicidal  canal  (lr('ssiii<^  on  cotton  or 
as  a  I'oot  fillini;  with  gutta-percha  or  tcinj)orary  stopping  cones  which 
arc  j)resse(l  into  it. 


l''i(j.  5li'J 


Fio.  530 


a,  root  j)()rti()n  of  pulp;  6.  mummifying  paste;  r,  zino 
pliusphate;  d,  gold  or  ainalgaia. 


Root-oanal  filling:    A,  gutta-percha; 
B,  zinc  oxychlorid. 


Wax  or  Paraffin. — Either  of  these  may  have  a  third  of  its  bulk  of 
salol,  aristol,  or  iodoform,  or  a  fifth  of  paraform  added  to  it  while  melted 
iu  a  spoon.  It  is  then  rolled  into  cones  or  small  pellets.  In  use  a  pellet 
is  dropped  into  the  dried  pulp  chamber  and  a  hot  Evans  root  drier 
point  applied.  As  it  melts,  the  metal  point  is  carried  down  into  the 
root  and  the  fluid  material  pumped  to  the  apex.  Capillarity  does 
part  of  the  work.  It  adjusts  itself  to  the  tissue  and  the  canal  walls. 
The  pulp  chamber  is  then  cleared  of  excess  wax,  etc.,  and  filled  without 
pressure. 


Fig.  531 


Fig.  532 


A,  perforation  through  side  of  apex;  D,  cone 
of  gutta-pereha  passing  through;  B,  portion  t( 
1)('  cut  olT;  C,  portion  of  canal  not  treated. 


I^ateral  perforation  due  to  holding  a  bur  at  a 
wrong  angle  to  the  axis  of  the  root:  .4,  root 
canal  subsequently  filled  with  gutta-peroha;  B, 
perforation  filled  with  a  fitted  cone  of  gutta- 
percha;   (',  zinc  oxychlorid. 


Salol.— This  is  a  solid  antiseptic,  melting  at  104°  F.  It  is  u.sed  much 
as  paraffin  is.  A  gutta-percha  cone  may  be  thrust  into  it  while  fluid. 
It  often  seems  to  disappear  from  canals,  and  unless  used  with  paraffin 
is  to  be  used  only  as  a  temporary  root  filling. 

Canada  Balsam. — A  solution  of  Canada  balsam  in  chloroform  to  which 
hydronaphthol  is  adtled  (\Yilliams)  makes  a  useful  solution  in  which 


Tlll<:  Fll.LISd  OF  HOOT  CANALS  459 

to  saturcito  cotton  twists  or  to  iiioistcii  canals  previous  totlic  introduc- 
tion of  a  cone  of  gutta-percha. 

Normal  Tapering  Well-opened  Canals. — In  tlicse  canals  gutta-percha 
is  admirable;  a  little  eucalyptol  is  api)lied  to  the  canal  walls  and  a 
section  of  a  suitable  cone  mounted  by  heat  on  the  end  of  a  canal  plugger 
which  will  go  to  or  nearly  to  the  canal  end  is  gently  but  firmly  pressed 
into  the  apex  of  the  canal.  Temporary  stopping  cones  are  more 
readily  adapted,  and  as  they  can  be  made  antiseptic,  are  valuable. 

The  rest  of  the  canal  is  then  filled  with  otlier  sections  or  with  zinc 
oxychlorid  made  thin  and  carried  to  place  on  cotton  twists.  The  latter 
may  be  used  for  the  entire  canal,  and  should  then  be  preceded  by  a 
tiny  bit  of  cotton  saturated  with  an  essential  oil  to  prevent  irritation 
of  the  apical  tissue.  It  is  claimed  that  this  cotton  is  acted  upon  by 
the  zinc  chlorid  being  transformed  into  an  amyloid  condition. 

A  variant  consists  in  moistening  the  canal  with  chloropercha  or 
eucalypto-percha,  and  using  the  section  of  cone  or  pressing  in  an  entire 
cone.  A  second  cone  may  be  placed  at  the  side  of  the  first  and  both 
compacted  after  w^arming  with  a  hot  air  blast,  or  the  first  cone  alone 
used. 

Ottolengui  advises  the  use  of  bits  of  floss  silk  an  inch  long  to  be 
saturated  with  chloropercha  and  dried.  These  are  to  be  pressed  into 
chloropercha  previously  placed  in  the  canal  and  crimped  to  place.  An 
end  is  left  projecting  into  the  pulp  chamber.  If  necessary  this  may  be 
caught  and  the  dressing  withdrawn. 

Another  variant  is  the  use  of  chloropercha  on  cotton,  which  makes 
a  very  accurate  and  easily  introduced  root  filling  when  carried  to 
place  on  a  properly  formed  and  tempered  Swiss  broach  or  prepared 
Donaldson  bristle. 

When  the  broach  must  be  bent  to  enter  canals,  loosen  the  broach  first 
before  introducing  into  the  canal,  thus  leaving  the  cotton  loosely  mounted 
on  the  broach.  To  prepare  a  Donaldson  bristle  cut  off  the  hook  and 
flatten  the  end  upon  an  Arkansas  stone,  then  lay  upon  a  glass  slab 
and  burnish  thoroughly  to  remove  any  bur  left.  In  use  the  cotton 
and  broach  are  rolled  with  the  left  forefinger  and  thumb  only.  It  is 
obvious  that  to  do  this  the  broach  must  be  perfectly  straight.  The 
writer  believes  the  prepared  Swiss  broach  not  only  more  facile  but 
economical  in  use. 

To  prepare  broaches,  select  accurately  tapering  Swiss  or  English 
broaches  from  which  the  temper  has  not  been  drawn.  Next,  draw  the 
temper  to  a  blue  color  by  placing  a  few  in  a  test-tube  and  heating  first 
at  the  shank,  gradually  drawing  the  tube  over  the  flame  toward  the 
points;  let  cool  on  any  open  surface.  The  point  is  left  if  canal  explora- 
tion is  intended.  For  carrying  cotton  twists,  cut  the  end  off  with  scissors. 
To  wind  the  cotton  lay  a  wisp  on  the  left  forefinger,  lay  the  broach  upon 
it,  close  down  the  thumb,  then  quickly  revolve  the  broach  with  the 


4(i()  TREATMENT  AXJ)  FILLINd  OF  ROOT  CANALS 

ri^^lit  forefinger  and  thumb,  stroking  the  cotton  with  those  of  the  left 
hand  into  a  symmetrical  cone.  To  use  as  a  swab,  rotate  in  the  canal 
to  the  right.  To  leave  the  cotton  in  the  canal,  rotate  to  the  right  as 
the  twist  is  pressed  to  the  aj)ex.  Tlien  turn  the  broach  once  or  twice  to 
the  left  to  loosen  it  from  the  cotton,  withdraw  a  little,  then  press  in  again. 
Thus  the  cotton  is  crimped  upon  itself. 

Roots  with  Open  Foramina. — These  may  be  incomplete  roots  with 
very  large  apical  openings,  in  which  case  wax  with  aristol  is  the  b(^t 
filling  used,  as  previously  stated.  It  should  be  said  again,  however, 
that  if  possible  the  pulps  of  such  a  tooth  should  be  cai)pcd  to  permit 
root  formation  to  be  completed. 

If  the  foramen  is  of  moderate  extent  and  either  natural  or  unfortu- 
nately made  with  drills,  gutta-percha  cones  are  valuable.  To  determine 
the  size  of  the  cone,  one  of  two  methods  may  be  employed.  Perhaps 
the  more  accurate  is  the  employment  of  a  series  of  gradually  increasing 
sizes  of  canal  pluggers.  One  should  be  selected  which  will  just  fit  the 
apex  or  be  a  trifle  too  large.  By  placing  this  in  the  hole  of  a  draw 
plate,  a  specially  rolled  cone  or  even  a  slightly  tapering  size  may  be 
made  to  fit  the  hole  in  the  plate.  The  canal  is  moistened  with  euca- 
lyptol  or  chloropercha  and  a  quarter-inch  section  of  the  cone  is  carried 
on  the  plugger  to  its  place  in  the  root  canal  apex.  A  slight  protrusion 
is  not  ordinarily  productive  of  injury.  A  cardboard  perforated  by 
the  respective  plugger  will  do  instead  of  the  draw-plate.  If  the  root 
length  was  previously  measured  with  a  piece  of  rubber  dam  slipped 
over  the  plugger  shank  and  some  known  point  on  the  tooth  used  as  a 
guide,  the  cone  should  be  seen  to  go  down  until  it  chokes  the  foramen, 
when  the  dam  should  be  above  the  guide  point  a  distance  equal  to  the 
length  of  the  cone  section  used. 

In  the  second  method  a  long,  tapering  cone  is  prepared.  Some 
point  on  this  must  fit  the  foramen.  It  is  tried  in  and  as  often  as  sensa- 
tion is  felt  it  is  cut  off  a  trifle  and  tried  again  until  it  chokes  the  foramen 
without  sensation. 

In  case  of  abscess,  especially  if  filling  is  a  means  to  a  cure,  this  may 
extend  beyond  the  apex  of  the  tooth. 

The  cone  should  be  marked  at  a  point  corresponding  to  the  guide 
point  chosen  and  laid  aside.  Next,  a  fine  hook  made  by  bending 
the  tip  of  a  fine  broach  to  a  right  angle,  then  cutting  it  close  to  the 
shank,  has  a  piece  of  rubber  dam  slipped  over  it  and  is  passed  through 
the  apex  and  hooked  upon  the  edge  (Fig.  533).  The  dam  is  slipped  to 
the  chosen  guide  point.  The  probe  hook  is  withdrawn,  the  dam  laid 
at  the  mark  on  the  cone,  and  the  cone  cut  off  at  the  lower  edge  of  the 
hook  (Fig.  533,  h).  In  use,  a  little  solvent,  preferably  chloropercha,  is 
placed  in  the  canal  and  the  cone  slowly  slipped  to  place  until  the  mark 
coincides  with  the  guide  point.  The  cone  is  then  cut  off  with  a  hot  instru- 
ment, warmed,  and  gently  packed  into  the  canal. 


THE  FILLING  OF  ROOT  CANALS 


461 


WIr'ii  tlie  Ciiiuil  Ikis  bocu  reamed  with  a  small  oiigiue  reamer,  and 
the  apex  enlarged,  the  hook  may  be  plaeed  and  have  a  bit  of  rubber 
dam  on  it  as  a  guide.  Then  slip  a  bit  of  dam  over  a  hirger  tapering 
root  reamer  at  a  corresponding  length.  Drive  the  reamer  in  until  at 
the  guide  point.  This  gives  a  tapering  cone  shape  to  the  canal  and  is  a 
guide  in  the  construction  of  the  cone  (P'ig.  534). 


Fig.  534 


-d 


Maimer  of  measuring  t}ie  length  of  a  root 
and  fitting  a  gutta-percha  cone. 


-a 


Manner  of  tapering  a  canal  to  fit  a  cone 
of  the  same  size. 


Canals  with  Inaccessible  Apices. — Any  tissue  in  such  apices  should 
have  been  mummified  or  sterilized  with  formocresol  or  be  treated 
by  Rhein's  method^  of  filling  a  canal  with  mercuric  chlorid  in  hydro- 
gen dioxid  (1  to  500),  passing  in  a  zinc  probe,  then  applying  the 
anode  of  a  cataphoric  outfit  with  from  1  to  5  milliamperes  of  current 
from  three  to  seven  minutes  (the  cathode  at  the  cheek).  The  object 
is  to  form  zinc  oxychlorid  in  the  apical  root  canal  through  electro- 
lytic action.  The  canal  must  be  regarded  as  doubtful,  but  if  well 
opened  to  the  inaccessible  portion  a  trifle  of  formopercha  may  be  placed 
on  cotton  at  this  point  and  the  balance  of  the  canal  be  filled  with  anti- 
septic temporary  stopping.  The  paraform  and  cassia  in  the  formo- 
percha are  active  agents. 

A  variant  consists  in  the  use  of  embalming  paste  or  Soderberg's 
mummifying  paste,  either  made  stiff  and  introduced  with  successive 
sizes  of  pluggers,  beginning  with  the  largest  admissible  and  proceeding 
to  the  smallest,  or  moistening  the  canal  with  the  thinner  paste  and 
packing  a  cone  into  it.  The  use  of  such  a  paste  in  connection  wdth  a 
cone  of  gutta-percha  is  valuable  as  an  agent  embalming  the  fibrils  in 
the  dentin  of  teeth  from  which  Hving  pulps  have  been  removed,  or  of 
keeping  sterile  the  tubules  of  those  teeth  in  which  the  pulp  is  gangrenous. 

If  conditions  admit  of  it,  provision  for  future  entrance  of  the  canals 


»  Dental  Cosmos,  1905,  p.  1196. 


462  TREATMENT  AND  FILLINC;  OF  ROOT  CANALS 

should  be  made,  and  it  is  always  well  to  divide  the  operation  of  canal 
fillin<]c  and  crown  filling  by  a  short  period  of  time. 

Iodoform  paste  with  or  without  cotton  may  be  placed  in  the  u})per 
third  of  the  canal. 

Root  Canals  in  Temporary  Teeth. — These  may  at  times  be  well  filled 
with  gutta-percha  points,  which,  if  aseptic,  do  not  interfere  with  resorp- 
tion, but  a  material  of  easier  adaptation  which  absorbs  with  the  root 
is  preferable.  The  waxes  meet  the  indications,  as  they  can  be  pumped 
while  fluid  from  the  action  of  a  hot  root  drier  into  all  inequalities,  where 
they  adjust  their  relation  to  the  soft  tissue. 

Buckley  recommends  in  cases  of  chronic  abscess  the  use  of  a  stiff 
mixture  of  calcium  phosphate  and  formocresol  (formalin,  1  part;cresol, 
2  parts),  to  be  packed  into  the  pulp  cavity  and  zinc  phosphate  flowed 
over  it. 

Johnson  recommends  eucalypto-percha  to  be  pumped  into  the  canals 
and  pressure  with  temporary  stopping  to  be  exerted  until  the  solution 
appears  at  the  fistula.  Such  temporary  stopping  as  does  not  interfere 
with  filling  integrity  should  be  left. 

There  are  various  other  methods  of  filling  root  canals,  such  as  driving 
wood  points  saturated  in  carbolic  acid  into  the  canals;  the  use  of  iodo- 
form paste  with  or  without  cotton,  or  of  creosote  on  cotton  (preferably 
raw  cotton) ;  the  use  of  balsam  del  deserto,  etc.,  which  have  advocates, 
but  the  methods  given  are  those  which  have  had  long-continued  and 
successful  use. 

The  Covering  of  the  Root  Canal  Filling. — The  bulb  of  the  pulp  chamber 
may  be  filled  with  any  of  the  more  solid  materials.  In  case  of  a  strong 
crown,  temporary  stopping  makes  a  good  occupant  of  this  cavity, 
although  gutta-percha  is  often  used.  In  the  weaker  teeth  or  sometimes 
for  other  reasons  zinc  oxychlorid  or  zinc  phosphate  with  about  5  per 
cent,  of  thymol  added  while  mixing  makes  a  good  filling. 

Mummification  of  the  Pulp. — In  order  that  time  may  be  saved,  efforts 
have  been  made  to  introduce  partial  remo\'al  of  the  pulp  and  the  treat- 
ment of  the  remaining  portion  by  means  of  drying  agents  which  shall 
render  it  less  liable  to  putrefaction.  The  method  had  its  origin  with 
Witzel  in  1874,  and  has  since  been  taken  up  by  IVIiller  (1893)  and 
Soderberg  (1895). 

It  consists  of  partial  devitalization  by  arsenic  and  the  application  of 
a  tanning  agent  against  the  pulp  stumps.  Necessarily  this  causes  the 
shrinkage  of  the  organ,  leaving  a  space  about  it  into  which  bacteria  may 
possibly  find  their  way.  Obviously  the  nearer  the  apex  of  the  pulp  canal 
this  is  carried,  the  less  the  danger  of  subsequent  infection.  Therefore 
the  logical  conclusion  is  that  all  remnants  of  pulp  that  can  be  removed 
should  be  removed,  when  a  tanning  and  antiseptic  agent  that  will 
occupy  the  canal  becomes  an  excellent  root  filling.  There  is  little 
excuse  for  not  carrying  the  canal  work  to  this  point,  as  the  present 


THE  FILLING  OF  ROOT  CANALH  4(J3 

methods  of  canal  enlargement  render  it  facile.     In  some  cases,  how- 
e^'er,  Soderberg's  method  may  be  of  use. 

It  consists  in  applying  arsenic  for  a  short  time  to  devitalize  the  j)ulp 
bulb  only,  then  applying  a  portion  of  the  following  i)aste  to  the  i)uli) 
stumps : 

I^ — Aluminis  exsiccatis, 
Thymolis, 

Glycerini aa     oj 

Zinci  oxidi,  q.  s.  to  make  a  stiff  paste. 

This  is  then  covered  with  zinc  phosphate  and  the  filing  completed. 
A  crystal  of  cocain  may  be  added  to  prevent  pain.  It  has  been  suggested 
that  paraform  or  a  drop  of  liquor  f ormaldehyd  be  added  for  the  increased 
mummifying  effect. 

Pulp  Digestion. — Harlan  recommended  that  the  following  paste  be 
applied  to  unremoved  portions  of  dead  pulps  as  a  means  of  digesting 
them  preparatory  to  root  filling: 

I^ — Papain gr.  V 

Price's  pure  glycerin TTliv 

Sol.  1  :  200  hydrochloric  acid HIv— M. 

This  is  applied  in  the  pulp  canal,  covered  with  blotting  paper,  soaked 
in  liquid  vaselin,  and  the  whole  temporarily  sealed  for  a  few  days. 
The  pulp  is  reduced  to  the  consistence  of  jelly  and  can  be  readily  washed 
out. 

The  method,  on  the  whole,  does  not  seem  preferable  to  either  mummi- 
fication or  the  Rhein  treatment  or  the  formocresol  treatment  of  inex- 
tricable portions  of  pulps  in  curved  roots,  etc.,  inasmuch  as  the  occupancy 
of  a  canal  by  a  sterile  pulp  remnant  is  better  than  leaving  an  empty 
root  canal  apex  or  filling  only  a  portion  of  it  in  such  manner  as  to  render 
subsequent  treatment  almost  impossible.  In  fact,  it  is  better  that  den- 
tists recognize  their  limitations  and  put  themselves  in  position  to  do 
future  good  to  the  patient,  than  to  blindly  obstruct  efforts  in  that 
direction. 


CHAPTER    XV 
PYORRHEA  ALVEOLARIS' 
By  EDWARD  C.  KIRK,  D.D.S.,  Sc.D. 

Definition. — "Pyorrhea  alveolaris"  is  a  generic  term  which,  strictly 
defined,  means  a  flowing  of  pus  from  an  alveolus.  It  describes  merely 
a  sj'mptom  which  is  usually,  but  not  invariably,  attendant  upon  a 
variety  of  gingival  disorders.  The  term  is  applied  in  clinical  dentistry 
to  a  complexus  of  pathological  conditions  which  more  or  less  clearly 
indicate  a  specific  disease.  As  now  understood,  the  term  pyorrhea 
alveolaris  includes  those  cases  of  morbid  action  characterized  by  the 
following  features:  Inflammatory  degenerative  changes  leading  to  a 
molecular  necrosis  of  the  retentive  structures  of  the  teeth  (their  liga- 
ment, the  pericementum),  an  atrophy  of  the  aheolar  walls,  together 
with  a  chronic  hyperemia  of  the  gum  tissue.  After  a  variable  period 
the  teeth  drop  out,  and  the  morbid  action  ceases  with  their  loss.  An 
examination  of  the  roots  of  the  teeth  before  or  after  their  exfoliation 
usually,  though  not  invariably,  exhibits  deposits  of  calculi  upon  their 
surfaces.  The  disease  is  generally,  although  not  always,  attended  by 
a  flow  of  ])us  from  the  alveoli. 

History. — That  pyorrhea  alveolaris  is  not  a  recent  disease,  or  one 
due  to  modern  constitutional  states  alone,  is  rendered  evident  from  the 
examination  of  the  skulls  of  ancient  as  well  as  modern  races.  The 
alveolar  processes  of  many  crania  widely  separated  both  in  time  and  in 
locality  exhibit  marked  impairment  of  structure  which  bears  the  closest 
resemblance  to  that  presented  by  processes  which  are  known  to  ha\'e 
been  the  result  of  pyorrhea  during  life. 

Recorded  observations  of  this  disorder  date  at  least  as  far  back  as 
1728,  when  Pierre  Fauchard  described  its  essential  clinical  features,  but 
failed  to  designate  it  by  any  specific  term.  Following  this,  communica- 
tions describing  the  disease  were  published  by  Jourdain  in  1778,  by 
Toirac  in  1823,  and  by  M.  IMarechal  de  Calvi  in  18G0,  in  which  it  was 
described  as  a  "conjoint  suppuration  of  the  gums  and  alveoli,"  yijorrhee 
intcr-ahcolo-dentaire  and  yimjliuiis  expuJ.siva  respectively. 

'  The  historical  portion  of  this  chapter  and  the  definition  of  the  disorder,  with 
some  modification  of  the  latter,  is  the  work  of  the  late  Prof.  C.  N.  Peirce. 
(464) 


HISTORY  465 

The  most  important  coutributiou  to  the  knowledge  of  the  nature  of 
the  disease  which  had  up  to  that  date  been  made  was  by  Dr.  E.  Magitot 
in  1867.  In  his  paper  he  describes  the  disease  as  being  characterized 
by  a  slow  but  progressive  inflammation  destructive  of  the  periosteal 
membrane  and  cementum,  ])r()ceeding  from  the  neck  to  the  apex  of  the 
root  and  in\'olving  the  loss  of  the  teeth.  From  the  exact  seat  of  the 
lesion  he  designated  the  disease  osteo-'periostite  alveolo-denfaire.  Soon 
after  the  appearance  of  the  periosteal  inflammation,  it  becomes  compli- 
cated with  diseases  of  the  gums  and  the  osseous  walls  of  the  alveolus, 
although  these  are  never  primarily  the  seat  of  inflammation.  Magitot 
regarded  the  causes  of  the  inflammation  as  very  complex,  and  to  be 
sought  for  not  in  the  teeth  and  gums,  but  in  certain  conditions  of  the 
general  nutrition.  The  gouty  and  rheumatic  presented  the  disease  most 
frequently,  although  its  presence  in  those  suffering  from  diabetes  and 
albuminuiia  was  extremely  common.  The  deposition  of  tartar  on  the 
roots  of  the  teeth,  which  might  at  first  glance  be  regarded  as  playing  an 
important  part  in  the  causation  of  the  disease,  Magitot  considered  as 
accidental  and  not  to  be  looked  upon  as  a  causati\'e  agent.  With  refer- 
ence to  the  efficacy  of  any  treatment,  however,  he  advised  the  removal 
of  the  tartar  as  an  indispensable  preliminary.  The  points  of  diagnosis 
differentiating  between  this  condition  and  the  former,  that  of  gingivitis, 
however  severe,  were  also  clearly  recognized  and  noted. 

Following  ]\Iagitot's  able  paper  Mas  one  by  Serran  in  1880,  in  which 
the  author  took  exception  to  certain  of  Magitot's  views,  as  well  as  to  the 
term  by  which  the  latter  proposed  to  designate  the  disease.  He  recog- 
nized, however,  that  the  disease  was  most  common  in  middle  life  and 
occurred  principally  among  the  gouty,  the  diabetic,  and  the  albuminuric. 
He  believed  that  the  primary  manifestation  was  a  local  congestion  of 
the  gums,  followed  by  an  exudation  into  the  peridental  membrane  which 
destroyed  its  vitality  and  led  to  the  formation  of  pus  and  all  the  other 
symptoms  and  pathological  conditions  characteristic  of  the  disease. 
A  commission  composed  of  MM.  Despres,  Delens,  and  Magitot  was 
appointed  by  the  Societe  de  Chirurgie  of  Paris  to  consider  the  state- 
ments of  Dr.  Serran.  In  this  report^  they  denied  the  gingival  origin  of 
the  disease,  and  stated  their  belief  that  the  periosteal  membrane  and 
the  cementum  were  the  primary  anatomical  seat  of  the  lesion;  that  the 
succession  of  morbid  phenomena  completely  precluded  the  idea  of  an 
initial  gingivitis;  that  the  disease  begins  without  any  trace  of  conges- 
tion of  the  gums;  that  after  its  formation  the  pus  burrows  toward  the 
gingival   border,    w^hich   it   detaches — without,   however,   for   a  time 

^  Bulletins  et  Memoirs  de  la  Societe  de  Chirurgie,  tome  vi,  p.  411, 
30 


4(56  PYORRHEA   ALVEOLARIS 

destroying  its  normal  aspect;  that  only  after  considerable  augmentation 
of  the  flow  of  pus  and  the  loosening  of  the  teeth  do  the  gums  become 
imphcated;  that  the  disease  had  nothing  in  common  with  the  hypothesis 
of  a  gingival  malady,  and  that  it  is  most  frequently  a  manifestation  of 
a  general  state,  or  a  diathesis. 

These  were  the  views  entertained  and  published  by  French  surgeons 
on  the  nature  of  "  pyorrhea  alveolaris"  about  the  period  when  the  dis- 
ease began  to  receive  consideration  from  American  dentists.  Although 
pyorrhea  alveolaris  had  long  been  recognized  in  the  United  States  and 
various  observations  regarding  its  pathology  and  treatment  had  been 
published,  it  was  not  until  Dr.  John  W.  Riggs,  of  Hartford,  Conn.,  in 
October,  1875,  read  a  paper  before  the  American  Academy  of  Dental 
Surgery,  entitled  "Suppurative  Inflammation  of  the  Gums  and  Absorp- 
tion of  the  Gums  and  Alveolar  Processes,"  that  the  disease  began  to 
attract  the  attention  its  gravity  merited.  Notwithstanding  the  views 
entertained  by  Magitot  and  others  regarding  the  constitutional  character 
of  the  disease.  Dr.  Riggs  in  his  communication^  emphatically  denied 
that  the  disease  is  an  affection  of  the  bone  or  of  the  gums,  or  that  it  is 
hereditary  or  constitutional,  but,  on  the  contrary,  that  it  is  the  roughened 
teeth  themselves,  in  consequence  of  the  accretions  from  whatever  source 
derived,  which  are  the  exciting  cause  of  the  inflammation;  that  it  is 
purely  local  in  origin,  the  result  of  concretions  near  and  under  the  free 
margins  of  the  gums,  the  removal  of  which  even  in  the  third  stage  is 
followed  by  cure. 

In  1877  Dr.  F.  H.  RehwinkeP  entered  his  protest  against  the  theory 
of  the  local  origin  of  the  disease,  and  endeavored  to  pro^•e  that  it  not 
only  may  but  does  exist  independently  of  foreign  deposit  and  must 
depend  on  other  than  merely  local  causes,  and  that  it  is  an  hereditary 
and  constitutional  disease. 

Dr.  L.  C.  Ingersoll,  in  1881,  published  a  paper  entitled  "Sanguinary 
Calculus,"'^  in  wliich  it  was  stated  that  the  persistent  flow  and  discharge 
of  pus  along  the  side  of  the  tooth  was  caused  by  an  inflammation  and 
ulceration  at  or  near  the  apex  of  the  root;  as  a  result  of  which  molecular 
death  the  liquor  sanguinis  escaped  from  the  bloodvessels  into  the 
surrounding  tissues  and  became  disorganized,  the  lime  salts  crystal- 
lized on  the  surface  of  the  roots,  and  formed  the  deposit  which  from  its 
origin  he  designated  "  sanguinary  calculus."  This  deposition  he  regarded 
as  entirely  distinct  from  sahvary  calculus,  and  as  derived  from  the 

'  Pennsylvania  Journal  of  Dontal  Science,  vol.  iii,  p.  00. 

"^  Report  of  the  Conmiittce  on  Pathology  and  Surgery,  Tran.s.  American  Dental 
Association,  1877,  p.  06. 

^  Ohio  State  Journal  of  Dental  Science,  ^  ol.  i,  p.  189. 


HISTORY  407 

blood — the  result  of  inflammatory  action  and  not  its  cause.  In  other 
words,  he  held  that  pyorrhea  is  a  local  disease  but  beginning  centrally; 
that  is,  at  or  near  the  apex  of  the  root. 

In  1SS2  Dr.  A.  Witzel  read  a  paper  before  the  German  Society  of 
Dentists,^  in  which  it  was  asserted  that  the  primary  pathological  change 
was  an  inflammation  and  caries  of  the  alveolar  border  followed  by  a 
deposit  just  beneath  the  free  margins  of  the  gums,  which  became  re- 
tracted and  re\'erted.  The  entrance  of  micro-organisms  into  this  carious 
region  developed  pus  which  became  more  or  less  infectious.  In  conse- 
quence he  termed  the  disease  "infectious  alveolitis."  He  regarded  the 
disease  as  a  primary  local  ah'eolitis,  having  no  constitutional  relations 
whatever,  a  molecular  necrosis  of  the  alveoli  or  caries  of  the  dental 
sockets  produced  by  septic  irritation  of  the  medulla  of  the  bone. 

In  1886  Dr.  G.  V.  Black  prepared  probably  the  most  exhaustive 
paper  in  print  in  the  United  States,  wherein  pyorrhea  alveolaris  is 
treated  as  a  local  disturbance.-  Calcic  inflammation  and  phagedenic 
pericementitis  are  the  terms  he  employs  to  indicate  its  character. 
Although  he  believes  it  to  be  wholly  local,  he  thinks  a  serumal  or  san- 
guinary deposit  may  be  closely  allied  with  its  origin.  He  describes  it 
as  a  destructive  inflammation  of  the  pericemental  membrane,  distinct 
from  other  inflammations  of  this  tissue,  although  having  many  features 
in  common  with  them.  The  disease,  he  estimates,  is  essentially  one 
of  the  peiidental  membrane  rather  than  of  the  alveolus,  although  the 
destruction  of  these  two  structures  is  so  nearly  synchronous  that  it  is 
difficult  to  say  which  has  gone  first. 

In  1886  Dr.  W.  J.  Reese  read  a  paper  before  the  Louisiana  State 
Dental  Association  on  "Uremia  and  its  Efi^ect  on  the  Teeth, "^  in  which 
the  chemical,  physiological,  and  pathological  relations  of  uric  acid  to  the 
general  nutrition  were  discussed.  In  this  communication  Dr.  Reese 
expressed  the  opinion  that  the  inflammation  of  the  pericemental  mem- 
biane,  followed  by  suppuration  and  disorganization  when  in  contact  with 
the  secretions  of  the  mouth,  is  caused  by  the  deposition  of  uric  acid 
derived  from  the  blood;  that  the  disease  should  be  termed  "phagedena 
pericementi ;"  that  "  pyorrhea  alveolaris"  is  a  misnomer.  He  also  stated 
that  while  the  tophus  on  the  roots  of  the  teeth  is  the  usual  concom- 
itant of  uric  acid,  it  is  not  necessarily  so,  but  that  absorption  of  the 
pericemental  membrane  may  take  place  without  any  deposit.    Although 


*  Vierteljahresschrift  fiir  Zahnheilkunde,  1SS2;  Britiyh  Journal  of  Dental  Science, 
vol.  XXV,  p.  1.53. 

^  Diseases  of  the  Peridental  IMembrane  having  their  Beginning  at  the  Margin  of 
the  Gum,  American  System  of  Dentistrj^,  vol.  v,  p.  953. 

^  Dental  Cosmos,  vol.  xxv,  p.  550, 


468  PYORRHEA    ALVEOLA  HIS 

a  local  treatment  was  advocated,  he  stated  that  without  systemic  or 
constitutional  treatment  the  return  of  the  trouble  may  be  expected. 

Dr.  John  S.  INIarshall,  in  1891,  expressed  his  conviction  that  pyor- 
rhea has  a  constitutional  origin  and  is  closely  allied  to  the  rheumatic 
or  gouty  diathesis;  "that  the  deposition  of  the  concretions  upon  the 
roots  of  the  teeth  in  those  localities  not  easily  reached  by  the  saliva,  or 
in  which  the  presence  of  the  saliva  would  be  an  imi)ossibility,  is  due 
to  the  causes  which  produce  the  chalky  formations  found  in  the  joints 
and  fibrous  tissues  of  gouty  and  rheumatic  individuals."^ 

C.  N.  Peirce,  in  a  series  of  papers  published  during  1892-94-95,2  pre- 
sented a  number  of  clinical  and  pathological  facts  which  in  their  totality 
it  was  believed  established  a  kinship  between  pyorrhea  alveolaris  or 
hematogenic  calcic  pericementitis  and  the  constitutional  state  familiarly 
known  as  the  gouty  or  uric  acid  diathesis. 

Recent  literature  by  American  writers  has  dealt  largely  with  the 
problem  of  the  etiology  of  the  disease  in  question  and  has  been  princi- 
pally concerned  in  determining  whether  it  is  of  constitutional  origin  or 
of  local  origin,  or  of  both.  Of  the  more  important  recent  writings  on 
the  subject  may  be  mentioned  those  of  Drs.  E.  T.  Darby,  H.  H.  Bur- 
chard,  G.  V.  Black,  E.  S.  Talbot,  M.  L.  Rhein,  E.  C.  Kirk,  James 
Truman,  Junius  E.  Cravens,  Louis  Jack,  R.  R.  Andrews,  and  R. 
Ottolengui. 

Terminology. — Xo  disease  in  the  whole  domain  of  surgery  has  received 
so  many  and  such  diverse  names  as  the  one  under  consideration.  Each 
succeeding  title  was  an  attempt  at  the  production  of  a  comprehensive 
descripti^'e  designation  of  the  disease,  but  when  it  is  recognized  that 
the  essential  nature  of  the  pathological  processes  involved  is,  even 
now,  not  fully  made  out,  it  is  evident  that  the  many  names  simply 
represent  as  many  diverse  views  and  can  therefore  have  no  permanency, 
nor  do  they,  indeed,  deserve  any. 

The  following  is  a  fairly  complete  list  of  the  synonyms  of  the  dis- 
order: Suppuration  conjointe,  pyorrhee  inter-alveolo-dentaire,  gingi- 
vitis expulsiva,  osteo-periostite-alveolo-dentaire,  pyorrhea  alveolo, 
cemento-periostitis,  infectioso-alveolitis,  pyorrhea  alveolaris,  calcic 
inflammation,  phagedenic  pericementitis,  Riggs'  disease,  interstitial 
gingivitis,  hematogenic  calcic  pericementitis,  blennorrhea  alveolaris, 
gouty  pericementitis. 

It  should  be  noted  that  pyorrhea  alveolaris  (flowing  of  pus 
from  the  alveolus)  is  a  generic  term  carelessl}'  used  to  designate  a 

1  The  Rheumatic  and  Gouty  Diathesis,  with  its  Manifestations  in  the   Peridental 
Membrane,  Transactions  American  Medical  Association,  1S91. 
^  International  Dental  Journal,  vols,  xiii,  xv,  and  xvi. 


GENERAL  CONSIDERATIONS  4G9 

group  of  disorders  all  of  which  result  in  loss  of  the  teeth  by  destruc- 
tion of  their  retentive  tissues;  also,  that  this  loss  may  and  often 
does  occur  without  the  obvious  production  of  pus  as  an  attendant 
symptom.  The  term  pyorrhea  alveolaris  is,  therefore,  inaccurate  as 
descriptive  of  the  disease  and  unscientific  except  as  it  is  indicative 
of  a  symptom  common  to  several  disorders;  but,  inasmuch  as  the  desig- 
nation is  in  common  and  general  use,  and  still  further  because  the 
etiology  of  the  several  gingival  disorders  so  described  still  remains  to 
be  scientifically  demonstrated,  it  will  be  more  convenient  to  retain 
"pyorrhea  alveolaris"  as  a  general  designation  until  a  more  accurate 
terminology  based  upon  the  known  etiology  and  pathology  of  these 
destructive  inflammatory  alveolar  disorders  becomes  possible  as  the 
result  of  further  study  and  investigation.  It  should,  therefore,  be  under- 
stood that  the  term  pyorrhea  alveolaris  is  used  throughout  this  chapter 
in  its  general  sense  as  applied  to  the  group  of  disorders  having  the 
clinical  characteristics  specified  under  "Definition"  in  the  opening 
paragraph  of  this  chapter. 

General  Considerations. — One  fact  is  clearly  evident  in  all  forms  of 
pyorrhea  alveolaris,  viz.,  that  it  is  an  inflammatory  disorder.  It  may 
be  acute  and  violent,  running  a  comparatively  short  course,  or  it  may 
be  chronic  o\'er  a  long  period;  the  evidences  of  inflammatory  activity 
may  be  so  slight  as  to  escape  other  than  critical  notice,  yet  the  morbid 
process  in  its  clinical  manifestations  and  in  its  destructive  results  falls 
strictly  within  the  limitations  prescribed  by  the  modern  definitions  of 
inflammatory  action. 

Inflammation,  as  defined  by  Adami,^  is  "the  succession  of  changes 
which  constitute  the  local  effort  at  adaptation  to  the  changes  initiated 
by  actual  or  referred  injury  to  a  part;  or,  in  short,  the  local  adaptive 
changes  resulting  from  actual  or  referred  injury."  "  An}i:hing  which  causes 
local  injury  to  the  tissues  is  a  cause  for  inflammation,  be  it  a  mechani- 
cal trauma,  a  physical  insult,  as  by  heat,  cold,  or  electricity,  a  disturb- 
ance brought  about  by  altered  metabolism  and  abnormal  internal 
secretions  or  by  bacterial  or  microbic  invasion  and  gro^i:h.  This  last 
is  the  commonest  cause  of  acute  reaction,  and  differs  from  the  physical 
and  mechanical  causes  (although  not  from  metabolic  disturbances)  in 
that,  as  a  cause,  it  is  not  of  momentary  duration,  but  continued.  It  is 
not  the  mere  physical  entry  of  microbes  into  the  tissues  that  induces 
infiammation,  but  the  liberation  by  them  of  their  products  in  gro\\i;h 
or  disintegration.  And  so  long  as  those  products  are  being  liberated, 
for  so  long  is  the  cause  in  action.    It  differs  from  the  metabolic  causes 

*  Principles  of  Pathologj-,  vol.  i,  p.  377. 


470  PYORRHEA   ALVEOLARIS 

in  that  tlie  latter  iufluce  tissue  irritation  of  a  milder  ^rade,  and  so  do 
not  induce  acute  but  rather  chronic  reactions." 

Viewed  as  an  inflammatory  process  we  ha\e,  then,  in  the  study  of 
pyorrhea  to  regard  its  clinical  or  objective  phenomena  as  reactions  of 
the  retentive  tissues  of  the  teeth  toward  injuries  inflicted  by  mechanical 
trauma,  physical  irritants,  altered  metabolism,  the  toxic  effects  of 
altered  secretions,  or  by  the  toxic  products  of  microbic  or  bacterial 
invasion.  Any  of  these  agencies,  severally  or  collectively,  may  induce 
such  changes  in  the  retentive  structures  as  will  lead  to  their  molecular 
necrosis  and  the  ultimate  exfoliation  of  the  teeth,  the  process  consti- 
tuting comprehensively  what  we  know  as  pyorrhea  alveolaris. 

Pyorrhea  alveolaris  is  a  condition  of  disease  as  opposed  to  health 
of  the  tissues  concerned  in  the  fixation  or  retention  of  the  teeth  in  the 
alveolar  borders.  It  is  a  disturbance  of  the  normal  health  of  these 
tissues. 

The  condition  which  w^e  speak  of  as  health  may  be  defined  in  its 
ideal  sense  as  that  condition  or  state  which  is  the  resultant  of  the  har- 
monious concurrent  or  interaction  of  all  those  factors  necessary  to  the 
normal  functioning  of  a  tissue  or  organism,  or,  shortly,  health  is  a  state 
of  metabolic  or  physiological  equilibrium.  Any  definition  of  health  as 
applied  to  an  organism  or  to  a  tissue  must  necessarily  be  imperfect  in 
that  it  cannot,  in  the  nature  of  the  case,  be  absolute,  for  the  reason  that 
the  functioning  of  a  tissue  or  its  cells,  as  well  as  of  the  entire  organism, 
is  dominated  by  the  factor  of  vitality  or  life,  a  phenomenon  which  in 
the  present  state  of  human  knowledge  eludes  definition.  As  a  meta- 
physical formula  the  working  definition  of  life  proposed  by  Mr.  Herbert 
Spencer  affords  assistance  in  arriving  at  a  conception  of  the  meaning 
of  that  ideal  state  of  physiological  functioning  which  we  speak  of  as 
health.  Spencer  defines  life  as  "  the  continuous  adaptation  of  internal 
relations  to  external  relations."  It  will  be  seen  that  this  conception 
includes,  as  all  attempts  at  the  definition  of  vital  action  must  include, 
a  recognition  of  the  variability  of  vitality.  Health,  then,  which  is  a 
condition  of  life  dependent  upon  physiological  balance  or  harmony  of 
metabolic  activity  (internal  conditions)  in  relation  to  environment 
(external  conditions),  can  never  be  regarded  as  a  condition  or  state 
of  stability,  but  rather  as  a  condition  of  continuous  variability.  The 
metabolic  equilibrium  of  health  is  therefore  to  be  understood  not  as 
a  fixed,  but  rather  as  an  unstable  or  moving  equilibrium. 

The  equilibrium  of  health  finds  certain  analogies  in  that  of  the  l)icycle 
in  action.  The  energy  of  the  rider  imparted  to  the  mechanism  causes  it 
to  maintain  its  balance  and  to  advance  along  a  course  which  approaches 


RTIOLOflY  471 

a  straigiit  line,  this  ai)i)r()acli  being  directly  ])n)i)()rti(>iiate  to  the  energy 
whieli  the  machine  receives.  If  the  energy  falls  below  that  required  to 
maintain  equilibrium,  the  machine  drops  to  the  ground.  External 
agencies,  such  as  inequalities  in  the  road  bed,  obstructions  to  the  smooth 
revolution  of  the  wheels,  deviations  of  the  course  involving  ascent  of 
surface  inclines,  high  winds,  these  or  any  of  the  numerous  environing 
conditions  which  may  beset  the  cyclist,  demand  recurrent  accesses  of 
energ>'  in  order  to  maintain  equilibrium  of  the  machine  and  propel  it 
upon  its  course.  Or  if,  from  fatigue  or  other  internal  causes,  the  cyclist 
becomes  incapable  of  delivering  to  his  wheel  the  necessary  potential, 
then  in  that  case  also  the  machine  falls  to  the  ground. 

The  study  of  disease  action  as  it  is  expressed  in  pyorrheal  conditions 
of  the  retentive  tissues  of  the  teeth  is  a  study  of  the  adaptive  reactions 
of  these  tissues  to  those  agencies  which  tend  to  destroy  their  normal 
physiological  equilibrium,  the  phenomena  attending  the  effort  of  the 
forces  of  the  tissues  to  oppose  injuries,  be  they  mechanical  trauma, 
physical  or  chemical. 

It  should  be  clearly  understood  that  no  sharp  dividing  line  can  be 
drawn  between  the  ideal  state  which  we  call  health  and  those  departures 
from  it  which  we  call  disease.  No  two  individuals  are  alike  in  any 
respect,  for  which  reason  the  standards  of  physiological  equilibrium, 
or  of  health,  differ  as  individuals  differ.  Nor  in  the  same  individual 
are  the  physiological  activities  continuously  in  normal  equiHbrium. 
Variations  from  the  normal  brought  about  by  the  play  of  environing 
conditions  are  constantly  producing  departures  from  normal  states  as 
a  necessary  result  of  the  process  of  living.  These  departures  from  nor- 
mality vary  by  insensible  degrees  from  little  to  greater,  so  that  it  is 
impossible  to  draw  a  sharp  Hue  of  demarcation  and  define  at  what 
point  we  cease  to  deal  with  the  physiological  state  and  are  confronted 
with  the  pathological.  This  general  fact  applies  not  only  to  the  organ- 
ism as  a  whole,  but  to  its  component  tissues  as  well,  hence  in  the  study 
of  the  group  of  gingival  disorders  here  considered  as  pyorrhea  alveolaris 
we  are  confronted  not  only  with  a  variety  of  lesions,  but  an  infinite 
gradation  in  intensity  of  the  phenomena  involved. 


ETIOLOGY 

The  study  of  pathological  lesions  must  have  its  basis  in  a  knowledge 
of  the  anatomical  structure  of  the  tissues  involved,  hence  an  under- 
standing of  the  nature  of  the  destructive  processes  which  produce 


472  pyORRIIKA    ALVEOLARIS 

necrosis  of  the  retentive  tissues  of  the  teeth,  and  their  final  exfohation 
ran  only  be  intellio;ently  arrived  at  after  a  comprehension  of  the  strncture 
and  function  of  the  retentive  tissues  of  the  teeth  has  been  acquired. 

Broadly  speaking,  the  tissues  concerned  in  the  inflammatory  processes 
under  consideration,  and  collectively  refct-red  to  as  the  retentive  tissues 
of  the  teeth,  are  the  bony  alveolar  structures  with  their  overlying  gum 
tissues  and  the  ligamentous  tissue  by  which  the  teeth  are  attached  to 
their  alveoli,  known  as  the  pericemental  or  peridental  membrane.  These 
with  their  vascular  and  nervous  supply  are  all  involved  in  the  various 
pyorrheal  affections,  while  in  certain  aspects  of  the  disorder  a  group 
of  peculiar  structures  embedded  in  the  pericementum,  probably  cellular 
renmants  of  the  embryonal  structure  known  as  the  epithelial  sheath 
of  Hertwig,  described  by  G.  V.  Black  as  lymphatic  glands/  play  a  most 
important  part.^ 

External  Factors. — As  a  Avhole,  the  teeth  and  their  associated  tissues 
are  fixed  in  an  environment  which  is  the  source  of  a  variety  of  irritative 
factors,  many  of  which  are  capable  of  exerting  harmful  influences  and, 
among  other  injurious  results,  of  giving  rise  to  the  destructive  phenomena 
of  pyorrhea  alveolaris.  Since  Antoni  van  Leeuwenhoek,  the  linen- 
draper  of  Amsterdam,  in  1683,  announced  to  the  Royal  Society  of 
London  his  discovery  of  "animalculse,"  which  he  had  found  in  the 
"materia  alba,"  or  white  deposit  scraped  from  the  surfaces  of  his  own 
teeth,  the  investigation  of  the  bacterial  forms  found  in  the  human 
mouth  has  progressed  until  at  the  present  time  it  is  a  well-established 
fact  that  the  human  mouth  is  the  breeding  ground  or  incubator  for 
an  extensive  variety  and  infinite  number  of  bacterial  forms,  many  of 
which  are  the  known  exciters  of  disease  action  both  locally  in  the  mouth 
itself  and  in  the  more  remote  organs  and  tissues  of  the  body. 

No  human  mouth  is  ever  free  from  bacterial  contamination  at  any 
time  from  birth  to  death,  and  no  method  has  as  yet  been  devised  by 
which  complete  sterilization  of  the  oral  cavity  may  be  safely  accomplished . 
Nevertheless,  very  many  mouths  are  free  from  any  evidence  of  bacterial 
invasion  and  consequent  inflammatory  reaction  of  the  tissues,  notwith- 
standing the  fact  that  even  in  such  mouths  the  presence  of  pathogenic 
bacteria  may  be  abundantly  demonstrated.  Infection  of  the  oral  tissues 
in  such  cases  is  prevented  by  the  internal  resistive  powers  of  the  dental 
and  oral  tissues,  as  infection  of  the  other  tissues  of  the  healthy  body  is 

*  A  Study  of  the  Histological  Characters  of  the  Poriosteiiin  and  Peridental  Mem- 
brane, Chicago,  1887,  p.  90.  The  Fibers  and  Glands  of  the  Peridental  Membrane, 
Dental  Cosmos,  1899,  vol.  xh,  p.  101.  . 

•^  For  a  detailed  description  of  the  retentive  structures  of  the  teeth  tlu^  n^ider  is 
referred  to  i)p.  94  to  115  of  Chapter  II. 


ETIOLOGY  473 

prevented  by  the  adaptive  agencies  of  the  vital  mechanism.  The  sum 
total  of  the  resistive  forces  against  the  invasion  of  pathogenic  bacterial 
elements  is  termed  immunity,  a  state  which  to  a  large  degree  is  one  of 
the  conditions  of  normal  health,  in  which  instance  it  is  designated  as 
natural  immunity,  or,  within  certain  limits,  the  condition  may  be 
artificially  produced,  and  it  is  then  designated  as  acquired  immunity. 

It  will  be  seen  from  the  foregoing  that  bacterial  invasion  of  the 
tissues  and  consequent  inflammatory  reaction  in  them  depends  upon  the 
o\erpowering  of  the  internal  resistive  forces  of  the  tissues  by  patho- 
genic bacteria  endowed  with  a  disease-producing  potential  of  relatively 
higher  intensity  than  that  of  the  resistive  power  of  the  tissues.  Wherever 
bacterial  invasion  and  consequent  inflammatory  reaction  in  the  tissue 
results,  it  means  that  the  defensi^•e  powers  of  the  tissue  have  been  over- 
come by  the  invading  organism,  the  equilibrium  of  tissue  health  has  been 
destroyed,  and  a  condition  of  disease  has  been  established. 

The  causes  of  pyorrheal  inflammation  are  rarely,  if  ever,  simple  in 
character  in  the  sense  that  they  are  the  direct  and  unaided  effects  of 
specific  infection  in  a  normally  healthy  tissue.  Various  contributory 
or  predisposing  factors  are  usually  concerned  in  the  production  of  these 
gingi\'al  and  alveolar  inflammations.  The  factors  which  contribute  to 
the  bacterial  invasion  of  the  gingival  tissues  may  be  broadly  classified 
as  external  and  internal. 

Among  external  causes  may  be  included  mechanical  injury  to  the 
tissues  involved.  Any  agencies  which  injuie  the  gingival  tissues  to  the 
extent  of  creating  in  them  a  traumatic  lesion  may  serve  as  a  predis- 
posing cause  of  pyorrhea  alveolaris.  Injury  to  the  tissues,  depending 
upon  its  degree  and  seriousness,  will  produce  either  cell  death  with  total 
loss  of  resistance,  or  if  not  cell  death,  then  disturbance  of  cell  function, 
with  greatly  diminished  resistance  to  bacterial  invasion. 

Injudicious  application  of  ligatures  or  clamps  in  adjusting  the  rubber 
dam,  similar  maltreatment  of  the  pericemental  membrane  at  its  cervical 
attachment  by  the  improper  application  of  band  and  other  forms  of 
matrices,  and,  above  all,  the  physical  insult  to  the  pericementum  result- 
ing from  an  unskilfully  fitted  artificial  crown,  especially  of  the  banded 
t\'pe,  are  fruitful  sources  of  traumatic  injury  which  are  definitely  known 
to  be  predisposing  causes  of  pyorrhea  ah'eolaris. 

Tartar  as  a  Predisposing  Cause. — Among  the  traumatic  predisposing 
causes  of  pyorrhea  alveolaris,  none  is  so  frequent  or  so  generally  notice- 
able as  the  injury  to  the  retentive  tissues  of  the  teeth  produced  by 
accumulation  of  salivary  calculus,  or  tartar.  Salivary  calculus  is  here 
classified  as  a  traumatic  irritant  predisposing  to  pj'orrhea  alveolaris. 


474  PYORRHEA    ALVEOLARIS 

for  the  reason  that  tlie  ciicroachnioiit  of  <j:ro\vin<^  accumulations  of  tartar 
is  not  alone  sudicient  to  account  for  the  inllaiiunatory  reaction  which 
accompanies  it,  and  further,  because  the  pus  production  associated  with 
this  form  of  pyorrhea  is  necessarily  a  result  of  bacterial  infection.  The 
exact  nature  of  the  process  of  tartar  formation  has  not  as  yet  been  made 
out  with  definite  clearness.  It  is  known  in  general  that  salivary  calculus 
or  tartar  is  composed  of  calcium  phosphate  and  carbonate  with  occa- 
sionally other  allied  salts  formed  into  a  concretion  by  the  mucinous 
elements  of  the  saliva,  and  that  it  contains  entangled  in  its  structure 
the  bodies  of  a  variety  of  bacterial  forms.  The  earthy  salts  which 
enter  into  the  composition  of  salivary  calculus  are  derived  from  the 
sali\-a,  where,  under  normal  conditions  of  health,  they  are  retained  in 
solution,  but  in  certain  unknown  nutritional  changes  which  bring  about 
alterations  in  the  composition  of  the  mixed  saliva,  a  portion  of  the 
dissolved  calcium  salts  undergoes  precipitation  upon  surfaces  of  the 
teeth  protected  from  the  friction  of  the  tongue,  lips,  and  cheek  tissues, 
these  deposits  undergoing  an  incremental  growth  until  in  some  instances 
they  attain  a  relatively  enormous  size. 

Deposits  of  tartar  upon  the  teeth  present  a  large  variety  of  forms 
and  marked  differences  in  position  and  physical  characteristics,  but 
whenever  the  deposit  impinges  upon  the  retentive  tissues  of  the  teeth 
it  acts  as  a  traumatic  irritant,  which  interferes  with  the  nutrition  of  the 
soft  tissues,  decreasing  their  normal  resistive  power,  and  by  so  doing 
renders  them  susceptible  to  invasion  by  pathogenic  organisms,  thus 
setting  up  inflammatory  reactions,  among  which  are  certain  forms  of 
pyorrhea  alveolaris.  There  is  nothing  in  the  composition  of  salivary 
tartar,  as  such,  that  can  cause  chemical  irritation.  Its  action  is  dis- 
tinctly and  simply  mechanical  or  traumatic,  and  as  a  causative  factor 
in  the  production  of  marginal  inflammation  it  must  therefore  be  classed 
as  among  the  predisposing  causes.  The  exciting  or  immediate  cause  of 
the  inflammatory  reaction  is  bacterial  infection  of  the  tissue  injured  by 
the  tartar  deposit. 

Deposits  of  tartar  are  classified,  with  respect  to  their  origin,  as  saJimn/ 
calculus  and  as  scrumal  or  sanguinary  calculus,  according  as  the  deposit 
has  been  derived  from  the  saliva  or  from  the  blood  plasma  respectively. 

While  it  has  been  definitely  determined  that  deposits  of  calculus 
occur  upon  the  roots  of  teeth  in  which  the  possibility  of  access  of  saliva 
has  been  excluded,  it  has  not  by  any  means  been  clearly  shown  that  the 
thin  scaly  deposits  of  tartar  found  upon  the  roots  of  teeth  in  cases 
of  pyorrhea  alveolaris  nor  the  thin  scale-like  ring  of  tartar  found 
encircling  the  necks  of  teeth  below  the  gingival  margin  in  similar  cases, 


ETIOLOGY 


475 


owe  their  origin  to  the  blood  plasma  and  are,  therefore,  properly 
designated  serumal  tartar,  as  such  deposits  are  ordinarily  classed,  for 
the  reason  that  in  both  these  instances  there  is  more  or  less  free  access 
of  saliva  to  the  region  of  the  deposit,  and  no  tartar  deposit  can  with 
accuracy  be  described  as  serumal  tartar  unless  absolute  exclusion  of 
saliva  from  the  region  of  the  deposit  is  demonstrable. 


rrn    535 


Fk;.  52G 


S.LC 


A,   maxillary   sinus;     B,   duct    of   Steno;    C, 
parotid  calculus;   E,  submaxillary  gland. 


C,  calculus;    S.L.C.,  sublingual  cavity; 
S.L.G.L.,  sublingual  gland. 


The  mere  physical  differences  observed  in  tartar  deposits  are  not 
in  themselves  sufficient  to  definitely  determine  either  the  salivary  or 
the  blood  origin  of  the  deposit  respectively.  Differences  in  the  physical 
characteristics  of  tartar  deposits  are  due,  among  other  things,  to  varia- 
tions in  chemical  composition  and  to  the  rate  of  growth  or  formation 
of  the  deposits,  and  these  factors  are  in  their  turn  dependent  upon  the 
composition  of  the  fluids  from  which  the  deposits  or  precipitation  of 
earthy  salts  takes  place,  while  the  composition  of  these  fluids,  finally, 
is  dependent  upon  the  nutritional  state  of  the  individual  upon  whose 
teeth  the  deposits  are  formed. 

In  certain  individuals  the  accumulation  of  tartar  as  a  deposit  from 
the  saliva  is  constant  and  relatively  rapid.  In  such  cases  the  accumu- 
lation is  greatest  upon  tooth  surfaces  which  face  the  orifices  of  the  ducts 
of  the  parotids,  the  so-called  ducts  of  Steno,  and  upon  the  lingual 


476 


PYORRHEA  ALVEOLARIS 


Fir..   537 


surfaces  of  the  lower  incisors,  Avhicli  are  opposite  tiie  orifices  of  Wharton's 
ducts  (Fifjs.  5;-5o  and  5o()).  In  tiiese  localities  precipitation  of  salivary 
tartar  occurs  most  frequently,  and  in  many  instances  the  deposits  grow 
to  enormous  size  (Figs.  537  and  53S).     That  the  deposit  is  salivary  m 

its  origin  is  shown  by  the  commonly  ob- 
sen^ed  fact  that  it  will  take  place  upon 
an  artificial  denture  as  readily  as  upon 
the  necks  of  the  natural  teeth  (Fig.  539). 
The  salivar.>"  deposit  may  be  small  in 
amount  and  relatively  slo\v  in  accumu- 
lating, or  it  may,  on  the  contrary,  be  large 
in  amount  and  accumulate  rapidly;  and 
there  also  appears  to  be  a  fairly  definite 
correspondence  between   the  density  and 


Fig.    538 


0> 

i^i  M 

^pppi^'  ^F^S^'1 

^^S^^   . 

Specimens  of   parotid  tartar;    artu.<»l  size. 
Fig.     539 


Partial  denture  elasped  to  first  and  second  molar.s,  which  have  been  lost  b.v  deposition  of 

jKirotid  tartar. 


ETIOLOGY 

Fig.  540 


477 


Fig.   541 


Fig.  542 


478 


ryoRlillEA   ALVEOLA  HIS 


liardiK'ss  of  the  deposit  and  its  rate  of  formation,  the  density  l)eing 
in  inverse  ratio  to  the  rapidity  of  its  formation.    Figs.  540,  541,  542, 


Fig.  54a 


Ftg.  544 


Fig.   545 


543,  544,  and  545  sliow  various  commonly  observed  forms  of  salivarN' 
tartar  deposition.     Another  important  factor  is,   howe\ei,  concerned 


ETIOLOCY  479 

in  tartar  formation,  one  which  has  much  to  do  with  its  physical 
characteristics  and  incidentally  with  its  rate  of  formation,  and  that 
is  the  relative  quantity  of  mucin  or  other  colloids  in  the  medium 
from  which  the  tartar  is  precipitated. 

Nature  of  Tartar  Composition. — In  1858  Mr.  Rainey,  of  London,  made 
the  important  discovery*  that  when  certain  earthy  salts  are  precipitated 
in  a  medium  containing  a  colloidal  substance  in  solution,  the  resulting 
precipitate  was  profoundly  modified  in  the  form  of  its  ultimate  particles 
V/hich  instead  of  being  crystalline  in  character  were  in  the  form  of  minute 
spheroidal  masses,  and  that  as  the  precipitation  progressed  the  sphe- 
roidal masses  increased  in  diameter  so  that  adjoining  masses  grew  into 
contact,  and,  by  accretion  of  new  material,  they  coalesced  until  finally 
the  coalescence  of  a  large  number  of  individual  spherules  gave  rise 
to  the  formation  of  mulberry-like  masses.  Mr.  Rainey's  experiments 
were  made  wdth  gum  arable  as  the  colloidal  material  in  the  menstruum 
from  which  the  precipitation  of  earthy  material  was  made,  and  micro- 
scopic examination  of  the  spheroidal  concretions  thus  produced  showed 
a  laminated  or  onion-like  structure  quite  analogous  to  that  found  in  the 
shells  of  hen's  or  bird's  eggs,  the  shells  of  molluscs,'  calcareous  concre- 
tions in  the  urine  of  the  horse,  etc.  Contemporaneously  with  Rainey's 
investigations,  Professor  Harting,^  of  Utrecht,  pursued  the  same  line  of 
inquiry,  and  not  only  confirmed  the  observations  of  Rainey,  but  greatly 
extended  his  results  by  showing  that  with  animal  colloids,  such  as  egg 
albumin,  blood  serum,  or  a  solution  of  gelatin,  a  much  greater  variety 
of  forms  may  be  produced,  many  of  them  closely  resembling  concretions 
only  found  in  the  animal  body.  Professor  Harting  brought  out  the 
further  fact  that  the  resistance  of  these  spheroidal  concretions  to  the 
solvent  action  of  acids  was  greater  than  that  of  the  precipitates  formed 
from  the  same  material  in  the  absence  of  colloids,  and  that  after  treat- 
ment by  acids  until  all  visible  particles  of  calcareous  matter  were  dis- 
solved out  there  remained  a  basic  substance  or  matrix  upon  which, 
although  it  still  retained  its  original  form,  the  acid  apparently  had  no 
further  action,  and  to  this  residue  of  insoluble  material  he  gave  the 
name  "calcoglobuHn;"  he  also  made  the  further  important  observa- 
tion that  when  various  coloring  matters,  such  as  madder,  logwood, 

^  See  his  treatise,  On  the  Mode  of  Formation  of  the  Shells  of  Animals,  of  Bone, 
and  of  Several  other  Structures  by  a  Process  of  Molecular  Coalescence  Demonstrable 
in  Certain  Artificially  Formed  Products,  1858,  and  his  Further  Experiments  and 
Observations,  in  Quarterly  Journal  of  Microscopical  Science,  1861,  n.  s.,  vol,  i, 
p.  23. 

2  See  Professor  Harting'a  Recherches  de  Morphologic  synthetique  sur  la  pro- 
duction artificielle  de  quelques  Formations  Calcaires  Inorganiques,  publiees  par 
I'Academie  Royale  Neerlandaise  des  Sciences,  Amsterdam,  1872,  and  Quarterly 
Journal  of  Microscopical  Science,  vol.  xii,  p.  118. 


480  PYOIilill/iA    ALVEOLAIilS 

uv  carmiii,  were  added  to  the  solution  in  which  the  precipitation  was 
taking  })lace  the  concretions  took  on  the  hue  of  the  dye  employed,  i.  c, 
that  they  were  readily  susceptible  of  pigmentation.  The  same  line  of 
inquiry  was  confirmed  and  further  carried  out  by  Dr.  W.  M.  Ord  ^  with 
reference  to  the  formation  of  urinary  and  other  calculi. 

The  data  derived  from  the  researches  of  Rainey,  Harting,  and  Ord 
have  ser^'ed  to  explain  the  chemical  principles  involved  not  only  in 
the  various  phenomena  of  normal  calcification  of  the  several  hard  or 
calcified  tissues  of  the  animal  body,  but  also  of  the  numerous  patho- 
logical concretions  found  associated  with  disease  processes,  such  as 
vesical,  renal,  and  biliary  calculi,  the  calcification  of  the  debris  of 
suppurative  processes  in  various  tissues  and  organs,  and  the  calculous 
deposits  upon  the  teeth.  The  essential  factor  in  all  of  these  processes 
is  the  precipitation  of  a  relatively  insoluble  earthy  substance  in  a 
medium  containing  colloid  material,  such  as  protoplasm,  albumin, 
mucin,  casein,  and  allied  organic  substances,  which  unites  with  the 
inorganic  element  to  form  compounds  having  the  physical  character- 
istics of  calcoglobulin,  and  likewise  its  habit  of  forming  spheroidal 
masses  that  grow  by  accretion  and  coalescence  into  irregular  mulberry- 
like concretions. 

The  mixed  saliva  contains  a  variable  amount  of  calcium  phosphate 
in  solution,  but  the  exact  nature  of  the  dissolved  phosphate  has  not  been 
definitely  determined.  It  is,  however,  known  that  tricalcic  phosphate, 
Ca3(P04)2,  is  soluble  in  nearly  all  acids  and  is  soluble  even  in  carbonic 
acid,  a  fact  determined  by  the  English  chemist,  W.  H.  Pepys,  Jr.,  as 
early  as  1803.^ 

As  the  saliva  contains  carbon  dioxid  in  solution,  it  has  been  assumed, 
with  some  justification,  that  the  escape  of  the  carbon  dioxid  which  w'as 
the  solvent  of  the  calcium  carbonate  and  tricalcic  phosphate,  causes  a 
precipitation  of  those  salts  in  the  presence  of  the  colloid  mucin,  in 
combination  with  which  it  deposits  as  tartar  upon  the  teeth.  While 
the  foregoing  may  serve  as  an  explanation  of  one  method  of  salivary 
tartar  formation,  an  almost  unlimited  variety  of  conditions  are  prob- 
able which  mvohe  the  fundamental  principle  of  precipitatif)n  of 
tricalcic  phosphate  from  solution,  and  when  this  precipitation  takes 
place  in  any  colloidal  medium  the  result  is  a  calcic  concretion  modi- 
fied in  its  physical  characteristics  by  the  conditions  under  which  the 
precipitation  and  concretion  occurred. 

1  On  the  Influence  of  Colloids  upon  Crystalline  Forms  and  Cohesion,  London, 
1879. 

2  The  Natural  History  of  Diseases  of  the  Human  Teeth,  In-  Joseph  Fox,  London, 
1803,  p.  94. 


KTIOIAHIY  4S1 

II.  II.  Biirclianl'  propo-scd  an  explanation  for  tlie  formation  of 
salivary  tartar  deserving  of  consideration,  \\z.,  that  inasmuch  as 
fermentative  processes  in  the  oral  cavity  give  rise  to  acids,  and  par- 
ticularly lactic  acid,  these  acids  cause  precipitation  of  the  mucin  of  the 
sali\"a  as  a  coagulum  which  entangles  in  its  structure  calcic  phosphate 
and  carbonate,  and  this  mass  by  gradual  condensation  increases 
in  density  to  the  extent  of  forming  the  coherent  deposit  known  as 
tartar. 

It  is  also  known  that  in  many  individuals  in  whose  mouths  proteid 
substances  are  undergoing  decomposition  the  exhaled  breath  contains 
appreciable  quantities  of  ammonia  which  may  be  recognized  by 
Xessler's  reaction  or  by  the  murexid  test.  It  is  further  kno\^ii  that 
ammonia  will  cause  a  precipitation  of  calcium  phosphate  from  its  acid 
solutions,  as  calcium  ammonium  phosphate,  or  when  magnesium  is 
present  ammonium  magnesium  phosphate,  so-called  triple  phosphate, 
is  also  precipitated,  and  this  latter  salt  has  been  identified  as  one  of 
the  constituents  of  certain  varieties  of  tartar. 

As  the  earthy  phosphatic  salts  of  the  saliva  must  in  the  nature  of 
the  case  be  retained  in  a  state  of  solution  in  the  saliva  by  virtue  of 
some  form  of  acid  combination  either  as  simpl}^  dissolved  in  carbon 
dioxid  or  in  the  form  of  acid  calcic  phosphate,  a  soluble  salt,  then 
any  agency  which  would  eliminate  the  acid  element,  e.  g.,  the  escape 
by  evaporation  of  the  contained  carbonic  acid,  or  again  the  presence 
of  ammonia  in  the  breath,  or  the  introduction  of  a  basic  substance  into 
the  saliva,  would  lead  to  precipitation,  as  already  shown. 

An  interesting  example  of  the  production  of  tartar  by  neutralization 
of  the  acid  solvent  element  of  the  salivary  phosphates  is  furnished  by 
the  tartar  deposits  found  upon  the  teeth  of  the  betel-nut  chewers  of 
the  IMalay  Archipelago,  India,  and  Indo-China.  The  habit  of  betel- 
nut  chewing  is  practically  universal  among  all  classes  in  the  regions 
mentioned. 

The  masticatory  bolus  is  prepared  by  wrapping  slices  of  betel-nut, 
the  fruit  of  the  areca  palm,  in  a  leaf  of  the  piper  betel,  or  Pinang, 
a  climbing  shrub  cultivated  in  the  East  to  a  prodigious  extent 
for  the  purpose.  The  slices  of  areca  nut  are  first  sprinkled  with  a 
little  lime  to  develop  the  desired  flavor.  The  chewing  of  the  bolus 
causes  a  deep  red  staining  of  the  teeth  and  the  rapid  accumulation  of 
large,  dense  deposits  of  tartar  which  at  first  are  red,  then  finally  become 
a  dark  chestnut  brown  or  black.      The  encroachment  of  the  tartar  is 

1  See  Origin  of  Salivary  Calculus,  by  Henry  H.  Burchard,  Dental  Cosmos,  1S95, 
\o\.  xxvii,  p.  821.  Also  Varieties  of  Dental  Calculi,  by  the  same  author,  Dental 
Cosmos,  1898,  vol.  xl,  p.  1. 

31 


482  J'YOh'h'I/KA    AlAKOLAh'IS 

KiG.  540  ^i"-  •'>47 


Lower  incisor  almost  completelj'  encrusted 
with  betel  tartar. 

Fio.   548 


Lower  canine  with  thick  incrustation  of 
betel  tartar. 


Fio.  649 


Lower  bicuspid  with  extensive  deposit  of  betel  tartar.       Lower  canine  covered  with  betel  tartar. 


EriOLOdY 


483 


so  rapid  and  destructive  that  habitues  frequently  become  tootiiless  at 
twenty-five  years  of  age.    Figs.  546,  547,  548,  and  549  show  examples  of 


Fig.  550 

1  ^ 

■J^^^ 

ktouj^h^^  V^  "^^^^'^Ir^^R^' 

^^^ 

'^:;-..^\S^^P|^V-'/... 

-^^.Njt^^    "      ■  ^teto- 

■b^ 

- 

|^„.r,i 

.      >%::  '    :    SH 

^ 

F^^g 

s 

^ 

w 

f. 

Upper  and  lower  incisors  lost  from  deposit  of   betel  tartar. 


intHvidual  teeth  lost  from  betel-nut  tartar,  and  Figs.  550  and  551  the 
upper  and  lower  incisor  teeth  of  an  individual  similarly  lost,  but  which 


during  the  loosening  stage  had  been  ligatured  with  fine  brass  wire  by 
a  nati\e  dentist  as  a  temporary  support,  the  whole  group  of  incisors 
being  later  exfoliated  en  vtas.s-e.  It  is  highly  probable  that  the  use  of 
the  lime  in  coiuiection  with  the  betel-nut  furnishes  the  necessary 
basic  element  to  throw  down  the  earthy  phosphates  of  the  saliva  as 
tricalcic  phosphate  in  the  form  of  tartar,  just  as  the  ammonia  of  the 
breath  performs  an  analogous  function  in  the  precipitation  of  tricalcic 
phosphate  and  triple  phosphate  as  elements  of  tartar  formation. 

Subgingival  Tartar. — The  chemical  principles  governing  the  precipi- 
tation of  earthy  pliosphates  and  carbonates  directly  from  the  saliva  in 
the  production  of  true  salivary  tartar  govern  also  the  production  of  the 
girdle-like  concretions  that  are  f(jund  encircling  the  teeth  at  and  below 
the  anatomical  neck  and  beneath  the  gum  margin.  Deposits  of  sub- 
gingival tartar  differ  markedly  in  their  physical  characteristics  from  true 
salivary  tartar,  being  denser  in  structure,  slower  of  formation,  darker 
in  color,  and  more  firmly  adherent  to  the  tooth.  These  differences  are 
most  probal)ly  due  to  the  fact  that  they  are  dejiosited  in  a  region  rich 
in  mucin,  which  exudes  freely  from  the  mucinous  acini  embedded  in 
the  marginal  gum  tissue,  and  possibly  also  from  the  gland-like  structure 
encircling  the  alveolar  border  known  as  the  gland  of  Serres.  The 
subgingival  deposits  are  always  accompanied,  and,  indeed,  are  usually 
preceded,  by  a  marginal  catarrhal  inflammation,  which  induces  an 
exudation  of  mucus  rich  in  colloidal  material,  which  is  the  binding 
material  of  the  tartar  deposit,  giving  to  it  the  resistant  quality  and 
hardness  characteristic  of  the  deposits  found  in  these  locations.  The 
peculiar  dark  brown  or  greenish  coloration  is  deri\'ed  from  the  hemo- 
globin exuded  from  the  inflamed  marginal  gum  tissue,  which,  in  contact 
with  the  hydrogen  and  ammonium  sulphid,  which  are  the  end  products 
of  putrefactive  decomposition  of  proteids,  becomes  sulfomethemo- 
globin,  the  same  compound  which  produces  the  dirty  brown  or  greenish 
discoloration  so  often  found  at  the  necks  of  teeth  in  cases  of  marginal 
gingivitis. 

While  there  are  doubtless  a  Aariety  of  conditions  which  lead  to  pre- 
cipitation of  the  earthy  salts  of  the  sali\a  in  combination  with  the 
colloidal  mucin,  thus  producing  deposits  of  infinite  variety  in  physical 
characteristics,  the  deposits,  generally  speaking,  when  first  formed,  are 
soft  and  friable,  and  are  then  readily  removed  by  a])proj)riate  instru- 
mentation; but  they  tend  to  grow  denser  and  harder  as  condensation 
of  the  mass  in  course  of  time  proceeds,  until  in  some  instances  they 
appear  to  be  as  resistant  to  cutting  instruments  as  the  cementum  of 
the  tooth  root  to  which  thev  are  attached.     On  the  other  hand,  the 


ETIOLOCY  485 

larger  salivary  calculi  of  rapid  growtli  are  generally  friable  and  chalky 
in  texturt\  showing  a  relatively  less  amount  of  organic  colloidal  binding 
material  in  their  structure,  the  precipitation  having  occurred  in  a  saliva 
containing  a  deficiency  of  the  mucinous  element. 

The  extent  of  the  inflammatory  reaction  induced  by  the  impingement 
of  salivary  calculus  u})on  the  gingi\'al  tissues  varies  between  wide  ex- 
tremes from  a  slight  superficial  gingivitis  to  an  acti\'e,  necrotic,  suppura- 
ti\e  inflammation  which  is  a  true  pyorrhea  aheolaris.  In  cases  where 
the  resistive  forces  of  the  gingi^•al  and  alveolar  tissues  are  of  normal 
standard  the  destructi\e  process  initiated  by  the  tartar  deposit  is 
superficial  and  ulccrati\'e  in  type.  On  the  surface  of  the  tissue  imme- 
diately below  the  surface  of  contact  of  the  deposit  an  ulcerati\'e  destruc- 
tion of  the  tissue  elements  takes  place,  the  area  of  engorgement,  recog- 
nizable as  a  red  line,  is  quite  shallow,  with  normal  healthy  tissue  imme- 
diately below  it.  When  the  impinging  mass  of  tartar  is  carefully  removed 
and  the  contact  surface  tissue  is  examined,  it  will  show  a  denuded 
ulcerating  appearance  with  frequently  the  evidences  of  necrotic  tissue 
debris  and  pus  distributed  over  the  exposed  area.  If  the  tartar  deposit 
has  been  a  sufficiently  large  one,  its  surface  of  contact  with  the  soft 
tissue  wull  frequently  show  distinctive  evidences  of  pus  formation, 
the  exudate  being  of  a  characteristic  dark  greenish  or  yellowish-brown 
color.  Where  the  deposit  is  permitted  to  remain  and  to  increase  in  size, 
the  ulcerative  process  continues  until  the  retenti^•e  structures  of  the 
invoh'ed  teeth  are  completely  destroyed  and  the  teeth  are  exfoliated. 
The  characteristic  distinction  between  this  type  of  destructive  inflam- 
matory disease  of  the  retentive  tissues  of  the  teeth  due  to  deposits  of 
salivary  tartar  and  those  of  the  graver  and  more  intractable  class  of 
pyorrheal  disorders  of  the  same  structures  is  the  superficial  and  ulcerative 
character  of  the  inflammatory  lesion  in  the  former.  The  injury  caused 
by  the  impingement  of  the  tartar  deposit  has  damaged  the  subjacent 
tissue  only  upon  its  surface,  consequently  the  bacterial  invasion  of  the 
damaged  tissue  has  been  little  more  than  superficial;  the  defensive 
forces  of  the  underlying  healthy  tissue  limit  the  bacterial  invasion 
to  the  layer  of  cells  which  were  functionally  disabled  as  the  result  of 
encroachment  by  the  tartar  deposit. 

Where  the  inflammatory  process  has  not  destroyed  the  mechanical 
efficiency  of  the  attachment  of  the  tooth  to  its  alveolus,  the  disease 
condition  is  readily  curable  by  the  removal  of  its  cause. 


486  PYORRHKA   ALVKOLARIS 


TREATMENT 


The  operation  of  remo\  iiig  tartar  de])osits  is  commonly  described 
as  "scaling  the  teeth,"  and  the  instruments  employed  specifically  for 
that  piir})()se  are  designated  as  scalers. 

Instruments. — For  the  removal  of  large  concretions  of  tartar  a  few 
simple  forms  of  scalers  are  sufficient,  as  indicated  in  Chapter  IV,  Fig. 
1(J(),  but  for  the  remo\al  of  smaller  deposits,  esjiecially  those  situated 
below  the  anatomical  neck  of  the  tooth,  an  outfit  of  more  delicately 
constructed  instruments,  a  sufficient  number  of  them  having  curvatures 
of  shank  so  contrived  as  to  admit  of  ready  application  to  all  the  surfaces 
of  all  of  the  teeth,  should  form  part  of  the  armamentarium  of  every 
practitioner  who  attempts  to  effectively  perform  the  operation  of  scaling. 

Two  types  of  effective  cutting  edge  should  be  a\'ailable  in  connection 
with  the  several  forms  of  instrument  shank  comprising  the  operator's 
outfit  of  scalers,  viz.,  the  type  which  is  used  for  a  pushing  cut  and  the 
type  used  for  a  pull  or  drawing  cut.  Certain  scaler  points  may  combine 
both  possibilities:  for  example,  when  the  blade  of  the  scaler  is  turned 
to  an  exact  right  angle  with  the  shank  and  its  end  is  then  ground  squarely 
across,  it  forms  an  instrument  with  a  double  cutting  edge  that  may 
be  effectively  operated  for  eitlier  a  push  or  draw  cut  when  due  consider- 
ation is  given  to  the  angle  at  which  either  of  the  effective  cutting  edges 
is  applied  to  the  tooth  root.  Instruments  to  be  used  exclusively  for 
draw  cutting  or  scraping  should  be  given  a  slight  be^•el  in  the  direction 
toward  which  the  cutting  is  done,  while  those  which  are  to  be  operated 
with  a  pushing  force  are  most  efi'ective  when  the  ends  are  ground  square, 
although  some  operators  prefer  a  slightly  bevelled  cutting  edge  even  in 
scalers  of  the  push  cutting  type.  WhatcAcr  may  be  the  choice  as  to 
angle  of  edge,  it  is  essential  that  the  edge  be  kept  sharp  if  effecti\'e  work 
is  to  be  accomplished  with  it.  Besides  proper  curvature  of  shank  and 
character  of  working  edge,  it  is  of  paramount  importance  that  the 
working  ends  of  root  scalers  be  so  delicately  fashioned  that  they  may  be 
readily  inserted  to  the  ultimate  depth  of  pyorrheal  pockets  without 
unduly  disturbing  the  pocket  or  wounding  the  gum  tissue,  and  it  is 
equally  important  that  they  be  so  tempered  that  they  will  not  break  or 
permanently  bend  in  use.  The  necks  and  shanks  should  be  gi^•en  a  blue 
spring  temper  and  the  cutting  ends  a  light  brown  or  straw  color.  It  is 
not  necessary,  nor  is  it  desirable  that  the  points  should  be  left  full  hard, 
as  in  certain  enamel  cutting  instruments. 

Finally,  the  matter  of  handles  is  by  no  means  unimportant,  for  the 


TREATMENT 


487 


reason  that  in  the  most  difficult  and  delicate  })art  of  the  ojieration  of 
root  scaHiig  the  operator  must  be  guided  by  liis  tactile  sense  alone  in 
locating  the  deposits  and  determining  when  the  root  surface  is  smooth 
and  free  from  concretions.  For  this  reason  the  handle  of  the  instrument 
must  be  of  such  size,  weight,  and  form  as  will  interpose  the  least  possible 
barrier  to  the  accurate  transmission  of  the  tactile  impression.     The 

Fig.  ■5o2 


60 


61 


character  of  instrument  handle  is  largely  a  question  of  individual 
experience  and  experiment,  and  each  operator,  especially  those  who  to 
a  greater  or  less  extent  specialize  in  the  treatment  of  pyorrhea  cases, 
should  discover  by  careful  study  and  experimentation  for  himself  the 
type  of  scaler  handle  best  adapted  to  his  individual  use,  and  through 
which  he  can  best  receive  an  intelligible  understanding  of  the  conditions 


Fig.  553 


Fig.  554 


9  10 

Abbott's  scalers. 


7  11 

Darby-Perry  scalers. 


he  has  to  meet  in  the  removal  of  root  deposits  by  instrumentation,  and, 
above  all,  his  equipment  of  instruments  should  be  ample  to  enable  him 
to  meet  all  operative  requirements. 

A  selection  of  twenty-five  scalers  which  will  enable  the  beginner  to 
meet  ordinary  conditions  is  shown  in  Figs.  552  to  558.  The  numbering 
is  that  of  the  manufacturers'  catalogue,  which  has  been  retained  for 


4.SS 


PVOimi/I'JA    ALVEOLA  HIS 


identification.  Tliis  equipment  sliould  l)e  added  to  as  tlie  need  for 
more  specialized  forms  arises  and  after  experience  has  developed 
facilit\'  in  the  use  of  those  in  the  collection  illnstratcd. 


Harlan's  scalers 


4  5  (•)  7  S 

Toinpkin's  pyorrhea  scalers. 


For  the  preliminary  breaking  up  of  calcareous  deposits  the  writer 
has  devised  a  form  of  scaler  with  a  dentate  cutting  edge  which  serves 
a  useful  purpose  in  dislodging  the  thin  scale-like  tartar  deposits  upon 
tooth  roots  (Fig.  558).  The  dentate  edges  of  these  instruments  will 
break  up  such  a  deposit  often  when  a  smooth-edged  instrument  will 
fail  to  penetrate  it.  The  dentate  scaler  should  be  followed  by  the  use 
of  a  smooth-edged  instrument  to  remove  any  adhering  small  particles 
of  concretion  and  to  give  to  the  root  a  smooth  surface. 


Fig.  558 


Adair's  scalers. 


2  6 

Kirk's  dentate  scalers. 


Besides  the  difficulty  of  access  and  the  obscurity  of  location  which 
ordinarily  prevents  the  use  of  direct  vision  as  an  aid  in  determining  the 
position  of  calcareous  deposits  on  the  roots  of  teeth,  the  operation  of 


TREATMENT  489 

scaling  for  the  removal  of  subgingival  tartar  is  complicated  by  the  slight 
hemorrhage  incidental  to  the  operation,  and  not  infrequently  by  the 
pain  which  attends  it.  ^^arious  means  may  be  employed  to  control 
both  of  these  conditions. 

Asepsis. — It  is  as  important  here  as  in  any  other  surgical  operation 
that  the  principle  of  asepsis  should  be  applied  and  practically  utilized, 
and  while  it  is  not  possible  under  the  conditions  presented  to  secure 
a  sterile  field  of  operation,  it  is  quite  possible  to  greatly  diminish  the 
bacterial  content  of  the  mouth  and  to  largely  eliminate  the  sources  of 
infection  from  the  field  of  operation. 

Preparatory  Details. — In  undertaking  the  scaling  operation  in  a 
typical  p}'orrhea  case  it  is  assumed  that  it  is  for  a  patient  who  gives 
average  attention  to  the  details  of  the  daily  dental  toilet,  and  that  the 
teeth,  as  a  whole,  are  therefore  reasonably  free  from  fermenting  deposits 
or  putrefactive  debris.  If  the  teeth  are,  however,  not  in  a  reasonably 
clean  state,  and  show  evidences  of  carelessness  or  neglect  as  to  ordinary 
oral  cleanliness,  the  necessary  instructions  as  to  thorough  cleansing 
with  brush  and  dentrifices  should  be  given  and  the  case  dismissed  until 
a  later  sitting,  when  these  instructions  shall  have  been  carried  out. 
When  the  case  again  presents,  the  field  of  operation  should  be  pro- 
tected from  saliva  by  a  properly  adjusted  napkin,  then  dried  with 
spongoid,  cotton,  or  bibulous  paper,  followed  by  a  continuous  blast 
of  warm  air  at  about  110°  or  115°  F.,  and  painted  with  official 
tincture  of  iodin  U.  S.  P.,  which  contains  7  per  cent,  iodin.  The  gums 
and  teeth  should  be  well  stained  wdth  the  iodin,  which  cannot  be  satis- 
factorily done  in  the  presence  of  moisture,  and  as  the  whole  denture 
cannot,  under  the  circumstances,  be  dried  at  once,  the  drying  and 
coating  with  iodin  must  be  done  over  a  convenient  area  at  one  time  and 
the  operation  repeated  over  a  new  area  until  all  of  the  involved  teeth 
have  been  so  treated.  The  action  of  the  iodin  is  threefold — it  is  an 
efficient  germicide  and  antiseptic,  it  is  sHghtly  astringent,  and  in  the 
strength  prescribed  it  is  a  stimulant  to  the  vascular  supply  and  cell 
activity  of  the  disordered  tissues.  After  the  iodin  application,  all 
visible  deposits  of  salivary  tartar  should  be  removed  and  the  teeth 
polished  with  fine  pumice.  Attention  should  next  be  directed  to  the 
subgingival  deposits  and  concretions  upon  the  roots. 

Removal  of  the  Deposits. — The  operation  of  scaling  and  cleansing  the 
teeth  has  thus  far  been  considered  from  the  standpoint  of  the  denture  as 
a  whole.  It  is  now  of  vital  importance  to  the  success  of  the  operation  that 
the  operator  concentrate  his  attention  exclusively  upon  the  individual 
tooth  under  treatment,  and  that  he  devote  his  time  and  his  manipula- 


490  I'YOIiRIIKA   ALVEOLAIilS 

tiou  to  that  particular  tooth  until  he  is  coiiviiiccd  that  its  root  or  roots 
are  free  from  deposits  of  \vhate\'er  character  })efore  pr()cee(hiig  to  treat 
the  next.  The  operation  must  })e  thorough  and  the  removal  of  deposits 
complete;  the  ideal  should  be  to  remo\e  the  l(iH  particle  of  tartar,  that 
which  is  in  contact  with  the  marginal  attachment  of  the  pericementum ; 
all  those  particles  which  precede  the  last  one  are  of  relatively  minor 
importance,  for  if  the  last  one  be  allowed  to  remain,  the  whole  operation 
results  in  failure.  Patient,  persistent  thoroughness,  a  cultivated  touch, 
and  educated  skill  are  all  requisites  for  success  in  this  phase  of  the 
treatment. 

Control  of  Hemorrhage. — During  the  course  of  the  operation  often 
the  flow  of  blood  will  so  obscure  the  field  that  at  times  it  may  become 
an  annoying  interference  with  further  progress.  A  certain  amount  of 
hemorrhage  in  the  early  stages  of  the  work  may  be  deemed  beneficial, 
as  it  relieves  the  engorgement  of  the  gingival  tissues  usually  present  in 
these  cases,  for  which  reason  the  flow  of  blood  may  for  a  time  be  properly 
encouraged  by  a  stream  of  warm  water  slightly  above  body  temperature. 
Ordinarily  the  flow  of  blood  will  decrease  when  the  tissues  have  thus 
relieved  themselves  of  their  abnormal  engorgement,  but  if  it  persists 
to  an  annoying  extent  it  may  be  reduced  or  even  completely  arrested 
by  a  stream  of  water  as  hot  as  can  be  borne  by  the  tissues  thrown 
against  them  from  a  syringe,  or  concentrated  hydrogen  dioxid  (10 
per  cent.)  touched  to  the  pockets  or  bleeding  surface  is  an  efficient 
hemostatic.  The  hemorrhage  may  be  positively  controlled  by  an 
ajjplication  of  trichloracetic  acid  (10  per  cent.)  applied  to  the  bleeding 
surface.  Stronger  concentrations  should  not  be  used,  as  they  have  a 
destructive  action  upon  the  soft  tissues.  A  most  useful  adjunct  in  the 
treatment  of  pyorrhea  cases  for  the  control  of  oozing  of  blood  or  serum 
into  the  pocket,  for  cleansing  the  pocket  from  debris  and  rendering  it 
patulous,  so  that  from  time  to  time  a  direct  view  of  the  root  and  interior 
of  the  pocket  may  be  obtained  in  favorable  situations,  is  the  forcible 
injection  of  heated  air  under  high  pressure,  as  first  suggested  and 
advocated  by  Dr.  H.  C.  Register,  of  Philadelphia.^ 

Control  of  Pain. — The  margin  of  the  pericementum  when  irritated  and 
inflamed  by  contact  with  subgingival  tartar  is  often  exquisitely  sensi- 
tive, a  condition  which  in  nervous  patients  prevents  that  passive  sub- 
mission to  the  treatment  necessary  to  the  performance  of  so  delicate 
and  difficult  an  operation.  Under  such  circumstances,  to  relieve  pain 
and  secure  passivity  of  the  patient,  it  is  advisable  and  proper  to  induce 

^  The  Treatment  of  Dental  Lesions  by  Compressed  A\' armed  and  Dried  Air, 
H.  C.  Register,  Dental  Cosmos,  vol.  xxvii,  p.  594. 


TREATMENT  491 

local  auostlic'sia  of  the  gingi\al  and  i)t'ric'eiiK"iital  Jiiargiiis.  This  can 
usually  he  accomplish(Ml  by  means  of  the  topical  application  of  a  con- 
centrated cocain  hydrochlorid  sohition.  A  twist  of  cotton  is  saturated 
with  the  solution  and  packed  with  a  suitable  instrument  under  tiie  gum 
and  allowed  to  remain  in  situ  for  a  few  minutes.  The  region  should  be 
made  dry  pi  eviously  to  the  application,  and  it  will  then  usually  be 
found  that  the  sensitiveness  has  disappeared.  If  the  topical  application 
should  fail  to  relieve  the  hypersensitiveness,  then  resort  may  be  had  to 
a  subgingival  injection  of  a  1  per  cent,  cocain  or  2  per  cent,  novocain 
local  anesthetic  solution  in  the  same  manner  and  under  the  same  pre- 
cautions as  are  necessary  in  the  induction  of  local  anesthesia  for  tooth 
extraction.     (See  Chapter  XVIII.) 

Chemical  Aids  to  the  Scaling  Operation. — The  resistive  texture  of  sub- 
gingival tartar  deposits  and  their  firm  adherence  to  the  root  surface  has 
led  to  the  use  of  acid  solvents  as  an  aid  to  disintegrating  the  refractory 
deposits  by  chemical  means.  Dilute  sulfuric  acid  {acidum  sidphuricum 
dilutum  U.  S.  P.,  10  per  cent.  H^SOP,  or  the  official  aromatic  sulfuric 
acid  {acidum  sulphuricum  aromaticuni) ,  containing  20  per  cent,  of 
absolute  H^SO^,  has  been  highly  recommended,  especially  by  Professor 
James  Truman,  not  only  as  a  means  for  chemically  loosening  tartar 
deposits  upon  the  roots  of  teeth,  but  also  for  its  value  in  disintegrating 
the  necrotic  alveolar  margins  and  stimulating  the  subjacent  vital  tissues 
to  healthy  reparative  action. 

Strong  lactic  acid  has  been  extensively  used  for  the  same  purpose 
and  for  the  same  general  reasons;  it  has  the  advantage  of  higher  solvent 
power  for  tricalcic  phosphate,  which  it  dissolves  w^ithout  leaving  a 
residue;  sulfuric  acid,  on  the  contrary,  converts  the  tricalcic  phosphate 
into  calcium  sulfate,  setting  free  the  phosphoric  acid,  and  unless  the 
sulfuric  acid  be  sufficiently  dilute,  its  action  tends  to  be  superficial  and 
self-limiting,  owing  to  the  formation  of  a  protective  layer  of  calcium 
sulfate  upon  the  surface  of  the  tartar  nodule.  The  self-limiting  action 
of  strong  sulfuric  action  upon  dentin  is  well  shown  in  Calahan's 
method  of  root  canal  treatment 

Trichloracetic  acid  also  aids  in  the  disintegration  of  deposits  of  tartar 
on  roots  of  teeth,  but  both  trichloracetic  acid  and  lactic  acid  are 
coagulators  of  mucin,  and  their  action  upon  the  mucinous  binding 
element  of  the  tartar  deposit  tends  to  inhibit  their  otherwise  useful 
solvent  action  upon  the  earthy  mineral  constituent  of  the  tartar. 

In  a  paper  on  "A  Tartar  Solvent  Especially  Useful  in  Pyorrhea 
Work,"^  Dr.  Joseph  Head  reported  an  in^'estigation  which  he  had  made 

^  Transactions  National  Dental  Association,  1899,  p.  131. 


492  PYORRHEA   AJAEOLAR/S 

of  the  action  of  acid  aininoiiiuiii  fluorid  as  a  soKeiit  of  tartar  fleiM)sits, 
and  aiiiiouiicc(l  as  the  result  of  his  stufhes  that  a  sohition  of  the  salt  in 
question  })ossessed  the  remarkable  ])ro])erty  of  disintegrating  tartar 
deposits,  while  it  was  without  action  upon  tooth  structure.  The  prepa- 
ration of  the  inventor  is  sold  in  the  depots  under  the  proprietary  name 
of  "Tartasol."  Reports  as  to  its  efficiency  on  the  whole  suj^port  the 
claims  made  for  it,  although  a  few  cases  of  undue  escharotic  action 
from  its  use  ha\e  been  re[)orted,  and  its  application  is  generally  rejjorted 
to  be  painful.  While  any  acid  compound  of  hydrofluoric  acid  should 
be  used  with  caution  in  contact  with  living  tissues  because  of  the  well- 
known  destructi\'e  action  of  hydrofluoric  acid,  the  preparation  in 
question,  if  its  free  acid  is  sufficiently  neutralized  to  control  its  eschar- 
otic  efi'ect,  should  be  a  valuable  adjunct  to  pyorrhea!  treatment  not 
only  because  of  its  professed  action  as  a  tartar  soKent,  but  UKjre  par- 
ticularly because  of  the  well-known  germicidal  action  of  the  fluorin 
compounds  with  the  alkali  bases. 

After-treatment. — When  the  teeth  and  exposed  ro(jt  surfaces  have 
been  freed  of  all  deposits  of  extraneous  matter  of  whatever  nature  by 
appropriate  operative  means,  the  retentive  and  surrounding  tissues 
usually  require  further  treatment  to  bring  about  a  return  to  normal 
conditions.  The  pi-inciples  governing  the  treatment  relate  to  restoration 
of  disordered  circulation  in  the  involved  tissues,  reestablishment  of 
their  normal  tone,  and  the  prevention  of  reinfection,  to  accomplish 
which,  local  astringent,  stimulant,  and  antiseptic  applications  should 
be  judiciously  made;  massage  of  the  gum  tissue  may  be  employed,  and 
the  daily  use  of  an  appropriate  lotion  by  the  patient,  together  with 
the  most  scrupulous  attention  to  the  details  of  the  dental  toilet,  should 
be  insisted  upon. 

As  a  local  application  which  is  stimulant,  germicidal,  and  astringent, 
to  immediately  follow  the  conclusion  of  operative  treatment  of  the 
teeth,  the  iodoglycerol  of  Talbot  is  of  much  value.  It  consists  of  a 
solution  in  which  the  germicidal  properties  of  iodin  are  reinforced  by 
the  astringent  and  antiseptic  properties  of  zinc  iodid.  The  formula  is 
as  follows: 

Zinc  iodid 1.5  piirts 

Water 10     " 

Iodin 2.5     " 

Glycerin .  .50     " 

An  analogous  combination,  more  complicated  in  its  mode  of  prepa- 
ration but  essentially  the  same  in  therapeutic  efficiency,  although  less 
liable  to  exert  an  escharotic  effect  for  the  reason  that  it  is  not  so  con- 


TREATMENT  493 

centrated,  is  W,  J,  Youugcr's  preparation,  which  is  made  as  follows: 
Mix  equal  parts  of  No.  1,  a  saturated  aqueous  solution  of  zinc  sulfate, 
and  No.  2,  a  saturated  solution  of  iodin  in  a  solution  of  potassium  iodid, 
1  ounce;  watei,  4  ounces.  The  reaction  of  the  potassium  iodid  with 
the  zinc  sulfate  in  Younger's  formula  results  in  the  formation  of  zinc 
iodid  and  potassium  sulfate,  which  latter  salt  in  time  crystallizes  out, 
lea^'ing  a  supernatant  solution  of  zinc  iodid  and  iodin,  which  is  the 
effecti\'e  therapeutic  combination  of  the  preparation.  Either  of  these 
solutions  applied  by  means  of  an  appropriately  shaped  orange-wood 
point,  or  upon  asbestos  fiber  wrapped  around  an  aluminum  wire  appli- 
cator, will  render  the  surface  of  the  tissue  impregnable  to  bacterial 
invasion  and  destroy  infection  to  a  considerable  depth  in  the  tissue;  at 
the  same  time  the  astringent  properties  of  the  zinc  iodid  exert  a  stim- 
ulant and  supporting  effect,  restoring  tone  to  the  capillary  system.  The 
topical  application  of  these  solutions  should  not  be  repeated  oftener 
than  twice  or  three  times  per  week,  as  opportunity  should  be  given  for 
healthy  tissue  to  form,  which  too  frequently  repeated  treatment  by  such 
concentrated  solutions  of  iodin  and  zinc  iodid  would  tend  to  prevent. 
G.  V.  Black  has  recommended  the  treatment  of  pyorrheal  pockets  and 
necrotic  areas  with  the  following: 

Oil  of  cassia 1  part 

Phenol,  cryst 2     " 

Oil  of  wintergreea 3     " 

Campho-phenique  has  also  been  recommended  for  the  same  purpose. 

James  Truman  strongly  advocates  the  packing  of  pockets  with 
quinin  sulfate.  Any  mild  antiseptic,  stimulant,  and  astringent  appli- 
cation which  is  sufficiently  lasting  when  applied  to  the  tissues  in 
question  will  produce  favorable  results.  The  iodin  and  zinc  iodid 
preparations  of  Talbot  and  Younger  respectively  ha^'e,  in  the 
experience  of  the  writer,  given  more  satisfactory  results  in  the  first 
phase  of  the  local  after-treatment  of  pyorrhea  than  any  other  medica- 
ment tried. 

As  a  lotion  for  daily  use  by  the  patient  nothing  has  yielded  such 
definitely  satisfactory  results  in  the  writer's  experience  as  the  following: 

I^. — Zinci  chloridi 5j 

Aqua;  menthse  piperitae fSviij 

Sig. — Apply  to  the  gums  on  a  cotton  swab,  t.  i.  d.' 

^  Zinc  chloric!  appears  to  have  been  first  recommended  for  this  use  by  the  late 
Professor  Charles  J.  Essig,  who  also  suggested  the  use  of  dilute  sulfuric  acid  as  a 
means  for  softening  and  disintegrating  refractory  tartar  deposits  upon  tooth  roots. 
See  an  important  paper  on  Some  of  the  Causes  of  Loss  of  the  TeetJi  in  the  Adult, 
by  Charles  J.  Essig,  M.D.,  D.D.S.,  Dental  Cosmos,  1880,  vol,  xxii,  p.  130. 


494  I'YORRIIKA   ALVEOLAN/S 

The  patient  should  be  directed  to  avoid  swallowing  any  of  the  lotion, 
and  the  application  should  be  made  after  the  teeth  ha\e  been  cleansed 
by  l)rushing  following  the  regular  meals. 

The  prognosis  is  favorable  in  cases  where  the  essential  predisposing 
cause  of  the  pxorrhea  is  tartar  of  salivary  origin  or  tartar,  mucoid  and 
salivary,  girdling  the  tooth  below  the  anatomical  neck  acting  trau- 
matically. 

PYORRHEA  HAVING  A  CONSTITUTIONAL  PREDISPOSITION 

Loss  of  the  teeth  by  a  necrotic  inflammatory  process  involving  their 
retentive  structures  and  wholly  without  the  interventif)n  of  tartar 
deposits  as  a  factor  in  the  process  is  a  common  phenomenon  well 
established  by  observation  and  experience.  It  is  equally  well  estab- 
lished that  loss  of  the  teeth  in  these  cases  is  generally  associated  with 
other  objective  phenomena  indicating  aberrations  of  various  kinds 
from  the  normal  standards  of  bodily  health.  The  nutritional  fault 
may  be  so  slight  as  to  escape  casual  notice,  or  may  e\en  be  unrecognized 
by  the  patient;  or,  on  the  other  hand,  the  destructive  action  going 
on  in  the  retentive  structures  of  the  teeth  may  be  definitely  concurrent 
with  a  clearly  defined  and  well-recognized  bodily  disease.  The  asso- 
ciation of  tabes  dorsalis,  leukemia,  sx-philis,  arthritism,  diabetes  mellitus, 
various  forms  of  nephritis,  tuberculosis,  etc.,  and  the  prolonged  mal- 
nutrition often  following  typhoid,  pneumonia,  malaria,  and  other 
U'pes  of  acute  infection  are  matters  of  observation  and  record  by  both 
physicians  and  dentists.  So  also  disorders  which  have  their  origin  in 
defects  of  the  nutritional  mechanism;  the  diseases  of  metabolism,  so 
called,  are  more  or  less  constantly  associated  with  pyorrheal  disease  of 
the  dental  retentive  tissues,  especially  when  the  individuals  so  affected 
are  well  advanced  in  adult  life,  andnotinfrequently  at  an  earlier  period 
if  the  nutritional  fault  is  pronounced  and  chronic.  The  disease  may 
attack  a  single  tooth  or  several  at  one  time,  or  in  comparatively 
rare  instances  the  teeth  of  the  entire  denture  may  be  simultaneously 
involved. 

Tartar  deposits  ma\'  or  may  not  be  present,  and  if  present,  may  ha\e 
no  direct  causal  relation  to  the  destructive  inflammatory  action.  On 
the  other  hand,  certain  calcareous  deposits  found  upon  tooth  roots  of 
this  class  of  pyorrheal  cases  are  distinctly  a  result  rather  than  the 
cause  of  the  local  inflammation. 

The  tyi)e  of  pyorrhea  associated  with  constitutional  or  general 
nutritional  disorders  diffei-s  essentially  in  its  clinical  manifestations  by 


PYOHIilJKA   llAVINl}  A   CONSTITUTION Al.   I'liEDISI'OSITION      495 

reason  of  the  dopth  of  the  invasion  of  the  retentive  structures  by  tlie 
pathogenic  bacteria  which  are  the  exciters  of  the  inflammatory  process 
under  consideration.  The  locaHzed  gingivitis  and  subsequent  pyorrheal 
condition  caused  by  the  impingement  of  saHvary  tartar  upon  the 
marginal  gum  tissue  is  superficial  and  ulcerative  in  type,  while  that 
due  to  deeper  invasion  of  the  retentive  tissues  by  pathogenic  organisms 
made  possible  by  the  lowered  internal  or  vital  resistance  of  the  tissues 
from  malnutrition  or  constitutional  disease  is  characterized  by  deep 
pus-pocket  formation  or  by  the  tendency  to  periodically  form  abscesses. 
.  Numerous  investigators  ha\-e  endeavored  to  isolate  the  specific 
organism  which  it  has  been  assumed  might  be  the  exciter  of  this  destruc- 
ti\e  process,  and  while  the  search  thus  far  has  yielded  no  definite  results 
in  so  far  as  the  discovery  of  a  single  specific  organism  as  the  cause  of 
pyorrheal  infection  is  concerned,  the  evidence  thus  far  attained  points 
strongly  to  the  conclusion  that  the  organism  mainly  concerned  in  the 
causation  of  the  type  of  pyorrhea  here  under  consideration  is  the  pneu- 
mococcus,^  which  acts  as  the  initial  exciter  of  the  inflammatory  process, 
and  that  the  reaction  produced  by  that  organism  is  supplemented  by  a 
secondary  invasion  of  the  infected  region  by  the  Streptococcus  pyogenes 
and  Staphylococcus  pyogenes  aureus  and  its  congeners.  In  short,  it 
appears  to  be  a  mixed  infection  in  which  the  pneumococcus  plays 
the  role  of  leader  in  an  attack  which  is  followed  by  organisms  of 
relatively  less  virulence. 

The  predilection  of  the  peridental  membrane  to  infection  by  the 
pneumococcus  has  been  definitely  noted  and  reported  upon  by  numer- 
ous observers;  indeed,  the  periosteum  of  the  entire  mandible  has  been, 
in  several  cases,  found  to  be  the  seat  of  destructive  inflammatory 
action  set  up  by  pneumoccocal  infection  alone,  or  associated  with 
Staphylococcus  pyogenes  aureus,  and  in  cases  of  general  constitutional 
disease,  where  from  the  nutritional  interference  the  natural  defensive 
forces  of  the  tissues  are  below  their  normal  health  standard,  invasion 
of  the  pericementum  by  the  pneumococcus,  which  is  an  almost  constant 
inhabitant  of  the  oral  cavity,  is  prone  to  occur." 

The  path  of  the  infection  is  in  all  probability  along  the  network  of 
cells  described  by  Black  as  the  "glands  of  the  peridental  membrane" 
(see  page  472),  and  who  found  in  the  microscopic  examination  of  a 

^  It  is  recognized  that  reports  of  bacteriological  studies  of  pyorrheal  exudates  by 
no  means  uniformly  record  the  presence  of  the  pneumococcus.  It  is  regrettable 
that  in  many  instances  the  methods  employed  and  especially  the  composition  of  the 
culture  media  is  not  stated.  By  the  methods  stated  at  p.  611  the  practical  con- 
stancy of  the  pneumococcus  in  pyorrheal  exudates  has  been  determined. 

2  See  under  General  Considerations,  p.  469,  a  discussion  of  the  principles  involved 
in  the  relation  of  nornaal  health  status  to  defence  against  bacterial  invasion. 


496  PYORRHEA    ALVKOLARIS 

tooth  extracted  i'roin  a  patient  sutteriiifjj  from  "  pliaf^edenic  j^ericemen- 
titis"  (the  type  of  pyorrheal  iuHaniniation  here  under  consideration) 
"  that  some  of  the  lymphatics  near  the  gingi\'al  border  of  the  membrane 
were  in  a  state  of  suppuration."  This  condition  followed  the  lymph 
chains  in  the  direction  of  the  apex  of  the  root  to  a  distance  which  the 
author  says  surprised  him,  "considering  the  very  slight  signs  of  the 
disease  before  the  removal  of  the  tooth,  and  seemed  especially  confined 
to  these  cells."  He  says,  further:  "This  case  hints  quite  strongly  that 
these  lymphatics  are  the  seat  of  this  very  peculiar  affection."^  While 
further  scientific  study  of  this  phase  of  the  matter  is  needed  to  thoroughly 
classify  the  question  of  the  part  played  by  these  structures  described 
by  Black  as  glands  of  the  peridental  membrane,  as  the  pathways  of 
bacterial  invasion  in  pyorrheal  disease,  clinical  observation  tends 
to  amply  confirm  the  observations  made  on  the  case  quoted  that  these 
so-called  glands  are  the  pathway  through  which  the  infection  takes 
place. 

Exception  may  be  fairly  taken  to  the  designation  of  these  structures 
as  glands.  From  studies  made  by  the  writer,  the  assumption  of  their 
glandular  character  does  not  appear  to  be  warranted.  The  cellular 
elements  of  which  they  are  composed,  their  morphology,  and  their 
relation  to  the  embryological  development  of  the  tooth  germ  and  its 
related  tissues  point  to  the  conclusion  that  the  so-called  lymphatics 
of  the  peridental  membrane  are  remnants  of  the  epithelial  sheath  of 
Hertwig,^  which  in  the  adult  membrane  constitute  "rests"  of  epithelial 
debris  having  the  characteristics  of  a  degenerative  tissue.  Examples 
of  embryonal  resting  cells  are  found  in  many  other  locations  in  the 
bod}',  which  under  irritation  are  prone  to  take  on  morbid  activity,  and 
also  by  reason  of  their  degenerate  character  and  low  resistance  are 
under  favorable  conditions  peculiarly  liable  to  infection. 

The  appearance  of  the  structures  in  question  is  clearly  shown  in 
Fig.  559. 

The  epithelial  origin  of  these  so-called  "lymphatics"  is  by  no  means 
a  recent  belief  as  to  their  character  and  significance. 

Magitot^  first  advanced  the  hypothesis  that  the  epithelial  layer 
forming  the  inner  wall  of  c>sts  of  the  peridental  membrane  was  derived 
from  the  wall  of  the  dental  follicle.     IMalassez*  confirmed  and  further 

1  Periosteum  and  Peridental  Membrane,  p.  93. 

^  Ueber  das  Zahnsystem  der  Amphibien,  Archiv.  fiir  mikroskopische  Anatomie, 
Supplementheft,  1874. 

■'  Memoire  sur  les  Kystes  des  Machoires,  Arch,  gener.  de  Medecine,  1872,  tome 
ii,  pp.  339  414  et  681-699;  Memoire,  etc.,  1873,  tome  i,  pp.  154-174  et  437-486. 

^  tSur  I'exi.stence  d'amas  epitheliaux  autour  de  la  rarine  des  dents  chez  I'homme 
adulte  h  I'etat  normal,  Arch,  de  physiol.,  1S85,  tome  i,  p.  129. 


PYOHRHEA   HAVING  A  CONSTITUTIONAL  PREDISPOSITION      497 

extended  the  \it w  of  IMagitot,  while  von  Brunn/  by  a  thorough  and 
elaborate  microscopic  study  of  the  embryological  development  of  the 
dental  follicle,  furnished  the  anatomical  and  histological  data  upon  which 
a  rational  luiderstanding  of  the  i)rocess  by  which  the  ei)ithelial  structures 

Fit;.  559 


Reproduced  from  Fibers  of  the  Peridental  Membrane.  G.  \.  Black,  Dental  Cosmos,  vol.  xli, 
p.  111.  Glands  of  peridental  membrane  shown  with  yj-inch  lens,  in  which  the  characters  of  the 
cellular  elements  appear.  D,  dentin;  C?re,  cementum;  Cb,  cenientoblasts;  Gl  and  GI-,  loops  of 
glands  in  focus  showing  the  cells;  Cp,  hyaline  capsule  enclosing  gland,  which  also  appears 
about  GI-. 


found  in  the  peridental  membrane  are  derived  from  the  embryonal 
epithelial  cells  that  originate  the  enamel  organ  and  are  further  extended 
upon  the  tooth  root,  through  the  peridental  membrane,  to  and  inclusive 
of  the  root  apex  in  the  adult.     Concerning  this  extension  of  epithelial 

*  Ueber  die  Ausdehnuns  des  Schinelzorgans  und  seine  Bedeutung  flir  die  Zahn- 
bildung,  Arch.  f.  inikr.  Anatomic,  Band  xxix,  1887. 
32 


498  PYORRHEA  ALVEOLARIS 

cells,  von  Brunn's  conclusion  as  stated  by  Dr.  AYit/.eH  is  as  follows: 
"  The  enamel  orj?an  extends  not  only  as  far  as  enamel  is  subsequently 
formed,  but  proliferates  beyond  the  limiting  border  of  the  enamel  and 
gradually  covers  the  entire  tooth  germ  up  to  the  apex  of  the  tooth." 
This  proliferation  of  the  enamel  organ  had  already  been  described  by 
(),  Hertwig,^  and  v.  Brunn  adopted  Hertwig's  term  epithelial  sheath 
for  this  sheath-like  epithelial  process. 

Infection  of  the  epithelial  nests  distributed  as  a  network  throughout 
the  structure  of  the  pericemental  membrane  leads  to  inflammatory 
reaction  not  only  of  the  membrane  itself,  but  of  the  bony  alveolar 
walls  and  the  bone  of  the  alveolar  border,  and  the  gingival  tissue  as 
well,  resulting  in  a  series  of  pathological  and  mori)liological  changes  in 
these  structures  characteristic  of  the  destructi\e  disorder,  and  ending 
in  the  loss  by  exfoliation  of  the  involved  teeth. 

With  loss  of  the  teeth  the  disease  is  arrested,  for  the  reason  that  the 
tissue  in  which  the  infection  originates,  viz.,  the  peridental  membrane, 
no  longer  exists  as  a  factor  in  the  process.  For  the  same  reason  extrac- 
tion and  replantation  of  pyorrLctic  teeth  w^ill  effect  a  cure  of  the  dis- 
orders in  connection  with  teeth  so  treated,  the  peridental  membrane 
being  functionally  destroyed  by  the  operation,  union  of  the  replanted 
tooth  to  its  alveolus  being  brought  about  by  ankylosis.  Similarly, 
destruction  of  the  peridental  membrane  and  irritation  of  the  socket 
walls  by  the  excessive  use  of  scalers  results  favorably  to  the  cure  of  the 
disease  by  eliminating  to  a  greater  or  less  degree  the  peridental  mem- 
brane as  a  factor  and  reestablishing  union  between  the  socket  and 
tooth  root  by  bony  encapsulation  or  ankylosis. 

The  exact  nature  of  the  destructive  action  of  the  disease  upon  the 
bony  tissue  of  the  alveolar  sockets  has  not  as  yet  been  definitely  made 
out. 

A.  Hopewell-Smith^  is  of  the  opinion,  based  upon  careful  micro- 
scopic study  of  the  diseased  tissues,  that  "  The  disease  of  the  bone  is  not 
in  its  earlier  stages  a  rarefying  osteitis.  .  .  It  is  essentially  depend- 
ent upon  an  osseous  lesion,  an  atrophy  of  the  hone  which  in  the  thinnest 
parts  causes  the  cervical  margins  of  the  teeth  to  become  denuded 
through  the  halisteresis  (osteomalacia)  and  osteoclastic  absorption. 
The  presence  of  serumal  calculus  is  not  sufficient  in  itself  to  induce  the 
condition,  and  may  not  be  associated  with  it  at  all  as  a  predisposing  or 

1  Ueber  Zahnwurzelcysten  deren  Entstehung,  Ursuche  und  Bchandlung,  Leipzig, 
1S96,  p.  10. 

-  Ueber  das  Zahnsystem  der  Amphibien,  Arch.  f.  mikr.  Anatomie,  Supplement- 
heft,  1874. 

•'  Dental  Cosmos,  vol.  liii,  p.  409. 


PYORRIIKA    IIAVIMI  A   COXSTITCTJOX AL  PREDISPOSITION      499 

exciting  cause."  The  osteoclastic  destruction  of  tlie  aheolar  bone  is 
not  infreciuently  extended  to  the  pericementum,  producing  clearly 
marked  evidence  of  root  absorption  about  the  apical  extremities  of 
teeth  lost  throut,di  pyorrheal  disease. 


^ 


/ 

'  f 

^^^C^.^1 

J 


'M 


A. 


J^ 


Vertical  section  through  canine  and  right  maxilla  of  man,  aged  twenty-eight  years,  showing  latest 
stages  of  extremely  acute  conditions  associated  with  pyorrhea  alveolaris.  Lateral  section  (X35). 
A,  apex  of  root  formed  by  hyperplasia  cementum;  B,  hyperplastic  peridental  membiane;  C, 
indifferent  tissue  enormously  increased  in  amount  and  more  vascular  than  usual;  D,  soft 
medullary  tissue  exhibiting  signs  of  hyperplasia;  E,  large  osteoparotic  space;  F,  sequestrum  of 
bone  undergoing  peripheral  absorption;  G,  osteoclasts  producing  lacunae  absorption  of  the  bone 
of  the  socket;  H,  bone  of  socket  partially  destroyed  and  converted  into  osteoid  tissue;  /,  line 
of  junction  of  decalcified  and  normal  bone.  Preparation  and  photomicrograph  by  A.  Hopewell- 
Smith. 


The  alterations  of  histological  structure  in  the  tissues  involved  in 
pyorrhea  alveolaris  are  shown  in  Fig.  560,  reproduced  from  a  photo- 
micrograph of  a  section  through  the  tooth  root  and  its  retentive  tissues 
by  A.  Hopewell-Smith. 


500  PYORRHEA   ALVEOLARIS 

Destructive  inflammatory  lesions  of  the  ginji^ival  and  alveolar  tissues, 
more  or  less  simulating  pyorrhea  alveolaris,  occasionally  occur,  due  to 
specific  infections;  for  example,  syphilitic  in\asion  oi  the  gingival 
margins,  or  infections  following  the  use  of  mercury  as  an  antisyphilitic 
remedy.^  The  clinical  history  and  the  atypical  appearance  of  these 
lesions  will,  howe\er,  furnish  the  data  necessary  to  a  clear  differential 
diagnosis.  A  form  of  destructive  gingival  and  alveolar  inflammation, 
which  may  be  mistaken  for  an  acute  expression  of  ordinary  pyorrhea 
alveolaris  of  a  phagedenic  type  is  that  produced  by  an  invasion  of 
the  Bacillus  fusiformis  and  spirochete  of  Vincent's  angina.  The  his- 
tory of  the  case  will  show  that  the  inflammatory  attack  is  essentially 
acute  in  character  and  difi'ers  from  ordinary  pyorrhea  alveolaris  in 
that  the  disorder  promptly  yields  to  local  applications  of  iodin  following 
curettement  and  hot  water  irrigations  of  the  necrotic  alveolar  margins. 
In  a  doulitful  case,  bacteriological  examination  of  the  exudate  will 
clear  up  the  diagnosis. 

Finally,  scorbutus,'- both  in  the  adult  and  as  occurring  in  improperly 
fed  children,  produces  a  marginal  gum  and  aheolar  lesion  which  in 
certain  stages  closely  simulates  pyorrheal  disease  of  the  alveolar  border. 
The  history  of  the  attack  and  an  examination  of  the  food  habit,  together 
with  the  existence  of  the  other  lesions  typical  of  scorl)utus,  e.  g.,  hemor- 
rhagic infarcts  of  the  skin  simulating  purjjura  hiemorrhagica,  soreness  of 
the  articulating  ends  of  the  long  bones,  and,  in  children,  motor  paralysis 
enuresis,  etc.,  will  determine  the  nature  of  the  constitutional  disorder 
responsible  for  the  mouth  lesion  and  indicate  the  therapeutic  proce- 
dures necessary  for  the  correction  of  the  disorder. 

The  deep  invasion  of  the  peridental  membrane  by  pathogenic  organ- 
isms in  cases  where  the  defensive  agencies  of  the  body  are  below  normal 
frequently  leads  to  the  protluction  of  abscesses  wdiich  are  extremely 
painful,  causing  much  distress  to  the  patient  during  the  period  of  their 
development,  which  ordinarily  run  a  course  of  from  a  week  to  ten  days, 
although  in  certain  situations  they  may  run  a  shorter  course.  The  pus 
exudate  may  burrow  its  way  between  the  cementuni  and  the  aheolar 
wall  to  the  gum  margin,  in  which  case  the  so-called  pus  pocket,  or  pyor- 
rheal pocket,  is  formed  as  the  fistulous  outlet;  or  when  the  focus. of 
infection  is  located  near  the  root  apex  in  the  case  of  a  tooth  so  situated 
that  the  line  of  tissue  resistance  between  the  focus  of  infection  and  the 
gum  margin  is  greater  than  that  l)etween  the  focus  of  infection  and  the 

'See  A.  Loup,  ('(jusidcratioiis  on  the  Role  t)f  Mcrcurv  in  MiTcurial  Stomatitis 
Dental  Cosmos,  1900,  xlii,  1300. 

-Kirk,  E.  C,  Two  Cases  of  Infantile  Sforbwtiis,  I)<>n1al  Cosmos,  xxxvii,  1895, 
489,  and  discussion,  \^\^.  ^^Y.^  to  f)!  1 , 


PYORRHEA   IIAVIXG  A   CONSTITUTIONAL   PREDISPOSITION      501 


c)\'('cl\  iug  i^um  surfacr,  tluMi  the  fistulous  outlet  takes  ])laee  iipou  the 
free  guui  .suit'a((\  and  the  ease  Ix'conies  one  of  so-ealled  abscess  upon  a 
tooth  with  a  vital  i)ulp,  or,  as  designated  by  Dr.  I).  ]).  Smith,  ;i  peri- 
cemental abscess.^ 


I'i'T.  501 


Fi<:.  562 


Fi<:.  503 


Specimens  showing  periceuiental  abs 


at  A,  B,  and  C  respectively. 


Fig.  564 


Fig.  564  will  indicate  diagrammatically  the  relation  of  the  locus  of 
infection  to  the  resistance  of  the  surrounding  tissue  in  determining  the 
part  of  the  fistulous  outlet.  --1  represents  an  inflammatoiy  focus  near  the 
root  apex  with  fistulous  outlet  upon  the  free  gum  surface.  B,  a  similar 
inflammatory  focus  near  the  anatomical  neck  of  the  tooth  with  fistulous 
outlet  at  the  gingival  margin  D.  The  etiology 
and  pathology  of  both  lesions  is  the  same; 
they  differ  clinically  by  reason  of  the  location 
of  the  point  of  fistulous  discharge  due  to  loca- 
tion of  the  initial  lesion.  In  the  case  of  the 
lesion  ^4.,  the  fistulous  outlet  would  have  oc- 
curred at  the  gingival  margin  C  had  the  part 
of  resistance  toward  C  been  less  than  toward 
the  gum  surface  over  A. 

]\Iuch  confusion  as  to  the  pathological  sig- 
nificance of  these  abscesses  has  arisen  by 
reason  of  the  fact  that  they  occur  upon  teeth  with  \'ital  pulps.  Their 
relation  to  pyorrhea  alveola  ris  is,  howe\'er,  perfectly  clear,  and  the 
clinical  phenomena  which  they  manifest  are  due  solely  to  the  depth 
of  the  bacterial  invasion  which  is  the  exciter  of  the  suppurative  pro- 
cess, this  deep  invasion  leading  ultimately  to  a  fistulous  outlet  upon 


D.  D.  Smith,  Pericemental  Abscess,  Dental  Cosmos,  1897,  xxxix,  569. 


502  I'YORRIIEA   ALVEOLA RIS 

the  gum  surface  instead  of  at  the  gum  margin,  with  pocket  formation, 
as  onUnarily  occurs  where  tlie  invasion  is  of  kss  depth. 

Bacteriological  examination  of  the  pus  taken  from  a  Hmited  number 
of  cases  of  pericemental  abscess  showed  pneumococci  and  staphylococci 
as  the  principal  organisms,  and  these  may  be  regarded  as  the  exciters 
of  the  inflammatory  process.  The  pericemental  abscess  is  typical  of 
that  form  of  pyorrhea  aheolaris  associated  with  a  constitutional  pre- 
disposition or  systemic  fault  due  either  to  bodily  disease  or  to  nutri- 
tional or  metabolic  ernjr,  which  has  reduced  the  defensive  agencies 
of  the  body  below  normal  and  thus  rendered  deep  in\asion  of  the  reten- 
tive tissues  by  pathogenic  bacteria  possible.^ 

Pyorrhea  alveolaris  may  constitute  a  cause  of  malnutrition,  or  it  may 
be  a  result  of  malnutrition.  Infection  of  the  gingi\al  and  alveolar 
tissues  by  pyogenic  and  other  pathogenic  organisms,  besides  leading  to 
the  inflammatory  destruction  of  the  involved  tissues,  coincidently  leads 
to  the  production  of  toxic  end  products  of  bacterial  activity,  which, 
taken  into  the  circulatory  system,  either  directly  from  the  seat  of 
infection  or  via  the  digestive  tract,  set  up  a  chronic  toxemia  of  greater 
or  less  mtensity  which  in  time  may  lead  to  pronounced  disturbances  of 
health,  both  local  and  general,  and  not  infrequently  to  metastatic 
infections,  causing  grave  disease  manifestations  in  various  tissues  and 
organs  of  the  body.  For  which  reason,  thorough  and  systematic  treat- 
ment, directed  toward  the  correction  of  the  local  pyorrheal  disorder, 
should  be  persistently  carried  on  until  the  disease  is  imder  control.^ 
On  the  other  hand,  certain  forms  of  pyorrhea  alveolaris  are  distinctly 
local  expressions  of  faulty  nutrition,  and  particularly  of  that  type  which 
in  its  collective  or  general  expression  is  designated  the  arthritic  diathesis 
or  gouty  diathesis,  characterized  by  a  subnormal  oxidizing  power  and 
in  which  the  pathological  manifestations  are  of  the  class  known  as 
diseases  of  suboxidation.  Cases  of  this  class  present  a  form  of  general 
malnutrition  in  which  the  metabolic  mechanism  appears  to  be 
incapable  of  completely  converting  proteid  materal  into  its  normal 
physiological  end  products,  with  the  result  that  the  whole  of  the  excess 

1  For  a  fuller  discussion  of  pericemental  abscess  consult  the  followiiifi: 

Magitot,  E.  Memoires  sur  les  tumcurs  pcrioste  dentairc  et  sur  rosteo-periostite 
alveolo-dentaire,  Paris,  1S73. 

Essig,  Chas.  J.  Some  Causes  of  Loss  of  the  Teeth  in  the  Adult,  Dental  Cosmos, 
1880,  xxii,  130. 

Darby,  Edwin  T.  Proc.  Odontological  Society  of  Pennsylvania,  February,  1880, 
in  Dental  Cosmos,  1880,  xxii,  248. 

Kirk,  Edward  C.  Abscess  upon  Teeth  with  Living  Pulps,  Dental  Cosmos,  1898, 
xl,  621;  Pericemental  Abscess,  Dental  Cosmos,  1900,  xlii,  1149. 

-See  Oral  Sepsis  as  a  Cause  of  Septic  Gastritis,  Toxic  Neuritis,  and  Other  Septic 
Conditions,  by  Dr.  Wm.  Hunter,  Physician  to  St.  George's  Hospital,  London. 
London  and  New  York,  Cassell  &  Co.,  1901. 


PYORRHEA  lIAVlSa  A  CONSTITUTIONAL  PREDISPOSITION      503 

nitrogen,  instead  of  leaA'ing  the  body  as  urea,  a  soluble  bland  and 
non-irritating  waste  product,  is  partially  retained  and  deposited  in 
various  of  the  tissues  as  members  of  the  purin  group  and  allied 
relatively  insoluble  compounds,  which  in  certain  positions  become 
sources  of  chemical  and  mechanical  irritation  leading  to  cell  death, 
so-called  necrobiosis  of  tissue  elements,  and  by  thus  establishing  areas 
or  loci  of  diminished  resistance  become  the  forerunners  of  local  in- 
fections. 

Chemical  and  microscopic  examination  of  the  tartar  deposits  upon 
tooth  roots  from  patients  of  the  class  under  consideration  has  amply 
demonstrated  the  presence  of  urates  as  the  nucleus  around  which  the 
deposit  of  calcic  phosphate  has  taken  place,  thus  confirming  the  arthritic 
origin  of  the  lesion,  which  in  its  pathological  character  is  strictly  the 
analogue  of  the  tophus  of  true  gout. 

Pyorrhea!  lesions  of  the  arthritic  type  are  relatively  deep-seated,  and 
less  inclined  to  be  marginal  in  their  expression.  The  case  presents  a 
history  of  soreness  and  lameness  and  increasing  looseness  of  the  teeth, 
w^th.  but  little  or  no  visible  pus  formation.  Atrophic  changes  in  the 
alveolar  walls  become  progressively  manifest,  and  from  time  to  time 
local  tumefactions  and  swellings,  indicating  pus  formation,  occur  over 
the  roots  of  the  more  noticeably  affected  teeth.  These  acute  localized 
inflammatory  tumefactions  may  or  may  not  develop  into  abscess  for- 
mations. 

In  the  earlier  stages  of  these  localized  lesions  the  inflammation 
frequently  subsides  without  discharge  of  the  pus  exudate,  but  later 
the  swelling  recurs,  and  in  due  course  a  minute  abscess  discharges  its 
exudate  upon  the  free  gum  surface,  after  which  resolution  or  healing 
of  the  inflamed  area  takes  place,  to  be  repeated  later,  with  more  exten- 
sive involvement,  until  the  tooth  is  finally  lost. 

Teeth  extracted  after  having  passed  through  the  cycle  of  inflammatory 
phenomena  here  described  will  frequently  show  upon  some  portion  of 
the  root  near  the  apex  tartar  formations  even  though  there  may  have 
been  no  break  of  continuity  in  the  attachment  of  the  peridental  mem- 
brane and  gum  tissue  at  the  anatomical  neck  of  the  tooth.  The  tartar 
deposits  in  such  cases  are,  therefore,  unquestionably  not  salivary  in 
origin,  but  are  derived  from  the  liquor  sanguinis,  and  are  properly 
designated  as  serumal  or  sanguinary  tartar.  Their  mode  of  formation 
is  explainable  upon  the  same  basis  as  the  calcic  formations  that  are 
found  in  old  abscess  cavities  in  other  tissues  of  the  body,  notably  in  the 
lung,  lymphatic  glands,  etc.  Chemical  and  microscopic  examination 
of  these  concretions  in  connection  with  the  cHnical  historv  of  the  cases 


504  PYORRHEA   ALVEOLAR/S 

of  pyorrhea  ahcolaris,  in  which  they  occur,  throws  considerable  light 
111)011  tlie  method  of  tiieir  formation.  It  is  a  well-estahlished  ])Jiysio- 
lo^ical  fact  tJiat  a  tissue,  such  as  muscle  or  li<;ainentous  tissue,  doinj; 
actixe  woi'k  rapidly  undergoes  metabolic  chang(>s  while  iii  action,  and 
that  in  consequence  of  the  increased  oxidation  involved,  the  reaction 
r)f  the  tissue  tentls  toward  acidity  or  relatively  lessened  alkalinity. 
Under  these  circumstances  an  area  of  lessened  alkalinity  in  the  tissues 
of  an  arthritic  individual  whose  blood  stream  is  carrying  dissolved  urates 
to  the  saturation  point  becomes  a  nidus  in  which  precipitation  of 
urates  takes  place.  Irregular  position  of  a  tooth,  or  liabit  of  the  indi- 
vidual, will  subject  a  gi\  en  tooth  to  more  than  its  physiological  share 
of  the  burden  of  work  in  mastication,  and  thus  make  it  the  point  of 
selection  for  a  uratic  deposit  by  developing,  through  o\erwork  of  a 
particular  tooth,  an  area  of  decreased  alkalinity  in  its  investing  peri- 
dental membrane  and  thus  make  it  the  point  of  selection  or  deter- 
mination of  the  pyorrheal  attack,  just  as  the  articulation  of  the  distal 
phalanx  of  the  great  toe,  from  the  relati\e  i)r()minence  of  its  part  in 
walking,  becomes  the  point  of  selection  for  a  localized  acute  inflamma- 
tory manifestation  in  classic  gout.  Deposition  of  urates  in  the  selected 
area  is  followed  by  localized  cell  irritation  and  limited  cell  death,  and 
the  disturbed  area  constitutes  a  lucus  minoris  res i stent m  in  which  in- 
fection takes  place  and  the  suppuratixe  phenomena  alx'eady  described 
follow.  Where  resolution  takes  place  in  one  of  these  areas  without 
formation  of  fistula,  caseation  by  dehydration  of  the  retained  abscess 
debris  takes  place,  and  final  infiltration  of  the  mass  by  calcic  salts 
occurs  by  reason  of  the  fact  that  the  mass  is  now  alkaline  in  reaction, 
due  to  the  pus  formation,  and  the  final  result  is  a  tartar  nodule  hav- 
ing a  nucleus  of  uratic  salts  around  which  has  been  deposited  a  mass  of 
tricalcic  phosphate  boinid  together  ])y  the  organic  residue  of  the  }>us 
exudate. 

The  close  relationship  of  arthritic  malnutrition  to  pyorrheal  involve- 
ment of  the  retentive  tissues  of  the  teeth  is  now  clearly  recognized,  and 
the  constitutional  predisposition  induced  by  arthritism  to  bacterial 
invasion  is  found  to  be  (le|)endent  upon  a  diminished  tissue  resistance 
with  lowering  of  the  opsonic  index,  which  in  many  cases  is  amenable 
to  autogenous  vaccine  therapy,  under  which  treatment  the  opsonic 
index  has  been  raised  to  normal  with  cure  of  the  local  lesion.' 

While  arthritic  individuals,  especially  those  whose  dietary  is  over- 

'  See  The  Association  of  Disease  of  the  Mouth,  witii  Rheuiiuitoitl  Arthritis  and 
other  Forms  ot  Rheuniatism,  Hunterian  Lecture,  by  Kenneth  W.  CJoodby,  Lancet, 
March  11,  1911,  p.  G:5<);  also  Arthritism,  by  E.  C.  Kirk,  DnU-.A  Cosmos,  July,  1009. 


TREATMENT  OF   ALVEOLAR  PYORRIIEAL  IXFECTIOKH     505 

balanced  on  the  ])r()ttM<I  side,  rvprosciit  a  type  of  inalmitrition  ^\■lli(•h 
renders  tlieni  especially  liable  to  infect  ion  of  tlu>  aUeolar  tissues  by 
pyoijenie  ortfanisms,  it  may  be  stated,  as  a  broad  principle,  that  any 
nutritional  disorder  which  results  in  depression  of  the  natural  defensive 
agencies  of  the  body,  when  sufficiently  prolonged,  is  liable  to  become  a 
predisposing  cause  of  pyorrhea  aheolaris.  Rhein'  has  directed  atten- 
tion to  this  relationship  of  constitutional  ])redisposition  arising  out  of 
various  systemic  diseases,  and  has  suggested  a  basis  of  classification  of 
pyorrheal  lesions  as  related  to  their  etiology  in  that  connection.^ 

Nutritional  disturbance  from  neuroses,  hereditary  predisposition,  and 
developmental  errors  have  been  shown  by  Talbot^  to  act  as  etiological 
factors  leading  to  pyorrheal  infection  of  the  alveolar  structures. 


TREATMENT    OF    ALVEOLAR    PYORRHEAL   INFECTIONS    HAVING 
A   SYSTEMIC  PREDISPOSITION 

It  is  a  fimdamental  axiom  of  therapeutics  that  the  cure  of  a  disease 
must  involve  the  removal  of  its  cause.  As  the  ciu-e  of  suppurative 
inflammatory  lesions  of  the  retentive  structures  of  the  teeth  due  to  the 
impingement  of  tartar  as  a  traumatic  predisposing  cause  necessarily 
involves  the  thorough  removal  of  tartar  deposits  as  a  prerequisite  to 
successful  local  treatment  of  the  inflammatory  lesion,  so  also  in  pyor- 
rhea aheolaris,  due  to  constitutional  malnutrition,  treatment  of  the 
local  lesion  is  without  permanent  curative  eftect  until  the  underlying 
systemic  fault  has  been  ett'ectually  corrected.  The  mere  routine  local 
treatment  by  scaling  and  the  application  of  antiseptic,  stimulant, 
escharotic,  or  astringent  drugs  is  of  but  temporary  benefit;  indeed, 
misdirected  or  ill-judged  routine  local  treatment  may  do  positive  harm 
in  cases  of  this  class.  A  large  proportion  of  pyorrheal  cases  ha^'ing 
a  constitutional  predisposition,  cases  of  the  most  intractable  class 
have  practically  no  tartar  deposits  whatever  upon  the  tooth  roots,  and 
yet  the  empiric  to  whose  mind  tartar  and  pyorrhea  are  interchangeable 
terms,  subjects  such  teeth  to  a  vigorous  application  of  the  scaler  to 
scrape  the  roots  smooth  e\en  when  no  tartar  is  to  be  foinid  upon  them. 
Such  ill-advised  treatment  Mounds  the  gingi\'al  tissues,  increases  the 

1  Oral  Expressions  of  Malnutrition,  Dental  Cosmos,  1S96,  xxxviii,  4S6;  Pyorrhea 
Alveolaris,  Dental  Review,  March,  1899. 

2  An  Etiological  Classification  of  Pj^orrhea  Alveolaris,  Dental  Cosmos,  1894, 
xxxvi,  779. 

■'  See  Interstitial  Gingivitis  or  Pj-orrhea  Alveolaris,  by  Eugene  S.  Talbot,  M.D., 
D.D.S.,  1899. 


5()() 


r  YOIilillEA    AL  VKOLAUI^^ 


FiQ.  o65 


()l)p()rtunity  for  furtlief  infection,  and  lessons  tlie  already  weakened 
resistive  powers  of  the  local  tissue  area  involved.  Careful  exploration 
with  a  suitable  delicately  fashioned,  exploring  instrument  should  be 
made  to  first  determine  the  presence  or  absence  of  tartar  deposits  before 
any  attempt  at  scaling  in  these  cases  is  made.  Where  tartar  is  not  the 
obvious  cause  of  the  pyorrheal  lesion,  careful  study  of  the  character  of 
the  local  gingival  conditions  should  be  made,  the  quantity  and  character 
of  the  pus  flow  should  be  noted,  and  the  extent  of  atrophy  or  rarefaction 
of  the  alveolar  borders  determined.  For  the  latter  purpose  the  radio- 
graph is  a  most  valuable  aid  in  diagnosis  (Fig.  5(55),  Where  it  is  possible 
to  do  so,  cultures  from  the  exudate  should  be  made  and  the  nature  of 
the  infecting  organisms  determined.  The  history  of  the  patient,  the 
existence  of  systemic  disease,  or  nutritional  fault  should  be  ascertained, 

and  where  doubt  exists  as  to  the  nutri- 
tional or  metabolic  status  of  the  patient,  a 
careful  urinary  and  salivary  analysis  should 
be  made. 

An  almost  unlimited  number  of  antisep- 
tic drugs  have  been  suggested  and  tried  for 
disinfecting  the  pus  pockets  and  infected 
tissues  in  pyorrheal  cases.  Many  are  ob- 
jectionable for  the  reason  that  they  exert 
a  destructive  action  upon  the  tissue  cells 
as  well  as  upon  the  invading  pathogenic 
organisms.  The  ideal  antiseptic  is  one 
that  will  exert  a  destructive  effect  upon 
the  bacteria  without  injury  to  the  tissue 
and  at  the  same  time  have  diffusive  or 
penetrating  power  sufficient  to  enable  it  to  reach  the  organisms  deeply 
embedded  in  the  infected  tissues.  Among  the  more  recent  remedies 
which  have  been  favorably  reported  upon  is  bismuth  subnitrate  made 
into  a  paste  with  vaselin,  the  formula  being  Bismuth  subnitrate,  33 
per  cent.;  vaselin,  67  per  cent. 

This  preparation  injected  by  means  of  a  warmed  syringe  into  pockets 
and  sinuses  has  been  found  to  arrest  pus  formation  markedly,  and 
cures  of  alveolar  pyorrhea  are  reported  from  its  use.' 

Another  preparation  which  practical  test  has  shown  to  have  a  marked 
value  for  the  same  use  is  silver  iodid  of  5  per  cent,  strength  in  an  emul- 
sion made  with  Irish  moss  (Chondrus).     The  preparation  was  first 


Radiograph  of  the  alveolar  border 
of  a  patient  suffering  from  pyorrhea 
alveolaris,  in  which  the  rarefaction 
of  the  bony  tissue  due  to  decalcifica- 
tion is  clearly  shown.  Note  also  the 
resorption  of  the  apex  of  the  right 
canine  root. 


iSee  Bismuth  Paste  as  a  Dontal  Therapeutic  Agent,  Rudolf  Beck,  D  D.S.,  Dental 
Review,  1909,  xxiv,  1079. 


TREAT MENT  OF  ALVEOLAR  I'YORRHEAL   INFECTIONS     507 


Fici.  566 


eiiipl()y(>(l  ill  tlie  treatment  of  urethritis  in  ueeordance  with  X\\v.  following 

foruuila: 

^. — Arf>;onti  nitrutis  piilv., 

Potassii  iodidi aa  p;r.  Iv 

AqiKR  (lost 3v,j 

Mucilago  chondri q.  s.  fSiij 

Dissolve  the  potassium  iodid  in  all  of  the  water  and  gradually  add 
the  silver  nitrate  in  powder,  shaking  after  each  addition  until  all  of  tiie 
silver  nitrate  is  dissolved,  then  add  the  mucilage  and 
shake  thoroughly.  This  method  of  compounding  the 
emulsion  is  necessary  in  order  to  obtain  the  precipi- 
tate of  silver  iodid  in  an  extremely  finely  divided 
state  and  keep  it  in  suspension.  The  emulsion  should  be 
kept  away  from  strong  light. 

For  the  application  of  medicaments  to  the  infected 
pockets  and  sinuses  in  pyorrhea  cases  the  device  known 
as  the  "pyorrhea  pen"  is  a  most  convenient  and 
efficient  means  (Fig.  566) .  The  instrument  consists  of 
a  suitable  handle  in  which  is  fixed  a  split  metal  holder, 
which  by  means  of  a  rectangular  sliding  collar  is  made 
to  grasp  a  pen-like  double  point  of  pyralin,  the  two 
leaves  of  which  form  a  capillary  space  between  them. 
The  flexible  points  may  be  used  either  in  single  or 
double  form,  and  because  of  the  convex  shape  given 
to  them  by  the  clamping  device,  when  dipped  in  the 
remedy  a  sufficient  quantity  is  retained  in  the  spoon- 
shaped  depression  and  between  the  two  points  for 
application,  without  a  surplus  to  overflow  and  spread 
upon  surrounding  healthy  tissues. 

A  quantity  of  points  is  furnished  with  each  instru- 
ment so  that  a  new  point  may  be  used  with  each  case. 
They  may  be  altered  in  position  with  reference  to 
the  grasp  of  the  holder,  for  greater  convenience  in 
reaching  difficult  cases,  or  altered  in  form  by  reshaping 
with  scissors  for  special  situations  as  needed. 

In  all  cases  where  the  progress  of  the  disease  has 
resulted  in  appreciable  loosening  of  the  teeth,  the  local 
treatment  should  be  supplemented  by  some  means 
for  affording  surgical  rest  to  the  teeth  until  reestab- 
lishment  of  healthful  condition  of  the  tissues  has 
rendered  them  firmer  in  their  sockets  and  capable 
of  withstanding  the  ordinary  stress   of  mastication.  rhea  pen. 


5()S  I'YOh'h'JU'JA    ALVEOLARIS 

A  variety  of  means  for  sj)lintiiig  the  loosened  teeth  have  heen 
sii^jjested,  and  many  ingenious  meclianieal  apphanees  have  been 
(le\  ised  for  that  purpose.  It  is  be^^ond  the  scope  of  this  chapter  to  take 
up  in  detail  the  construction  of  these  appliances,  and  for  information 
upon  that  class  of  work  the  reader  is  referred  to  standard  works  on 
mechanical  dentistry.  A  simple  and  effecti\e  device  for  securing  surgical 
rest  of  pyorrhetic  te(>th  during  the  stage  of  healing  and  recuperation  of 
their  alveolar  structures  consists  in  weaving  a  floss  silk  ligature  about 
the  disordered  teeth  so  as  to  include  one  or  more  sound  teeth  at  each 
end  of  the  series  of  loose  teeth,  making  several  figure-of-eight  turns 
of  the  ligature  throughout  the  whole  series,  and  then  painting  the  liga- 
ture with  a  thick  solution  of  celluloid  in  acetone,  which  rapidly  hardens 
and  makes  an  efiecti^'e  supporting  splint  that  will  not  become  loosened 
or  deteriorate  in  many  cases  for  two  or  three  months.  It  should  be 
understood  that  in  placing  the  above  described  splint,  the  surfaces  of 
the  teeth,  the  ligature,  etc.,  should  be  kept  dry  until  thorough  hardening 
of  the  celluloid  solution  has  taken  place.  The  drying  of  the  solution 
may  be  hastened  by  ai)plications  of  a  warm  air  blast. 

It  is  obviously  without  the  spiiere  of  the  operative  dental  practi- 
tioner to  undertake  the  treatment  of  the  underlying  constitutional 
aberrations  that  predispose  to  alveolar  infections;  it  is,  however,  dis- 
tinctly WMthin  his  province  to  be  able  to  recognize  intelligently  these 
mouth  lesions  as  indications  of  general  bodily  disease  or  nutritional 
errors,  and  to  be  able  not  only  to  direct  the  patient  to  a  physician  for 
treatment,  but  also  to  aid  in  the  diagnosis  of  the  systemic  fault  by  reason 
of  his  knowledge  of  the  relationship  of  the  various  ol)jective  phenomena 
or  symptoms  presented  by  these  aheolar  lesions  to  the  several  systemic 
states  with  Mhich  they  are  connected.  In  order  that  the  dentist  may 
secure  the  training  necessary  to  fit  himself  to  diagnose  correctly  the 
nature  of  these  alveolar  lesions,  it  is  essential  that  he  cooperate  with  the 
physician  and  keep  in  touch  with  the  medical  treatment  of  the  case, 
while  the  local  dental  treatment'  is  being  concuriently  carried  out.  The 
knowledge  gained  from  the  medical  study  and  treatment  of  the  systemic 
condition  will  in  due  course  enable  the  dental  practitioner  to  determine 
from  a  study  of  the  mouth  lesion,  the  general  and  often  the  special  nature 
of  the  constitutional  fault  which  is  the  underlying  predisposing  factor 
in  the  case,  and  when  armed  with  such  knowledge,  enable  him  also  to 
point  out  often  constitutional  disorders  in  their  earlier  stages  and  before 
the  patient  has  otherwise  become  aware  of  their  existence. 

The  question  of  the  curability  of  the  type  of  pyorrheal  disorder  here 
under  consideration  is  so  frequently  the  subject  of  discussion,  and  its 


VACCINE  THERAPY  OF  ORAL  INFECTIONS  509 

solution  depends  so  obviously  upon  the  scope  of  meaning  that  may  be 
attached  to  the  term  cure,  that  it  is  important  to  briefly  and  definitely 
consider  the  matter  here. 

Where  the  ah'eolar  infection  is  consequent  upon  a  lowered  vital  resist- 
ance of  the  infected  tissues  due  to  constitutional  disease  or  general 
malnutrition,  local  treatment,  while  it  may  arrest  the  progress  of  the 
disorder  temporarily  or  keep  it  under  control  for  a  variable  period  of 
time,  cannot  alone  effect  a  cure  in  the  sense  that  the  tendency  to  a 
recurrence  of  the  disorder  is  permanently  eradicated.  The  permanent 
cure  of  this  type  of  pyorrhea  alveolaris  necessitates  the  eradication  of 
its  predisposing  constitutional  cause  just  as  the  permanent  cure  of 
pyorrhea  due  to  infection  consequent  upon  tartar  deposits  necessitates 
the  removal  of  the  tartar  as  a  predisposing  cause.  In  either  case,  where 
the  predisposing  cause  is  constantly  operative,  local  treatment  alone, 
which  is  necessarily  intermittent,  will  ultimately  fail  to  effect  a  perma- 
nent cure.  When  both  the  predisposing  cause,  be  it  local  or  systemic, 
and  the  local  infection  can  be  eradicated,  the  disorder  is  unquestionably 
curable. 

When  the  lowered  resistance  of  the  patient  is  mainly  due  to  absorp- 
tion of  toxins,  and  when  the  resulting  malnutrition  is  not  due  to  specific 
constitutional  disease,  prompt  and  permanent  restoration  of  the  infected 
gingival  tissues  to  health  may  be  brought  about  by  the  judicious  appli- 
cation of  vaccine  therapy.  So  satisfactory  has  this  method  of  treat- 
ment proved  in  a  fair  proportion  of  otherwise  intractable  cases,  that 
the  following  description  of  the  method  is  here  appended: 

VACCINE  THERAPY  OF  ORAL  INFECTIONS^ 

In  common  with  other  local  pathological  conditions,  brought  about 
through  the  agency  of  bacteria,  affecting  various  parts  of  the  exterior 
and  interior  of  the  animal  economy,  certain  infections  of  the  oral 
cavity  and  its  adnexa  coming  within  the  domain  of  the  dental  prac- 
titioner are  amenable  to  the  action  of  bacterial  vaccines — not 
only  those  due  primarily  to  the  invasion  of  the  tissues  by  pathogenic 
bacteria,  but  also  conditions  in  which  such  organisms  are  present  as 
secondary  invaders  of  a  pathological  process  originally  due  to  some 
other  deleterious  agent.  In  the  treatment  of  these  conditions  the 
mistake  is,   however,   frequently  made  of   de})ending  entirely  on  the 

1  This  addition  to  the  chapter  on  Pyorrhea  Alveolaris  is  contributed  by  Nathaniel 
Gildersleeve,  M.D.,  Assistant  in  the  liacteriological  Laboratory,  University  of 
Pennsylvania. 


510  PYORRHEA   ALVEOJ.ARIS 

vaccines  and  instituting  no  other  local  or  general  therapeutic  measures 
in  combating  the  diseased  conditions;  if  tliis  procedure  is  adhered  to 
the  results  of  bacterical  therapy  will,  in  a  large  percentage  of  cases,  be 
disappointing. 

]\Ianifestly,  bacterial  vaccines  will  not  exert  a  curative  action  on 
factors  other  than  bacterial,  entering  into  a  causative  relationship  to 
diseased  conditions;  inoculations  will  frequently  eliminate  the  bacterial 
element  and,  in  so  far  as  the  infective  nature  of  the  condition  is  con- 
cerned, bring  about  a  marked  improvement  or  cure;  lea\ing,  howe\"er, 
the  predisposing  factors  unchanged  and  still  capable  of  exerting  an 
irritati\e  action  on  the  tissues,  paving  the  way  for  a  fresh  infection 
to  be  grafted  into  the  process.  These  points  are  of  as  much  importance 
in  connection  w4th  oral  infections  as  with  those  occurring  in  other  parts 
of  the  economy. 

In  considering  the  subject  of  vaccine  treatment  of  oral  infections 
there  are  certain  principles  which  the  operator  should  have  firmly 
fixed  in  his  mind,  and  from  which  he  must  not  depart  if  satisfactory 
results  are  to  be  expected.    The  most  important  of  these  are  as  follows : 

I.  A  thorough  familiarity  with  all  pathogenic  organisms  capable  of 
causing  infections  in  the  oral  cavity  and  surrounding  tissues;  with  the 
different  species  concerned  in  the  various  types  of  infection  and  with  all 
pathological  conditions  in  which  bacteria  may  be  present  as  secondary 
invaders. 

II.  A  knowledge  of  the  types  of  infection,  and  the  toxic  substances 
produced  by  the  various  organisms,  together  with  the  various  types  of 
immunity  active  against  each  species.  Such  knowledge  will  prevent 
the  oi)erator  employing  a  vaccine  in  attempting  to  combat  the  ravages 
of  an  organism  against  which  these  substances  will  not  immunize. 

III.  Always  become  satisfied,  by  microscopic  examination  and 
cultural  methods  of  the  exact  nature  and  identity  of  the  organism  or 
organisms  concerned  in  the  individual  infection  under  treatment. 

IV.  Use  vaccines  known  as  autogenous,  i.  e.,  vaccines  prepared  from 
the  pathogenic  organisms  isohited  from  each  case;  and  if  more  than  one 
species  is  present,  to  which  may  be  ascribed  an  etiological  relationship 
to  the  condition,  employ  a  mixed  vaccine  or,  separately  vaccines  pre- 
pared from  each  organism.  He  should  not  depend  on  stock  vaccines 
or  treat  any  case  empirically. 

V.  Exercise  judgment  and  discretion  as  regards  the  dosage  and 
interspacing  of  inoculations,  watching  the  patient's  condition  carefully, 
and  always  be  in  a  position  to  control  the  injections  by  determining 
and  interpreting  the  opsonic  index. 


VACCINE  THERAPY  OF  ORAL  INFECTIONS  511 

"\'I.  Employ  in  conjunction  with  the  vaccines  otlier  local  and  gen- 
eral therapeutic  measures  capable  of  exerting  a  curative  influence 
on  the  process,  removing,  as  completely  as  possible,  all  sources  of 
irritation. 

^'II.  Always  take  into  consideration  the  patient's  general  condition. 
There  are  frequently  underlying  systemic  factors  lowering  the  resistance 
of  the  tissues,  thus  paving  the  way  for  local  infections. 

For  methods  of  isolating  and  identifying  the  various  organisms,  the 
reader  is  referred  to  one  or  another  of  the  works  on  the  subject  of 
bacteriology,  as  an  attempt  to  enter  into  a  detailed  description  of  such 
methods  would  involve  the  WTiting  of  a  text-book  on  the  subject.  A 
few  points  of  importance  regarding  plating  media  for  the  isolation  of 
bacteria  from  the  oral  cavity  had  perhaps  best  be  mentioned.  There 
are  organisms,  playing  an  important  part  in  infections,  inhabiting  the 
oral  cavity  which  many  fail  to  isolate,  for  the  reason  that  suitable  media 
are  not  employed.  Notable  among  these  is  the  pneumococcus.  Milk 
agar,  milk  serum  agar,  blood  serum  agar,  or  blood  agar  should  be 
employed  routinely  when  dealing  with  bacteria  of  the  oral  cavity,  and 
the  cultures  incubated  at  37°  C,  under  both  ordinary  and  anaerobic 
conditions. 

These  media  are  readily  prepared  by  keeping  on  hand,  in  tubes  con- 
taining about  5  c.c,  sterile  milk,  milk  serum,  and  blood  serum,  and 
adding  one  or  another  of  them  to  tubes  of  a  2  per  cent,  nutrient  agar, 
after  it  has  been  liquified  and  cooled  to  42°  C,  in  the  proportion  of 
1  part  to  3  parts  of  the  nutrient  agar. 

Preparation  of  Vaccines. — In  the  preparation  of  vaccines  all  apparatus, 
containers,  and  solutions  employed  must  be  sterile,  and  great  care 
taken  to  prevent  extraneous  organisms  from  gaining  access  to  the 
vaccines. 

Several  slant  cultures  are  made  on  the  surface  of  tubes  of  suitable 
media,  from  a  freshly  isolated  pure  culture  of  the  organism,  and  incu- 
bated at  37°  C.  for  from  eighteen  to  twenty-four  hours;  the  organisms 
are  then  washed  from  the  surface  of  the  media  with  0.S5  per  cent, 
sodium  chloiid  solution  and  transferred  to  a  sterile  bottle  or  test- 
tube  containing  sterile  glass  pearls  or  a  small  amount  of  clean  sterile 
sand.  The  container  is  now"  tightly  stoppered  or  sealed  and  shaken, 
either  by  hand  or  in  a  mechanical  shaker,  for  the  purpose  of  breaking 
up  clumps  and  producing  a  homogeneous  distribution  of  the  bacteria 
throughout  the  suspension.  A  small  amount  of  the  suspension  is  then 
removed  and  the  number  of  bacteria  per  cubic  centimeter  estimated 
by  counting  with  a  Thoma-Zeiss  hemocjiiometer,  using  a  counting  cell 


512  I'VOlililJEA   ALVEOLARIS 

of  -Jo"  mi»-  (lei)tli;  or  by  mixing,  in  a  eapillaiy  pipette,  equal  parts  of  the 
bacterial  suspension,  2  per  cent,  sodium  citrate  solution  and  blood 
obtained  by  puncturing  the  finger  or  lobe  of  the  ear,  this  mixture 
is  spread  thinly  on  slides,  fixed  and  stained  by  an  appropriate 
method. 

The  number  of  bacteria  and  erythrocytes  in  100  microscopic  fields 
are  counted  with  the  aid  of  a  yV  oil  immersion  lens  and  the  number 
of  bacteria  per  cubic  centimeter  estimated  by  a  mathematical 
deduction  assumhig  that  1  c.c.  of  blood  contains  5,000,000,000 
erythrocytes.^ 

The  suspension  of  bacteria  is  next  placed  in  a  tube,  the  end  sealed, 
and  the  tube  immersed  in  a  water  bath  and  heated,  at  approximately 
the  lowest  thermal  death  point  of  the  organism,  for  a  sufficient  period  to 
kill  the  bacteria.  The  suspension  is  then  diluted  to  the  desired  strength,^ 
with  0.85  per  cent,  sodium  chlorid  solution,  0.2  per  cent,  of  phenol  or 
tricresol  added,  subcultm-es  made  for  the  purpose  of  determining  its 
sterility,  and  the  vaccine,  which  we  now  call  the  bacterial  suspension, 
pipetted  into  1  c.c.  ampoules,  which  are  then  sealed,  making  a  closed 
container,  which  cannot  become  contaminated.  The  suspension  is 
diluted  to  the  extent  that  1  c.c.  of  vaccine  will  contain  the  number  of 
organisms  constituting  the  proper  maximum  dose;  when  less  than  the 
maximum  dose  is  desired,  it  can  readily  be  measured  by  employing  a 
graduated  hypodermic  syringe. 

The  Opsonins  and  Opsonic  Index. — Metchnikoff  demonstrated  the 
phenomenon  of  phagocytosis,  ascribing  to  the  leukocytes,  notably  the 
polymorphonuclear,    and   certain   other   tissue   cells,   the   function   of 


^  Equation  for  estiiuatiug  number  of  bacteria  per  cubic  centimeter  of  suspension: 

E  :  B  :  :  E'  :  X 

E  =  number  of  erytln-ocytes  per  microscopic  field. 

B  =  number  of  bacteria  per  microscopic  field. 

E'=  number  of  erythrocytes  per  cubic  centimeter  of  blood. 

X  =  number  of  bacteria  per  cubic  centimeter  of  suspension. 

Example:  In  100  microscopic  fields  of  slide  there  were  counted  SOO  bacteria 
and  400  erythrocytes.  The  number  of  bacteria  per  field  =  8  and  of  erythrocytes  4; 
1  c.c.  of  blood  contains  5,000,000,000  erythrocytes.  The  number  of  bacteria  per 
cubic  centimeter  of  suspension  =  10, 000, 000, 000. 

4:8:  :  5,000,000,000  :  X  =  10,000,000,000. 

2  Formula  for  dilution  of  vaccine: 

S 

1  =Q. 

V 

S  =  number  of  killed  bacteria  in  suspensioa. 

V  =  number  of  killed  bacteria  desired  in  vaccine. 

Q   =  number  of  volumes  of  salt  solution  require<l  to  |)roduce  desired  dilution. 

Example:  Suspension  contains  10,000,000,000  bacteria  \>eT  cubic  centimeter; 
a  vaccine  containing  2")0,000,()00  is  desired. 

10,000,000,000  -=-  2r)0,000,0()()  =  40—1  =  30  volumes  of  salt  .solution  to  be 
added  to  1  volume  of  su.spension. 


VACCINE   THKRAl'Y  OF  ORAL  INFECTIONS  513 

(Migulfiiig  and  digrsting  ])actoria.     lie  advanced  the  pliagoeytic  theory 
of  immunity. 

This  attracted  the  attention  of  scientists  for  a  number  of  years, 
but  ^^•as  practically  lost  sight  of  by  the  majority  following  the  pro- 
mulgation of  Ehrlichs  theory;  a  few,  however,  still  occupiefl  them- 
sehes  with  researches  on  phagocytosis,  and,  among  other  facts,  it  was 
demonstrated  that  when  the  leukocytes  were  freed  from  serum  they  lost 
the  function  of  phagocyting  the  majority  of  species  of  bacteria,  but  when 
serum  was  added  this  function  again  became  manifest.  This  demon- 
strated thef act  that  scrum  was  necessary  for  the  phagocytic  phenomenon, 
and  it  was  claimed  by  some  that  serum  stimulated  the  leukocytes  to 
exert  this  function.  It  remained  for  Wright  to  demonstrate  that  when 
leukocytes  washed  in  sodium-citrate-chlorid  solution,  for  the  purpose 
of  freeing  them  from  serum,  were  brought  in  association  with  bacteria 
that  had  pre\'iously  been  treated  with  serum,  the  phagocytic  phenome- 
non again  became  manifest,  thus  proving  conclusively  that  the  serum 
element  necessary  for  phagocytosis  acted  not,  as  was  supposed,  on  the 
leukocytes,  but  upon  the  bacteria,  preparing  them  for  the  engulfing 
function  of  the  phagocytes.  To  these  substances  Wright  gave  the  name 
of  opsonins. 

The  opsinins  may  be  defined  as  vital  tissue  elements,  circulating  in 
the  body  fluids,  having  the  property  of  acting  upon  bacteria,  so  as  to 
prepare  them  for  phagocytosis.  These  elements  exist  normally  in  the 
tissues  (normal  opsonins),  and  act  as  one  of  the  normal  defences  against 
the  invasion  of  the  tissues  by  bacteria;  they  are  decreased  by  many 
factors  exerting  a  deleterious  influence  on  the  normal  metabolic  processes 
of  the  economy,  rendering  the  individual  more  susceptible  to  infection; 
they  are  likewise  decreased  in  certain  infections,  and  can  be  markedly 
increased  by  active  immunization  (immune  opsonins)  by  means  of  the 
bacterial  vaccines. 

The  fact  must  be  borne  in  mind,  that  while  immunity  against  certain 
species  of  bacteria  is  apparently  wholly  opsonic,  in  the  case  of  other 
species  it  is  not  only  opsonic,  but  there  are  other  elements,  as  agglu- 
tinins, bacteriolysins,  and  antitoxins,  exerting  an  antibacterial  function; 
further,  that  there  is  no  evidence  of  opsonic  immunity  in  connection 
with  protection  against  certain  other  species  of  bacteria.  The  opsonic 
index  is  the  opsonizing  power  of  a  given  serum  as  compared  with 
that  of  one  or  more  normal  sera  taken  as  a  unit.  This  index  guides 
the  operator  as  regards  the  amount  of  vaccine  to  be  employed  as  the 
initial  dose,  and  the  intrespacing  and  increasing  of  subsequent  doses. 

The  greater  the  depression  of  the  opsonins  the  smaller  should  be  the 
33 


514 


1'  YORlillEA   AL  \  EOLA HIS 


initial  (lose  of  vaccine,  and  the  more  carefully  should  the  following 
doses  be  increased  and  intersj)aced. 

To  illustrate  this,  let  us  consider  the  phenomena  presentinj^  in  a 
case  of  infection  not  only  as  it  appears  for  treatment,  but  following  the 
injection  of  vaccine.  An  index  determination  will  show  a  greater  or 
lesser  depression  of  the  ojisonins  toward  the  organism  concerned  in  the 
mfection;  following  the  injection  of  a  vaccine  there  a]){)cars  after  from 
six  to  twenty-four  or  forty-eight  hours  a  fiu-ther  dei)ressi()n  of  the  opson- 
ins, which  condition  is  termed  the  negative  phase;  later,  if  the  dose 
has  not  been  too  large,  or  the  resistance  of  the  individual  too  low,  we 
will  find  a  rise  in  the  opsonins  to  or  above  that  exhibited  before  inocula- 
tion, this  is  termed  the  positive  phase;  a  second  inoculation  should  not 
be  made  until  the  establishment  of  this  phase;  when  a  second  dose  of 
vaccine  will  give  rise  to  a  less  marked  negative  phase  followed  by  a 
more  pronounced  positive  phase;  these  phases  present  in  order  following 
subsequent  inoculations  until  tlie  index  rises  to  or  above  normal,  i.  e., 
when  the  opsonizing  power  of  the  patient's  serum  equals  or  exceeds 
that  of  the  normal  controls.  The  rapidity  with  which  this  condition 
is  established  depends  on: 

The  Type  of  Infection;  Degree  of  Depression  of  Opsonins;  General  Con- 
dition of  the  Patient  and  the  Care  Exercised  as  Regards  the  Dosage  and 
Interspacing  of  the  Vaccine. 

Fig.  567 


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Chart  showing  effect  of  inoculations  in  a  case  of  streptococcous  infection  of  the  nasal  sinus.  Note 
negative  and  positive  phases  following  the  injection  of  vaccine,  beginning  with  10,000,000  and  in- 
creasing to  100.000,000.     Circles  indicate  the  index. 

Technique  of  Determining  the  Opsonic  Index. — Apparatus  required: 
An  opsonizer:  This  consists  of  a  copper  box,  with  two  openings  in 
the  top,  for  a  thermoregulator  and  a  thermometer.  Through  this  box 
are  soldered  horizontally  brass  tubes,  f  inch  inside  diameter;  the  size 


VACCINE  THERAPY  OF  ORAL  INFECTIONS  515 

of  opsouizer  and  number  of  tubes  can  be  varied  to  suit  the  require- 
ments of  tlie  operator.  A  high-speed  centrifuge,  fitted  with  small  tubes 
for  washing  the  blood  and  separating  leukocytes.  A  small  mechanical 
shaker  will  be  found  a  very  convenient  part  of  the  outfit.  Wright's 
capillary  pipettes,  made  of  yV  to  i  inch  glass  tubing;  pieces  of  the  tubing 
about  6  inches  long  are  heated  in  the  middle  by  means  of  a  Bunsen  or 
blast  flame  and  drawn  out  to  a  diameter  of  about  -3V  inch;  the  distal 
end  is  fitted  with  a  small  rubber  bulb.  Serum  pipettes,  for  collecting 
and  separating  the  serum;  these  are  about  22  inches  long,  of  thin  glass 
tubing,  one  end  drawn  out  straight,  the  other  drawn  out  and  bent  at 
an  angle  of  45  degrees.  Other  apparatus  required  include  a  microscope; 
microscope  slides  and  cover-glasses;  a  blood  stylet;  sterile  bottles, 
tubes,  and  glass  pearls;  sterile  volumetric  and  capacity  pipettes. 

Reagents  required  include  0.85  per  cent,  sodium  chlorid  solution, 
a  1  per  cent,  sodium  citrate  solution  in  0.85  per  cent,  sodium  chlorid 
and  suitable  bacterial  and  blood  stains. 

Further,  we  require  a  bacterial  emulsion,  washed  leukocytes,  serum 
from  patient;  normal  sera,  preferably  from  three  or  four  normal  indi- 
viduals; if  the  serum  of  but  one  healthy  person  is  used  it  should  be  com- 
pared every  few  days  with  several  other  normal  sera,  and  if  more  than 
a  very  slight  variation  is  noted,  the  several  sera  employed. 

The  bacterial  emulsion  is  prepared  by  cultivating  the  organism  on 
suitable  media  for  eighteen  to  twenty-four  hours;  washing  it  off  with 
sterile  salt  solution;  emulsifying  in  a  sterile  bottle  or  tube  containing 
glass  pearls;  some  bacteria  are  readily  emulsified  wdien  shaken  by  hand, 
while  others  must  be  placed  in  a  shaking  apparatus,  the  latter  procedure 
being  preferable  in  all  cases.  After  emulsifying  and  diluting  the  sus- 
pension, it  is  centrifugalized  for  one  or  two  minutes,  to  remove  any 
clumps  that  may  remain.  The  density  is  then  determined  by  opsonizing 
with  normal  serum  to  obtain  its  so-called  phagocyting  index,  or  by  com- 
paring it  with  a  barium  sulfate  standard  (McFarland's  nephelometer), 
and  then  diluted  to  the  proper  strength ;  it  is  stated  that  it  should  be  of 
such  density  that  when  opsonized  with  normal  scrum  each  leukocyte 
will  ingest  from  five  to  eight  of  the  ordinary  bacteria.  Some  prefer  a 
suspension  of  somewhat  greater  strength;  the  counts  are  more  difficult, 
but  the  results  are,  it  is  claimed,  more  uniform. 

Washed  leukocytes  are  obtained  by  filling  two  of  the  small  centrifuge 
tubes  three-quarters  full  of  citrate  solution;  then  wrapping  the  finger 
with  a  rubber  band,  so  as  to  cause  congestion  at  the  end,  make  a  punc- 
ture with  a  stylet  at  the  root  of  nail  or  side  of  finger,  and  allow  the  blood 
to  fill  the  citrate  tubes.     It  is  then  mixed  by  inverting  tubes  several 


510  PYORRHEA    AJA'KOLARIS 

times,  and  centrifuj^alized ;  when  the  corpuscles  are  well  packed  and  the 
su{)ernatant  fluid  is  clear,  remove  the  solution  carefully,  so  as  not  to 
disturb  the  corpuscles,  fill  with  0.85  per  cent,  sodium  chlorid  solution, 
and  R^a'm  centrifugalize.  It  is  best  to  repeat  the  latter  process  twice 
to  make  sure  that  all  of  citrate  and  serum  has  been  washed  out;  remove 
the  salt  solution  carefully,  to  avoid  disturbing  the  layer  of  leukocytes 
which  will  have  collected  on  the  surface  of  the  sediment;  the  last  drops 
are  best  remoA'cd  by  inclining  the  tube  and  inserting  a  capillary 
pipette  at  the  ui)per  part  of  the  meniscus.  The  upper  layer  of  sediment, 
containing  the  leukocytes,  is  removed  with  a  clean  capillary  pipette  and 
placed  in  a  small  sterile  tube.  This  is  then  thoroughly  mixed  by  drawing 
in  and  out  of  the  pipette,  being  careful  to  avoid  admixing  air  bubbles. 
This  so-called  leukocyte  cream  will  contain  with  the  leukocytes  some 
eiythrocytes.  These  appear  to  be  advantageous,  as  better  results  are 
obtained  when  they  are  present  than  when  leukocytes  alone,  the  true 
leukocyte  cream,  are  employed. 

Serum  is  obtained  by  puncturing  the  finger,  and  allowing  blood  to 
flow  into  the  curved  end  of  the  blood  pipette  until  a  sufficient  quantity 
is  obtained;  the  tube  is  then  grasped  lengthwise  between  the  thumb  and 
forefinger  and  the  point  of  the  straight  end  warmed  and  sealed  in  the 
flame.  As  the  end  of  the  tube  cools  the  blood  in  the  curved  end  is  drawn 
into  the  body.  The  tube  can  be  placed  in  the  opsonizer  or  incubator  for 
fifteen  to  twenty  minutes,  when  the  serum  will  usually  be  separated; 
if  not,  the  tubes  may  be  centrifugalizcd  for  a  few  moments.  When  the 
serum  is  required,  the  tubes  may  be  notclied  on  one  side  with  a  file  and 
readily  snapped  off  with  the  fingers  or  by  touching  with  a  hot  glass  point. 

Method  of  Determining  Index. — The  opsonizer  should  be  placed  on  a 
table  to  the  right  or  left  of  the  operator;  sera,  leukocyte  cream,  bacterial 
suspension,  and  all  necessary  apparatus  in  front;  all  within  reach,  as  one 
must  work  quickly  and  accurately,  and  each  tube  be  timed  as  it  is 
placed  in  the  opsonizer.  A  mark  is  made  with  a  paraffin  pencil  on  the 
capillary  pipette,  three-quarters  of  an  inch  from  the  end;  the  rubber 
bulb  is  connected  and  the  mixture  made  by  drawing  substances  into 
the  tube  in  the  following  order:  1  volume  of  leukocytes,  a  bubble  of  air, 
1  volume  of  bacterial  suspension,  a  second  bubble  of  air,  1  volume  of 
serum — some  add  to  this  a  second  volume  of  leukoc^les,  varying  the 
technique  in  this  respect,  with  excellent  results.  The  writer  has  found 
this  of  value  especially  when  the  stronger  bacterial  suspension  is  em- 
ployed. The  contents  of  the  pipette  is  then  emptied  into  the  con- 
cavity of  a  concave  slide  and  thoroughly  mixed  by  drawing  in  and  out  of 
the  pipette  several  times,  care  being  taken  to  get  rid  of  all  air  bubbles, 


VACCIXE  THERAPY  OF  ORAL  INFECTIONS  517 

as  this  interferes  to  some  extent  with  phagocytosis;  the  mixture  is 
drawn  into  the  pipette,  the  end  sealed  quickly,  and  placed  in  the  opson- 
izer,  where  it  is  left  for  exactly  fifteen  minutes;  some  incubate  for  twenty 
minutes — this  makes  little  or  no  difference.  The  important  point  to 
bear  in  mind  is  that  all  tubes,  the  preparations  to  be  tested  and  controls, 
must  be  opsonized  for  the  same  length  of  time,  as  a  matter  of  a  few 
seconds  frequently  makes  more  difference  in  the  results  than  one 
would  imagine.  The  point  of  pipette  is  then  broken  off  and  the  contents 
expressed  on  one  end  of  two  or  three  clean  glass  slides  and  spread  e^'enly 
over  the  surface  by  placing  the  end  of  another  slide  in  contact  with  the 
drop  and  drawing  it  over  the  first;  this,  if  properly  done,  yields  a  thin 
even  smear.  Some  employ  a  specially  made  spreader,  but  this  will  be 
found  unnecessary,  as  one  can  make  perfect  smears  with  a  little  practice 
by  using  the  end  of  an  ordinary  slide.  The  preparation  is  allowed  to 
dry  in  the  air,  and  stained  with  Wright's  or  some  other  blood-stain;  if 
one  should  employ  the  ordinary  aqueous  staining  solutions,  the  prepara- 
tion must  be  first  fixed  by  treating  for  a  minute  with  methyl  alcohol. 
The  technique  for  staining  is  the  same  as  for  ordinary  blood  films  with 
which  anyone  who  will  undertake  the  work  is  familiar. 

The  number  of  bacteria  ingested  by  two  hundred  leukocytes  are 
counted  in  each  preparation,  i.  e.,  those  made  "^ath  patient's  and  normal 
sera  used  as  a  unit.  Some  investigators  pool  the  normal  sera  and  make 
but  one  unit  preparation;  tliis  is  not  a  good  practice,  as  the  pooled 
sera  preparations  frequently  vary  quite  markedly  from  those  made 
with  each  serum  separately.  After  counts  are  made,  divide  the  number 
of  bacteria  ingested  per  leukocyte  (phagoc}i:ing  index)  in  the  prepara- 
tions made  with  patient's  seriim,  by  the  number  ingested  per  leukocyte 
in  those  made  with  the  normal  sera,  wdiich  gives  the  opsonic  index. 

Many  wall  meet  difficulties  in  making  these  preparations.  One  great 
source  of  trouble  to  beginners  is  controlling  the  pipette  so  as  to  obtain 
exact  amounts  of  each  ingredient  in  making  the  mixture.  Accuracy 
can  only  be  attained  by  practice.  The  pipette  can  be  handled  best  by 
grasping  between  the  middle  and  third  finger,  and  the  bulb  between 
the  thumb  and  index  finger. 

Method  of  Making  Inoculation. — After  having  decided  on  the  dosage 
of  vaccine  to  be  employed,  a  1  to  2  c.c.  hypodermic  syringe,  having  a 
glass  barrel  and  fitted  with  a  needle  of  comparatively  small  lumen, 
is  carefully  sterilized  and  filled  with  the  vaccine.  The  skin  over  the 
site  chosen  for  inoculation  is  cleansed  with  a  2  per  cent,  phenol  solution, 
followed  by  sterile  water  and  absolute  alcohol,  and  the  needle  intro- 
duced into  the  subcutaneous  tissue.    The  site  of  inoculation  is  preferably 


51S  I'YORRIIKA    ALVEOLA RIS 

just  below  the  angle  of  the  scapula,  outer  side  of  upper  arm,  the  buttocks, 
thii!:h,  or  outer  side  of  the  leg. 

The  dose  of  vaccine  to  be  given  varies  according  to  the  organism 
employed;  tlie  degree  of  depression  of  index;  the  t\})e  of  infection;  age 
and  physical  condition  of  the  patient.  In  many  instances  the  dose 
employed  has  been  too  large  and  some  of  the  poor  results  reported  are 
undoubtedly  due  to  this  fact;  it  is  always  best  to  start  with  a  small 
dose  and  increase.  No  absolute  rules  can  be  laid  down  regarding  the 
size  of  the  dose;  in  general  it  can  be  said  that  smaller  doses  should  be 
employed  when  the  index  is  very  low  than  when  moderately  depressed ; 
in  general,  if  employed  at  all,  than  in  local  infections;  in  acute  than  in 
chronic  conditions;  in  children  and  individuals  markedly  depressed  and 
in  poor  condition  than  in  adults  and  the  more  robust.  The  doses  of  the 
various  vaccines  that  will  commonly  be  employed  in  treating  infections 
of  the  oral  cavity  range  about  as  follows: 

^Micrococcus  aureus  and  albus,  oO,0()0,0()(),  1()0,(){)(),()()0  to 
600,000,000. 

Streptococcus  pyogenes,  10,000,000,  25,000,000  to  100,000,000. 

Pneumococcus,  10,000,000,  25,000,000  to  100,000,000. 

Micrococcus  catarrhalis,  25,000,000,  to  100,000,000. 

Influenza  bacillus,  25,000,000  to  100,000,000. 


CHAPTER    XVI 

DISCOLORKl)  TEETH  AND  THEIR  TREATMENT 

By  EDWARD  C.  KIRK,  D.D.S.,  Sc.D. 

Discoloration  of  a  tooth  is  a  result  of  death  of  its  pulp. 
While  death  of  the  pulp  does  not  always  or  necessarily  involve  dis- 
coloration of  the  tooth  structures,  yet  when  the  condition  does  exist  the 
general  cause  is  as  stated.  Reference  is  here  made  to  a  progressive 
interstitial  staining  of  the  entire  dentin  structure,  and  is  exclusive 
of  certain  metallic  stains,  also  of  localized  stains  resulting  from  the 
imbibition  of  pigmentary  matters  occasionally  observed  where  small 
areas  of  dentin  have  become  denuded  of  enamel  covering,  or  where 
the  latter  has  been  so  imperfectly  formed  as  to  afford  an  insufficient 
barrier  to  the  ingress  of  pigmentary  matters  from  the  food  or  oral 
secretions. 

Three  classes  of  conditions  are  presented  for  consideration  and  treat- 
ment: First,  cases  where  discoloration  has  resulted  from  death  of  the 
pulp  due  to  causes  other  than  its  exposure;  second,  discoloration  from 
pulp  death  consequent  upon  exposure;  and  third,  special  discolorations 
due  to  adventitious  causes  superadded  to  the  conditions  affecting  the 
cases  included  in  the  foregoing  second  division. 

Any  of  the  numerous  traumatic  causes  which  bring  about  death  of 
the  pulp,  e.  g.,  blows,  sudden  contact  with  hard  substances,  biting 
threads,  violent  thermal  shocks,  the  injudicious  application  of  continuous 
force  in  regulating,  or  the  application  of  arsenous  oxid  to  the  dentin, 
where  no  exposure  or  only  minute  exposure  of  the  pulp  exists,  may 
produce  hyperemia  and  congestion  of  the  pulp,  or  strangulation 
of  its  circulatory  system,  the  formation  of  emboli,  thrombus,  hemor- 
rhagic infarct,  etc.,  leading  to  a  breaking  down  of  the  corpuscular 
elements  of  the  blood,  the  escape  of  hemoglobin  from  the  stroma 
of  the  red  corpuscles,  its  solution  in  the  blood  plasma,  and  resulting 
infiltration  of  the  tubular  structure  of  the  dentin  by  the  hemoglobin 
solution,  giving  the  tooth  a  distinctly  pinkish  hue  when  examined  by 
direct  or  transillumination. 

Suffusion  of  the  dentin  structure  by  discharged  hemoglobin  may  be 
readily  produced  by  the  topical  application  to  the  exposed  pulp  of 
medicaments  having  a  hemolytic  property,  for  example,  trinitro- 
glycerin,  glonoin,  as  an  ingredient  of  a  cocain  solution  intended  for 
the  production  of  local  anesthesia,  will  not  infrequently  produce  hemo- 

(519) 


520  DISCOLORED  TEETH  AND  TlIEIIi  TREAT M EXT 

lysis  with  suffusion  of  tlie  dentin  when  the  mixture  is  locally  aj^plied 
to  a  bleeding  pulp.  Even  distilled  water  exerts  a  hemolytic  effect, 
rupturing  the  stroma  of  erythrocytes  by  endosmosis;  therefore,  all 
solutions  intended  for  topical  a])plication  to  a  bleeding  pulp  should  be 
at  least  isotonic  with  the  plasma  or  preferably  of  greater  density  in  order 
to  avoid  staining  the  dentin  with  diffused  hemoglobin. 

Teeth  so  affected  rapidly  change  in  color  through  various  gradations 
in  tint  from  the  original  pinkish  hue,  which  becomes  yellow;  this,  grow- 
ing darker,  passes  into  brown,  and  after  the  lapse  of  considerable  time 
the  tooth  may  become  a  permanent  slaty  gray  or  black. 

The  violence  of  the  hyperemia  preceding  the  death  and  disintegration 
of  the  pulp  in  a  considerable  degree  determines  the  rapidity  of  the 
process  of  subsequent  tooth  discoloration.  When  congestion  of  the 
pulp  has  been  relati\ely  slight  and  the  necrotic  process  has  proceeded 
slowly,  the  sudden  infiltration  of  the  dentin  with  hemoglobin  does  not 
occur,  consequently  the  initial  change  in  color  following  complete  death 
of  the  pulp  may  be  so  slight  as  to  escape  detection  except  upon  most 
searching  examination  with  special  means  of  illumination,  and  even 
then'  may  be  manifested  only  by  a  slight  diminution  in  the  normal 
translucency  of  the  tooth  as  compared  with  adjoining  teeth.  Such  teeth, 
however,  if  permitted  to  remain  untreated,  eventually  grow  darker, 
and  while  they  may  not  acquire  a  degree  of  discoloration  equal  to  those 
which  have  suffered  sudden  and  violent  death  of  the  pulp,  still  they 
become  so  unsightly  as  to  demand  treatment  for  the  restoration  of 
their  normal  color. 

The  Rationale  of  the  Process  of  Discoloration. — In  teeth  discolored  as 
a  consequence  of  the  death  of  the  pulp  without  its  exposure — viz., 
those  of  the  first  class — it  is  evident  that  the  sourc(\s  of  ])igmentation 
are  internal  to  the  tooth  and  are  to  be  st)ught  for  solely  in  the  products 
of  decomposition  of  the  elements  of  the  pulp  tissue  and  of  its  vascular 
supply. 

The  proteid  elements  of  the  pulp  tissue  are  complex  combinations 
of  carbon,  oxygen,  hydrogen,  nitrogen,  sulfur,  and  phosphorus,  which 
in  their  gradual  breaking  down  by  the  process  of  putrefactive  decom- 
position are  split  up  finally  into  carbon  dioxid,  water,  ammonia,  and 
hydrogen  sulfid,  with  possibly  the  formation  of  traces  of  phosphatic 
salts.  The  group  of  substances  entering  into  the  composition  of  the 
histological  elements  of  pulp  tissue  contains  no  constituents  which  in 
the  progressive  changes  resulting  from  putrefactive  decomposition 
should  form  compounds  likely  to  cause  permanent  discoloration  of 
the  tooth  structures. 

When,  how^ever,  the  vascular  supply  is  considered  as  a  factor,  the 
explanation  of  the  cause  of  discoloration  in  the  cases  in  question  becomes 
reasonably  clear.  The  red  blood  corpuscles  contain  as  their  charac- 
teristic component  hemoglobin  or  oxyhemoglobin  according  as  the  blood 


THE  RATIONALE  OF  THE  PROCESS  OF  DISCOLORATION      521 

is  venous  or  arterial,  and  this  substance  is  its  essential  coloring  ingre- 
dient. When  undergoing  gradual  decomposition,  hemoglobin  passes 
through  a  variety  of  alterations  in  its  chemical  constitution,  accompanied 
by  a  corresponding  series  of  color  changes. 

A  familiar  illustration  of  these  color  changes  is  furnished  by  the 
cycle  of  color  alterations  witnessed  in  a  bruise.  Immediately  following 
an  injury  to  the  flesh,  of  the  character  alluded  to,  an  extravasation  of 
blood  in  the  bruised  territory  occurs,  causing  undue  reddening  of  the 
skin;  this  is  soon  followed  by  an  increasing  darkening  of  the  tissue, 
until  there  results  what  is  popularly  termed  a  "  black-and-blue  spot." 
Further  decomposition  of  the  coloring  matter  of  the  extravasated  blood 
induces  a  variety  of  color  changes  ranging  through  the  scale  of  yellows 
and  browns,  until  the  pigmentary  matter  is  finally  removed  by  absorp- 
tion through  the  capillary  bloodvessel  system  of  the  part. 

In  passing  through  the  cycle  of  color  changes  due  to  its  progressive 
decomposition,  hemoglobin  undergoes  several  alterations  in  composi- 
tion, among  which  are  formed  a  number  of  definite  compounds,  each 
having  marked  chromogenic  features.  Of  these  decomposition  products, 
methemoglobin  (brownish  red),  hemin  (bluish  black),  hematin  (dark 
brown  or  bluish  black),  and  hematoidin  (orange),  are  the  most  im- 
portant and  best  known.  While  the  gradual  decomposition  of  the  color- 
ing matter  of  the  blood  here  noted  may  and  doubtless  does  account 
for  certain  phases  of  tooth  discoloration,  other  factors  which  exert  a  pro- 
foundly modifying  influence  upon  the  process  are  yet  to  be  considered. 

The  putrefactive  decomposition  of  the  proteid  elements  of  the  pulp 
results,  as  before  stated,  in  the  production  of  hydrogen  sulfid  in  con- 
siderable quantity.  The  albumins  contain  from  0.8  to  2.2  per  cent,  of 
sulfur  (Hammersten),  which  in  the  splitting  up  of  the  compound  during 
putrefaction  yields  a  large  amount  of  hydrogen  sulfid.  In  pulp  decom- 
position this  hydrogen  sulfid  is  generated  in  contact  with  the  hemo- 
globin, and  necessarily  exerts  a  marked  modifying  action  upon  the  de- 
composition process  of  that  substance.  Miller  says:  "If  a  current  of 
hydrogen  sulfid  is  conducted  through  fresh  blood  or  a  solution  of 
oxyhemoglobin  in  the  presence  of  air  or  oxygen,  sulfomethemoglobin 
is  formed,  which  is  greenish  red  in  concentrated  solutions  and  green  in 
dilute  solutions.  If  we  lay  a  freshly  extracted  tooth  in  a  mixture  of 
meat  and  saliva  so  that  a  part  of  the  enamel  surface  remains  free,  and 
moisten  the  surface  with  blood,  it  will  take  on  a  dirty  green  color  if  kept 
at  blood  temperature  in  an  absolutely  moist  condition  for  from  twenty- 
four  to  forty-eight  hours.  It  is  quite  possible  that  the  dirty  green 
deposits  which  form  in  putrid  conditions  of  the  mouth,  in  stomatitis 
mercurialis,  scorbutica,  gangrenosa,  etc.,  or  even  in  inflammatory  con- 
ditions of  less  importance,  as  well  as  in  cases  of  absolute  neglect  of  the 
care  of  the  mouth,  may  owe  their  green  color  to  the  presence  of 
sulfomethemoglobin." 


522  DISCOLORED  TEETH  AXD  THEIR   TREATMENT 

As  in  pulp  decomposition  hydroj^en  sulfid  is  being  formed  in  the 
presence  of  hemoglobin,  this  fact  warrants  the  belief  that  a  combina- 
tion takes  place  resulting  in  the  formation  of  this  same  compound, 
which  Miller  regards  as  productive  of  certain  stains  upon  the  external 
surface  of  the  teeth. 

The  slaty  gray  or  bluish  pigmentation  always  noticeable  upon  the 
visceral  walls  and  frequently  beneath  the  skin  of  animal  bodies  under- 
going putrefactive  decomposition  is  a  familiar  example  of  the  action  of 
hydrogen  sulfid  or  its  ammonia  combinations  upon  decomposing  hemo- 
globin in  hemorrhagic  extravasations,  and  is  a  process  and  form  of  pig- 
mentation exactly  analogous  to  that  which  is  here  described  as  taking 
place  in  the  dentinal  structure  from  putrefacti\-e  decomposition  of  the 
pulp.  "When  red  corpuscles  are  just  beginning  to  disintegrate,  the 
coloring  matter  formed  is  hemoglobin;  but  the  yellow  and  brown 
granular  masses  fou'id  in  cells  and  lying  free  in  tissues  are,  as  a  rule, 
derivatives  of  hemoglobin,  not  hemoglobin  itself.  These  derivatives 
are  di\ided  into  two  groups  according  as  they  contain  iron  or  not,  the 
former  being  called  hemosiderin,  the  latter  hematoidin."^  "  When  acted 
upon  by  ammoniimi  sulfid  (a  derivative  of  putrefacti\e  decomposition 
of  albumin),  hemosiderin  becomes  black,  iron  sulfid  being  formed. "- 
Grohe^  believes  that  as  a  result  of  putrefaction  iron  is  liberated  from  its 
compound  with  hemoglobin,  so  that  when  thus  freed  it  readily  combines 
with  the  hydrogen  sulfid. 

Iron  is  the  most  important  element  to  be  considered  in  the  list  of 
factors  causing  the  discoloration  of  this  group  of  cases.  It  is  the  iron 
constituent  of  the  red  corpuscles  which  is  the  essential  chromogenic 
factor  from  first  to  last  in  their  cycle  of  color  changes. 

The  process  of  putrefactive  decomposition  consists  of  a  series  of 
chemical  changes  wrought  out  through  the  agency  of  microorganisms, 
involving  the  breaking  down  by  successive  stages  of  highly  complex 
organic  compounds  and  their  resolution  into  compounds  of  much  sim- 
pler constitution.  It  is  not  known  to  what  extent  this  splitting  up  of 
the  components  of  the  pulp  and  its  vascular  elements  is  ultimately  car- 
ried in  the  series  of  changes  resulting  in  the  permanent  discoloration 
of  the  tooth.  From  what  is  known  of  the  ultimate  composition  of  the 
compounds  involved  it  may,  however,  be  safely  inferred  that,  reduced 
to  its  lowest  terms,  the  result,  so  far  as  pigmentation  is  concerned,  would 
be  the  formation  of  iron  sulfid,  the  elements  of  which,  with  the  exception 
of  some  unimportant  alkaline  and  earthy  salts,  are  the  only  ones 
entering  into  the  original  compounds  which  are  fixed  and  therefore 
capable  of  forming  a  stable  residuum  in  the  tubular  structure  of  the 
dentin.  While  iron  sulfid  as  such  cannot  be  held  wholly  accountable 
for  the  final  bluish-black  color  of  a  tooth  which  has  reached  the  stage 

'  Ziegler,  General  Pathology,  1S9.5.         ^  Ibid.         ^  Virchow's  Archiv,  Band  x\-. 


DISCOLORATION  OF  TEETH  FOLLOWING  DEATH  OF  PULP     523 

of  permanent  discoloration,  the  pif^nientation  is  almost  certainly  due 
either  to  it  or  to  some  allied  compound  in  which  iron  and  sulfur,  with 
some  or<2;anic  constituents,  largely  enter,  and  which  by  a  further  slight 
decomposition  would  >'ield  true  iron  sulfid. 

The  significance  and  importance  of  a  recognition  of  the  possible 
presence  of  the  iron  compound  as  a  factor  in  tooth  discoloration  is 
further  brought  out  in  the  study  of  bleaching  methods. 

Discoloration  of  Teeth  following  Death  of  the  Pulp  Consequent  upon  its 
Exposure. — When  death  and  decomposition  of  the  pulp  are  consequent 
upon  exposure  of  that  organ,  through  caries  or  otherwise,  to  the  irrita- 
tive influences  of  infective  agents  present  in  the  oral  secretions  and 
food,  or  to  thermal  shock,  etc.,  the  putrefactive  process  involving  the 
pulp  tissues  is  modified  in  character  and  rapidity  to  a  degree  which 
may  affect  the  character  of  the  resulting  discoloration.  Thus,  the 
yellowish  or  brownish  discoloration  so  often  seen  in  teeth  whose  pulps 
have  been  devitalized  through  systemic  or  traumatic  causes,  and  which 
in  many  cases  appears  to  be  more  or  less  permanent  in  character,  is 
rarely  observed  in  those  teeth  whose  pulps  have  been  devitalized  through 
exposure  by  caries. 

In  these  latter  cases  the  original  suffusion  of  the  dentin  by  hemo- 
globin has  ordinarily  not  taken  place  and,  moreover,  the  progress  of  the 
putrefactive  process  is  comparatively  rapid,  the  conditions  being  more 
favorable,  so  that  the  coloring  matter  of  the  blood  is  sooner  reduced  to 
its  lowest  terms  in  the  scale  of  decomposition  products,  i.  e.,  to  the  slaty 
blue  or  black  pigmentation  before  noted.  The  pigmentation  of  the 
dentin  in  cases  of  pulp  exposure  with  subsequent  decomposition  of  that 
organ  is  due  to  the  diffusion  of  some  of  the  decomposition  products 
of  hemoglobin  that  have  been  formed  in  the  pulp  chamber  and  not  in 
the  tubuli  as  in  the  class  of  cases  first  considered.  In  addition  to  the 
increased  rapidity  of  putrefactive  decomposition  incident  to  cases  of  dis- 
coloration following  pulp  exposure,  another  and  important  modifying 
factor  in  the  process  of  discoloration  is  the  ingress  afforded  to  the  oral 
fluids,  food  materials,  and  other  adventitious  substances  which  find 
their  way  into  the  mouth,  and  ultimately,  through  the  open  cavity  of 
the  tooth,  to  its  pulp  canal,  and  thence  to  the  tubular  structure  of 
the  dentin.  These  extraneous  substances,  in  the  course  of  time, 
may  infiltrate  the  tooth  structure,  and  while  no  especially  noticeable 
or  characteristic  effect  may  be  observed  so  far  as  color  is  concerned, 
yet  they  frequently  exert  an  influence  upon  the  coloration  of  the  tooth 
which  so  alters  its  character  as  to  render  successful  bleaching  treatment 
extremely  difficult  and  a  resort  to  special  methods  or  a  variety  of 
methods  necessary. 

The  introduction  of  fatty  or  oily  substances  or  of  astringent  and 
coagulant  matters,  for  example,  may  act  upon  the  coloring  matter  in 
such  a  way  as  to   "set"  it  permanently  in  the  same  manner  that 


524  DISCOLORED  TEETH  AXD  THEIIi  TREATMEXT 

mordants  form  iiisolul^le  compounds  or  lakes  with  the  dyestuffs  used 
in  the  d\eing  of  textile  faljries. 

Another  and  important  class  of  substances  which  frequently  are  the 
cause  of  staining  of  the  tooth  structure  are  metallic  salts  which  are  used 
in  dental  therapeutic  treatment  or  are  accidentally  formed  during  the 
application  of  corrosive  medicaments  to  the  teeth,  through  the  action  of 
such  remedies  upon  fillings  in  situ  or  upon  the  instruments  by  which 
the  applications  are  made.  For  example,  the  use  of  iodin  or  sulfuric 
acid  or  other  metallic  solvents  in  connection  with  steel  instruments 
and  the  subsequent  use  of  medicaments  containing  tannin  as  an 
ingredient. 

The  treatment  of  these  conditions  will  be  separately  considered. 

Teeth  Suitable  for  the  Bleaching  Operation. — In  deciding  upon  the 
advisability  of  attempting  tiie  bleaching  operation  in  any  gi\en  case, 
the  general  conditions  which  determine  the  judgment  of  the  operator 
with  respect  to  all  dental  operations  should  govern  his  course. 

As  all  therapeutic  and  restorative  measures  in  dentistry  are  a  series 
of  compromises  with  disease  conditions  or  their  sequelae,  it  is  the  duty 
of  the  operator  under  all  circumstances  to  capitulate  upon  the  basis  of 
greatest  achantage  to  the  patient.  Therefore,  if  discoloration  of  a  tooth 
is  practically  the  only  factor  in  the  problem  presented  by  a  given  case, 
the  effort  should  be  made  to  restore  the  organ  to  its  normal  condition 
of  color.  The  same  rule  should  be  applied  to  all  cases  of  discolored 
teeth  in  which  structural  loss  by  caries  or  fracture  has  not  been  so  great 
as  to  preclude  a  satisfactory  restoration  by  proper  filling  or  rei)lace- 
ment  of  the  lost  structure  by  a  porcelain  inlay.  The  cases  in  which  it 
is  not  advisable  to  attempt  a  bleaching  operation  are  only  those  in  which 
loss  of  structure  is  so  extensive  as  to  require  a  crowning  operation. 

In  the  judgment  of  many  operators  it  is  considered  useless  to  attempt 
the  bleaching  of  any  teeth  excepting  the  incisors,  because  of  the  diffi- 
culty and  length  of  time  frequently  required  for  the  successful  bleaching 
of  canines,  bicuspids,  and  molars,  owing  to  the  thickness  of  their  walls 
and  the  consequent  depth  of  the  structure  requiring  treatment.  It  is 
also  held  to  be  useless  to  attempt  the  bleaching  of  teeth  which  have 
been  discolored  by  metallic  stains  throughout  their  structure.  The 
fallacy  of  such  a  view  is  self-evident  when  it  is  considered  that  if  any 
portion  of  the^  dentinal  structure  of  a  discolored  tooth  is  amenable  to 
the  bleaching  treatment,  its  complete  restoration  is  simply  a  question  of 
continuance  or  repetition  of  the  operation  until  the  desired  end  is 
attained. 

With  regard  to  discoloration  by  metallic  stains,  while  teeth  so  affected 
present  problems  of  great  complexity,  and  require  not  only  special 
study  but  the  application  of  special  methods  of  treatment  based  upon 
proper  recognition  of  the  chemical  relationships  involved  between 
the  nature  of  the  stain  and  that  of  the  agent  used  for  its  removal,  the 


NATURE  OF  PROBLEM  INVOLVED  IN  TOOTH  BLEACHING     525 

attempt  should  be  made  in  justice  to  the  patient,  e\'en  though  ultimate 
failure  result,  in  order  that  the  necessity  for  destruction  of  the  natural 
crown  for  the  purpose  of  its  replacement  by  an  artificial  substitute  may, 
if  possible,  be  postponed  for  as  long  a  period  as  may  be  attainable. 

Nature  of  the  Problem  Involved  in  Tooth  Bleaching. — The  bleaching 
process  is  dependent  upon  a  chemical  reaction  between  a  compound 
having  color  and  some  substance  capable  of  so  affecting  its  compo- 
sition that  the  color  is  discharged,  or,  in  other  words,  of  so  affecting 
the  integrity  of  the  color  molecule  as  to  destroy  its  identity,  which 
results  in  a  loss  of  its  distinguishing  characteristic,  viz.,  its  color. 

The  substances  concerned  in  discoloration  of  tooth  structure,  as  has 
been  previously  shown,  are  derived  from  the  pulp  and  its  vascular 
elements  and  the  organic  contents  of  the  tubular  structure  of  the  den- 
tin, through  the  gradual  putrefactive  processes  which  become  operative 
subsequent  to  the  death  of  the  pulp.  These  pigmentary  products  of 
pulp  decomposition  we  know  to  be  organic  in  character;  and  further, 
that  they  exhibit  the  property  of  color  by  virtue  of  definite  conditions 
of  molecular  composition — that  is  to  say,  a  certain  arrangement  of  a 
definite  kind  and  number  of  atoms  has  resulted  in  the  formation  of  a 
molecule  having  its  individual  group  of  chemical  and  physical  prop- 
erties, among  which  latter  is  a  characteristic  color. 

Whatever  brings  about  an  alteration  in  the  composition  of  the  mole- 
cule at  once  destroys  the  identity  of  the  matter  so  treated.  Hence,  if 
we  can  act  upon  the  coloring  matter  wdiich  gives  rise  to  the  staining  of 
a  tooth  by  means  of  an  agent  capable  of  effecting  an  alteration  in  the 
atomic  arrangement  of  composition  of  the  color  molecule,  we  may  expect 
incidentally  to  remove  or  discharge  its  color  feature. 

Two  general  classes  of  substances  have  been  successfully  used  as 
bleaching  agents:  First,  those  which  act  by  virtue  of  their  power  to 
evolve  oxygen  in  the  active  or  nascent  condition,  and  known  as  oxidiz- 
ing agents;  second,  those  which  act  in  an  opposite  manner  by  virtue 
of  their  strong  affinity  for  oxygen,  and  which  are  called  reducing  agents. 
The  oxidizing  bleachers  destroy  the  identity  of  the  color  molecule  by 
seizing  upon  its  hydrogen  element  to  form  water.  The  reducing  agents 
act  by  removing  the  oxygen  atom  from  the  color  molecule  to  form 
by-products  depending  upon  the  character  of  the  reducing  agent  used. 

Chlorin  and  its  cogeners  iodin  and  bromin  act  as  indirect  oxidizing 
bleachers;  the  dioxids  of  hydrogen  and  of  sodium  are  direct  oxidizers. 
Potassium  permanganate  may  also  be  classed  with  this  group,  although 
its  successful  use  as  a  bleaching  agent  depends  upon  a  subsequent  treat- 
ment of  the  substance  to  be  bleached  with  some  solvent  capable  of 
removing  the  manganese  dioxid  formed  as  a  by-product  of  the  action  of 
the  permanganate.  It  has  somewhat  extensive  and  satisfactory  use  as 
an  agent  for  bleaching  sponges,  and  has  been  used  for  bleaching  teeth, 
but  is  of  greatly  inferior  value  to  other  agents  for  the  latter  use. 


526  DISCOLORED  TEETH  AX D  THEIR  TREATMENT 

The  only  agent  beloiigiiifi:  to  the  group  of  reducinfj  bleachers  whieh 
has  thus  far  been  found  avaihil)le  for  bleaehhig  teeth  is  sulfur  dioxid, 
either  in  the  gaseous  condition  or  in  aqueous  solution. 

Chlorin  as  a  Bleacher. — The  general  use  of  chlorin  as  a  bleaehing 
agent  in  the  arts  no  doubt  suggested  its  use  in  the  treatment  of  tooth 
discoloration.  Its  introduction  as  a  tooth-bleaching  agent,  as  well  as  the 
assembling  of  the  general  principles  of  its  use  for  tooth  bleaehing  into  a 
coordinated  system,  are  due  to  Dr.  James  Truman,  whose  method  depends 
upon  the  liberation  of  chlorin  from  calcium  hypochlorite,  commonly 
called  bleaching  powder  or  "chlorinated  lime,"  in  the  pulp  chamber  and 
cavity  of  decay  in  the  tooth.  Chlorin  is  liberated  from  the  bleaching  pow- 
der by  the  action  of  dilute  acetic  acid;  this  taking  place  in  contact  with 
the  discolored  structure  it  is  rapidly  bleached  as  a  result  of  the  action  of 
the  chlorin  upon  the  coloring  matter  contained  in  the  dentinal  tubules. 
Numerous  modifications  of  this  original  method  of  bleaching  tooth 
structure  have  been  suggested,  but,  as  the  ultimate  result  in  each  is 
accomplished  through  the  activity  of  chlorin,  a  rational  understanding 
of  the  mode  of  action  of  chlorin  in  this  relation  is  of  importance  as  an  aid 
to  the  intelligent  use  of  those  methods  for  tooth-bleaching  which  are 
dependent  upon  or  owe  their  efficacy  to  that  agent. 

Chlorin  is  an  elementary  gaseous  body,  greenish  in  color,  soluble  in 
water,  having  a  disagreeable  odor,  intensely  irritating  to  the  air  passages 
when  inhaled,  and  poisonous  when  breathed  in  sufficient  quantit}'.  It 
has  a  strong  affinity  for  all  metallic  bodies,  entering  into  direct  com- 
bination with  a  number  of  them,  under  fa\oral)le  circumstances,  with 
great  energy — forming,  as  a  rule,  compounds  that  are  soluble  in  water. 

One  of  its  distinguishing  features,  and  one  which  is  directly  concerned 
in  its  use  as  a  bleaching  agent,  is  its  strong  affinity  for  hydrogen.  So 
strong  is  this  affinity,  that  when  a  molecule  of  chlorin  is  brought  into 
contact  with  a  molecule  of  water  under  favorable  conditions,  the  hydro- 
gen of  the  water  molecule  is  seized  upon  by  the  chlorin  to  form  chlor- 
hydric  acid,  and  the  oxygen  is  set  free  in  the  nascent  state,  a  condition 
under  which  its  oxidizing  powers  are  exhibited  in  their  greatest  intensity. 
This  powerful  affinity  of  chlorin  for  hydrogen  enables  it  to  decompose 
many  other  hydrogen-containing  molecules  in  a  similar  manner,  form- 
ing chlorhydric  acid  and  destroying  the  identity  of  the  matter  acted 
upon. 

It  has  been  shown  that  all  organic  compounds  which  are  the  products 
of  the  vital  processes  of  the  animal  body  contain  hydrogen  as  an  impor- 
tant constituent.  This  applies  also  to  the  decomposition  products 
whose  presence  in  the  tubular  structure  of  the  dentin  is  the  cause  of 
tooth  discoloration. 

These  organic  stains  exliibit  the  property  of  color  by  virtue  of  certain 
definite  conditions  of  molecular  composition;  hence,  if  chlorin  is  caused 
to  act  upon  the  coloring  matter  which  causes  the  staining  of  a  tooth, 


PREPARATION  OF  TOOTH  FOR  OPERATION  OF  BLEACHING      527 

by  seizing  upon  and  combining  with  the  hydrogen  of  the  organic  pig- 
ment, the  identity  of  the  compound  as  such  is  destroyed,  and  its  char- 
acteristic feature,  that  of  color,  is  lost. 

The  principle  here  outlined  is  in\'olved  in  what  is  termed  the  direct 
action  of  chlorin  in  bleaching.  There  is,  however,  another  method  by 
which  chlorin  is  believed  to  act  as  a  bleacher  in  which  its  function  is 
indirect. 

In  some  cases  it  has  been  observed  that  chlorin  fails  to  act  except 
in  the  presence  of  moisture,  and  the  ratiunaJe  of  this  is  that  the  bleach- 
ing under  such  conditions  is  effected  by  nascent  oxygen  liberated  from 
the  water  molecule  when  the  chlorin  combines  with  its  hydrogen 
to  form  chlorhydric  acid;  thus:  Clj  +  HjO  =  2HC1  +  O.  That  such 
is  the  nature  of  the  process  in  many  cases  is  a  reasonable  deduction 
from  the  behavior  of  chlorin  under  analogous  conditions  when  it  acts 
indirectly  as  an  oxidizing  agent. 

Whatever  may  be  the  exact  nature  of  its  ultimate  action,  it  is  to  be 
borne  in  mind  that  its  bleaching  effect  is  due  solely  to  the  alteration 
which  it  makes  in  the  composition  of  the  color  molecule,  and  that  it 
has  no  soh'ent  power  whatever  on  the  organic  matter  upon  which  it 
acts.  It  changes  its  characteristics,  but  does  not  remove  it  by  solution. 
It  should  be  also  noted  in  this  connection  that  the  chlorin  compounds 
of  most  of  the  metallic  elements,  especially  when  in  dilute  solution,  are 
almost  colorless  as  compared  with  many  of  the  other  metallic  com- 
pounds— the  oxids  and  sulfids,  for  example.  Hence  it  is  that  when 
stains  owe  their  color  to  the  presence  of  certain  organic  compounds 
with  some  of  the  metals,  or  even  when  the  coloration  is  due  to  decom- 
position products  of  hemoglobin,  the  color  may  readily  be  discharged 
by  chlorin ;  but  if  the  iron  chlorid  thus  produced  by  the  action  of  chlorin 
on  the  iron  constituent  of  the  hemoglobin  remains  in  the  tooth 
structure  it  is  gradually  decomposed  and  new  combinations  of  it  are 
liable  to  occur,  which  result  in  a  return  of  the  discoloration. 

All  tooth-bleaching  methods  should  aim  not  only  to  discharge  the 
color  by  suitable  chemical  means,  but  should  go  farther  than  this,  and, 
as  far  as  it  may  be  possible  to  do  so,  remove  all  organic  debris  and 
by-products  of  the  bleaching  process  from  the  tubules,  for  as  long  as 
any  remain  the  tendency  to  a  return  of  the  discoloration  is  always  a 
possible  and  indeed  probable  menace  to  the  complete  and  permanent 
success  of  the  operation. 

When  the  tubular  contents  cannot  be  successfully  removed,  the 
tendency  to  a  return  of  discoloration  may  be  combated  by  hermetically 
sealing  the  tubular  orifices  with  an  impermeable  resinous  varnish  or  by 
permanently  coagulating  them.  This  feature  is  described  more  fully  in 
relation  to  the  details  of  the  bleaching  procedure. 

Preparation  of  the  Tooth  for  the  Operation  of  Bleaching. — Certain  general 
details  are  necessary  to  be  observed  in  the  preparation  of  teeth  for  the 


528  DISCOLORED   TEETH  AND  TIlElli   TREATMENT 

blciU'hinc:  operation,  whatever  may  be  the  method  of  treatment 
enij)l()y('(l. 

Appropriate  treatment  for  the  remoxal  of  all  septic  matter  from  the 
pulp  chamber  and  canal,  and  for  the  relief  of  any  existing  condition  of 
irritation  of  the  pericemental  membrane  and  tissues  of  the  apical  region, 
should  have  been  carried  out  and  the  tooth  brought  to  the  condition  in 
which  permanent  closure  of  the  apical  foramen  of  the  root  may  be  safely 
performed. 

The  rul)ber  dam  should  be  adjusted  with  special  care  and  only 
include  the  tooth  to  be  bleached.  If  two  adjoining  teeth  are  to  be 
bleached,  they  may  both  be  isolated  by  the  dam;  but  in  no  case  should 
one  or  more  adjacent  normal  teeth  be  included  with  the  tooth  to  be 
bleached.  While  the  inclusion  of  teeth  adjacent  to  the  one  which  is 
the  subject  of  any  ordinary  dental  operation  is  in  all  cases  desirable, 
there  are  good  reasons  why  such  a  plan  should  not  be  pursued  in  the 
bleaching  procedure.  The  chemicals  used  for  the  purposes  may  possibly 
have  some  disintegrating  or  solvent  action  upon  the  enamel  structure, 
and  such  action,  should  it  occur,  should  be  confined  strictly  to  the  tooth 
undergoing  treatment  and  held  within  the  limits  of  safety  by  close 
observation  and  appropriate  treatment,  which  conditions  cannot  be  as 
thoroughly  controlled  and  the  process  as  satisfactorily  managed  w4ien 
several  teeth  are  included  within  the  territory  of  operation. 

Furthermore,  as  nearly  all  of  the  bleaching  agents  used  or  those 
which  are  employed  as  adjuvants  to  the  process  have  a  more  or  less 
irritative  or  escharotic  efi'ect  upon  the  soft  tissues  of  the  mouth,  extra 
precautions  must  be  taken,  in  adjusting  the  dam,  against  leakage  at  its 
attachment  to  the  cervix  of  the  tooth.  As  the  chances  of  leakage  are 
greatly  multiplied  when  several  holes  are  punched  in  the  dam  for  adjust- 
ment to  as  many  teeth,  it  is  for  this  reason  also  that  no  other  than  the 
tooth  to  be  treated  should  have  the  dam  adjusted  to  it. 

Supposing  the  tooth  to  be  an  upper  incisor,  the  dam  should  be  slii)ped 
over  it  and  the  margin  of  rubber  encircling  the  cervix  should  be  gently 
carried  under  the  free  margin  of  the  gum  either  by  means  of  a  small 
flat  burnisher  of  suitable  angle  and  curvature,  or  by  means  of  a  waxed 
floss-silk  thread.  One  or  two  turns  of  a  ligature  should  then  be  thrown 
around  the  cervix  below  the  dam  to  hold  it  securely  in  place.  The 
dam  may  be  fixed  with  greater  security,  especially  as  against  any 
accidental  traction  made  upon  it  during  the  operation,  by  fastening  it 
with  a  ligature  made  as  follows  and  thrown  around  its  cervix: 

A  piece  of  waxed  ligature  silk  about  eighteen  inches  in  length  has 
a  large  knot  tied  at  about  its  middle  portion  by  making  six  or  eight 
turns  of  the  thread  loosely  around  the  end  of  the  index  finger  of  the 
left  hand.  Upon  withdrawing  the  finger  a  series  of  loops  are  had  through 
which  one  of  the  free  ends  of  the  thread  is  now  passed,  as  in  making 
the  first  half  of  a  flat  knot,  as  illustrated  in  Fig.  568.    By  drawing  upon 


PREPARATION  OF  TOOTH  FOR  OPERATION  OF  BLEACHING      529 

the  free  ends  of  the  thread  until  all  of  the  loops  are  closed  upon  them- 
selves, a  hard  knot  of  more  or  less  spheroidal  shape  is  formed  about 
midway  between  the  ends  of  the  ligature.  The  ligature  so  prepared 
is  placed  around  the  tooth  in  such  a  manner  that  the  knot  as  described 
shall  be  located  upon  and  at  the  middle  portion  of  the  palatal  cervical 
margin.  A  half-knot  is  then  made  by  tying  the  ligature  in  front  so  that 
it  shall  rest  directly  opposite  the  palatal  knot,  viz.,  at  the  middle  portion 
of  the  labial  cervical  margin.  The  ligature  is  drawn  into  fairly  close 
contact  with  the  tooth,  and,  with  both  ends  held  firmly  in  the  left 
hand  and  drawn  somewhat  tense,  the  portion  encircling  the  tooth  is 
firmly  but  gently  forced  up  against  the  rubber  dam  and  gingival  margin, 
the  ligature  at  the  same  time  being  drawn  tightly  until  the  anatomical 
constriction  of  the  tooth  at  its  cervix  will  serve  to  hold  it  from  slipping 
downward,  especially  upon  the  palatal  aspect  of  the  tooth. 

Fig.  568 


When  the  ligature  is  found  to  be  securely  placed  as  described,  the 
knot  upon  the  labial  aspect  is  completed  and  further  enlarged  in  bulk 
by  re-tying  the  thread  four  or  five  times.  The  free  ends  of  the  ligature 
should  then  be  cut  off  close  to  the  knot.  As  an  additional  safeguard 
against  leakage  of  irritating  bleaching  agents  through  the  cervical 
attachment  of  the  dam,  and  out  upon  the  soft  tissues,  it  is  well  after 
making  the  tooth  perfectly  dry  to  paint  the  ligature  and  a  narrow  band 
of  its  adjacent  territory  with  chloropercha,  which  after  evaporation  of 
the  solvent  will  effectually  prevent  any  accident  from  leakage. 

The  placing  of  a  large  knot  upon  the  palatal  aspect  at  the  cervical 
margin  has  another  decided  advantage  in  that  it  not  only  holds  the  dam 
more  securely  against  slipping  downward,  but  holds  it  away  from  the 
palatal  surface,  which  is  ordinarily  the  point  of  entrance  to  the  pulp 
chamber  and  canals  in  these  cases.  The  point  of  canal  entrance  may, 
however,  be  through  a  proximal  cavity,  if  such  a  one  afford  sufficient 
access. 

The  canal  filling  in  all  cases  of  bleaching  without  exception  should 
be  gutta-percha.  No  other  material  used  for  canal  filling  possesses  the 
generally  desirable  qualities  needed  for  that  purpose  in  this  class  of 
cases.  The  extent  of  the  canal  filling  should  include  one-third,  or  at 
least  not  over  one-half,  of  the  distance  from  the  apex.  A  considerable 
portion  of  the  canal  beyond  the  level  of  the  gingival  margin  is  thus 
left  unfilled  in  order  that  the  coronal  end  of  the  root  may  be  bleached 
34 


530  DISCOLORED  TEETH  AND  TIIEIIi   TREATMENT 

as  well  as  the  tooth  crown.  This  is  especially  necessary  when  more 
or  less  recession  of  the  gum  from  its  normal  attachment  has  occurred, 
leaving  the  cervical  cementum  exposed  to  the  action  of  the  oral  fluids, 
food,  etc.,  which  have  a  tendency  to  cause  discoloration  of  the  exposed 
root  tissue. 

The  root  being  filled  as  directed,  all  fillings  wherever  existent  in  the 
tooth  should  be  removed.  This  is  a  ])reliminary  procedure  which 
should  not  be  omitted  in  any  case,  but  where  any  bleaching  method  is 
used  which  involves  the  employment  of  chlorin  as  the  active  agent  it 
becomes  imperatively  necessary  for  reasons  which  are  explained  in 
connection  with  the  description  of  the  chlorin  methods.  Aside  from 
other  considerations,  the  removal  of  all  fillings  preparatory  to  the 
bleaching  operation  has  a  decided  value  in  facilitating  the  process  by 
exposing  an  increased  area  of  the  dentinal  structure  and  thereby  permit- 
ting the  action  of  the  bleaching  agent  over  a  larger  territory  of  ingress. 

When  all  fillings  or  softened  tooth  structure  have  been  removed,  as 
well  as  all  septic  and  extraneous  matter  of  whatever  character,  by 
mechanical  process,  the  tooth  should  be  washed  thoroughly  with  dilute 
ammonia  water,  or  better  with  a  hot  solution  of  borax  in  distilled  water 
in  the  proportion  of  5  j  to  f  o  j.  The  object  of  this  treatment  is  to  remove 
by  saponification  and  solution  all  fatty  matters  which  may  obstruct 
the  ingress  of  the  bleaching  agent  into  the  dentinal  structure. 

In  nearly  all  cases  where  discoloration  has  occurred  from  a  decom- 
posed pulp,  and  where  the  canals  and  pulp  chamber  have  been  left 
untreated,  there  will  be  observed,  on  opening  into  such  a  pulp  chamber 
for  the  first  time,  a  dark  layer  of  oily  or  greasy  material  lining  its  walls. 
The  thorough  removal  of  this  dark  layer  should  be  effected  prior  to 
an>'  attempt  at  bleaching,  as  it  appears  to  prevent  the  ingress  of  the 
bleaching  agent  into  the  dentinal  structure.  The  most  satisfactory 
method  for  removing  the  dark  greasy  layer  is  by  the  use  of  suitable 
instruments — either  properly  shaped  spoon  or  hoe  excavators  or  round 
burs  in  the  engine.  The  thorough  removal  of  this  layer  necessitates 
free  access  to  the  pulp  chamber,  which  should  be,  as  a  general  rule, 
obtained  b>'  means  of  an  ample  opening  upon  the  lingual  aspect  of 
the  tooth  in  the  case  of  incisors,  and  through  the  morsal  surface  in 
bicuspids,  etc. 

Having  by  mechanical  means  and  through  the  agency  of  borax  or 
ammonia  and  hot  distilled  water  effected  a  thorough  cleansing  of  the 
interior  portion  of  the  tooth,  it  should  next  be  dried  to  the  extent  of 
having  all  superfluous  moisture  removed,  and  it  will  then  be  in  condi- 
tion for  the  application  of  whatever  method  of  bleaching  may  be  chosen 
for  the  particular  case  in  hand.  When  sodium  dioxid  or  Schreier's 
kalium-natrium  with  hydrogen  dioxid  are  to  be  used  as  the  bleaching 
agents  the  preliminary  saponification  of  the  canal  contents  with 
ammonia  or  hot  borax  solution  becomes  unnecessary. 


TRUMAN'S  METHOD  531 

Truman's  Method. — Tliis,  as  before  stated,  was  the  first  method 
successfully  employed  for  bleaching  teeth.  It  consists  in  liberating 
chlorin  from  ordinary  chlorinated  lime  by  means  of  a  weak  acid  in 
the  pulp  ciiamber  of  the  tooth.  Any  acid  will  effect  the  liberation  of 
chlorine  from  the  bleaching  powder,  but  acetic,  tartaric,  or  oxalic  are 
generally  used.  Care  must  be  observed  in  selecting  a  good  quality  of 
bleaching  powder,  as  that  substance  rapidly  undergoes  decomposition 
spontaneously,  especially  in  a  moist  atmosphere.  Good  chlorinated  lime 
is  a  dry  powder  having  a  strong  odor  of  chlorin.  If  it  is  moist  or  pasty, 
and  has  but  a  feeble  odor,  it  should  be  rejected  as  worthless.  Brands 
of  bleaching  powder  dispensed  in  metallic  packages  should  not  be  used, 
as  they  are  invariably  contaminated  with  metallic  chlorids  due  to  the 
slow  action  of  the  contents  upon  the  containing  package.  This  is  par- 
ticularly the  case  when  sheetiron  boxes  are  used.  The  return  of  dis- 
coloration in  many  cases  after  bleaching  by  the  Truman  method  is 
undoubtedly  due  to  the  use  of  bleaching  powder  so  contaminated. 
The  powder  dispensed  in  glass  bottles  or  in  paraffined  paper  cartons 
is  more  reliable. 

Its  application  to  the  tooth  may  be  effected  in  several  ways : 

(a)  By  packing  the  dry  powder  in  the  pulp  chamber  and  then  moist- 
ening the  latter  with  the  acid. 

(b)  By  mixing  the  powder  with  sufficient  distilled  water  to  make  a 
coherent  mass  which  is  more  easily  manipulated,  then  packing  it  in  the 
pulp  chamber  and  applying  the  acid. 

(c)  By  first  moistening  the  interior  of  the  tooth  with  the  acid,  next 
dipping  the  instrument  into  the  powder  and  then  into  the  acid,  each 
time  carrying  the  mixed  materials  into  the  tooth  until  the  desired 
change  of  color  is  produced. 

Probably  the  most  satisfactory  method  is  to  pack  the  dry  powder 
into  the  tooth  and  apply  the  acid  to  it,  after  which  immediately  seal  the 
cavity  with  a  single  pellet  of  gutta-percha.  By  using  a  50  per  cent, 
solution  of  acetic  acid  the  evolution  of  chlorin  will  take  place  with  a 
satisfactory  degree  of  uniformity,  and  not  so  rapidly  as  to  interfere  with 
its  penetration  throughout  the  discolored  tubular  structure  of  the  dentin. 
The  bleaching  mass  may  be  sealed  in  place  by  means  of  zinc  oxyphos- 
phate  if  desired,  but  it  is  usually  unnecessary  to  use  anything  other 
than  gutta-percha  or  one  of  the  soft  temporary  stopping  materials  for 
this  purpose. 

The  case  may  be  dismissed  for  one  or  two  days  and  the  treatment  as 
outlined  repeated  at  similar  intervals  until  the  tooth  is  restored  to 
normal  color. 

The  instruments  used  in  connection  with  this  process  should  be  of 
vulcanite,  bone,  ivory,  or  wood.  Upon  no  consideration  should  steel, 
gold,  or  platinum  instruments  be  used,  as  chlorin  acts  directly  upon 
each  of  these  metals,  forming  soluble  chlorids,  which  if  carried  into  the 


532  DISCOLORED  TEETH  AND  THEIR  TREATMENT 

tooth  striK'ture  will  give  rise  to  a  permanent  staining  of  most  intract- 
able character.  The  only  metals  which  may  be  safely  used  in  connec- 
tion with  any  chlorin  process  of  bleaching  are  zinc  and  aluminum, 
the  chlorids  of  which  are  colorless,  but,  nevertheless,  they  are  objection- 
able for  the  reason  that  both  are  coagulant  and  color  mordants. 
Aluminum  instruments  for  the  purpose  may  be  quickly  improvised  out 
of  wire  or  heavy  plate.  Gold  instruments  have  been  recommended, 
but  they  are  open  to  the  very  grave  objection  of  forming  a  chlorid  by 
direct  combination  with  chlorin,  which  salt  is  one  of  the  most  important 
staining  media  known  to  the  histologist;  as  a  matter  of  fact,  the  writer 
has  seen  several  cases  where  a  permanent  purj)le  staining  of  the  tooth 
has  resulted  from  neglect  to  remove  gold  fillings  before  applying  the 
chlorin  method  of  bleaching,  and  there  is  certainly  no  reason  why  the 
same  result  should  not  follow  the  using  of  gold  instruments  in  the  same 
connection. 

When  the  tooth  has  been  restored  to  its  proper  color  it  should  be 
thoroughly  washed  with  liberal  quantities  of  very  hot  distilled  water, 
dried  out  with  bibulous  paper,  and  thoroughly  desiccated  with  a  current 
of  dry  hot  air,  after  which  the  canals,  pulp  chamber,  and  cavities 
should  be  filled  with  zinc  oxychlorid. 

The  final  filling  of  the  cavities  of  entrance  and  of  decay  should  be 
postponed  until,  by  a  lapse  of  considerable  time,  the  permanence  of  the 
operation  has  been  established.  This  probationary  period  may  with 
advantage  be  prolonged  to  four  or  six  months. 

The  final  washing  of  the  tooth  with  hot  distilled  water  previous  to 
the  insertion  of  the  zinc  oxychlorid  filling  is  a  feature  of  the  opera- 
tion which  requires  special  care  and  attention.  As  left  after  the  appli- 
cation of  the  bleaching  agent,  the  pulp  chamber  and  canals  and  denti- 
nal structure  are  filled  with  free  chlorin  in  solution,  iron  chlorid  from 
the  combination  of  the  chlorin  w^ith  the  iron  element  of  the  color  mole- 
cule, calcium  acetate,  or  other  salt  of  calcium,  depending  upon  the 
nature  of  the  acid  used  in  the  process,  and  probably  some  undecom- 
posed  bleaching  powder.  These  substances  should  be  thoroughly 
removed  by  the  hot-water  douche.  At  least  a  pint  of  water  should  be 
strongly  injected  into  the  interior  of  the  tooth,  by  means  of  a  large  bulb 
syringe  or  other  convenient  means,  before  the  dam  is  removed,  A  thick 
towel  held  in  close  proximity  to  the  tooth  will  catch  the  water  as  it 
returns  from  the  tooth  and  protect  the  clothing  of  the  patient.  Distilled 
water  should  in  all  cases  be  used  for  this  irrigating  douche,  as  river 
water  and  many  other  specimens  of  water  from  natural  sources  contain 
iron  in  solution,  which  could  readily  become  a  contaminating  factor, 
leading  to  subsequent  return  of  discoloration. 

Zinc  oxychlorid  is  selected  as  the  permanent  filling  for  the  pulp 
chamber,  for  the  reason  that  it  is  necessary  so  to  act  upon  the  bleached 
organic  residuum  in  the  tubular  structure  as  to  j)re vent  any  alteration 


WRIGHT'S  METHOD  5:^3 

of  its  character  which  may  result  in  the  production  of  a  subsequent 
coloration.  Zinc  chlorid  possesses  the  projierty  of  convertinjT  many 
organic  substances  into  unalterable  compounds  by  its  coagulant  action, 
thus  tanning  or  mummifying  animal  tissue  and  preser\ing  it  indefi- 
nitel\'.  A  mass  of  zinc  oxy chlorid,  before  it  sets — i.  e.,  before  chemical 
combination  takes  place  between  the  zinc  oxid  powder  and  the  zinc 
chlorid  liquid,  is  functionally  free  zinc  chlorid — and,  as  a  matter  of 
fact,  the  properties  of  zinc  chlorid  are  manifested  by  such  a  mass  for  a 
considerable  period  of  time  after  the  mass  has  apparently  set.  When 
introduced  into  the  pulp  chamber  and  canal,  its  action  upon  the  organic 
debris  in  the  tubuli  is  as  stated,  and  the  material,  if  the  operation  has 
been  successfully  performed,  is  effectually  prevented  from  further  alter- 
ation, upon  which  condition  the  permanence  of  the  operation  depends. 

Another  method  for  preventing  subsequent  alteration  of  the  bleached 
organic  debris  in  the  tubular  structure  is  to  desiccate  the  tooth  thor- 
oughly by  means  of  the  hot-air  blast  and  saturate  the  dentin  with  some 
insoluble  resinous  varnish,  such  as  copal  ether  varnish,  or,  what  is  still 
better,  the  solution  of  trinitrocellnlose  in  methyl  alcohol  and  amyl 
acetate,  known  in  commerce  as  "kristaline,"  or  at  the  dental  depots  as 
"cavitine."  The  pulp  chamber  and  canals  may  then  be  filled  with  any 
suitable  filling. 

As  between  the  zinc  oxychlorid  filling  and  the  varnish  lining,  the 
choice  in  general  should  be  of  the  former.  The  .varnish  lining  is  adapt- 
able more  especially  to  cases  of  long  standing,  where  complete  liquefac- 
tion of  the  tubular  contents  has  left  them  practically  empty,  and  where, 
as  a  consequence,  there  is  nothing  upon  which  zinc  chlorid  can  exert  its 
coagulating  effect. 

Other  Chlorin  Methods. — The  solution  of  chlorinated  soda  known 
as  Labarraque's  solution,  or  Liquor  sodse  chloratse  U.  S.  P.,  may  be 
applied  to  the  pre^•iously  desiccated  tooth  structure  until  the  dentin 
is  saturated  with  the  solution,  after  which  an  application  of  a  dilute 
acid  is  made  which  liberates  chlorin.  The  chemical  principles  involved 
are  exactly  analogous  to  those  upon  which  the  method  with  bleaching 
powder  depends,  the  only  difference  being  that  the  source  of  the  active 
agent,  chlorin,  is  in  one  case  its  calcium  compound,  which  is  a  dry 
powder,  and  in  the  second  case  the  analogous  soluble  sodium  compound 
of  chlorin  is  the  material  from  which  the  active  agent  is  evolved. 

The  precautions  necessary  to  be  observed  are  exactly  the  same  as 
those  required  in  Truman's  method,  already  described.  The  results 
obtained  by  this  process  are  not  as  thorough  or  as  satisfactory  as  by  the 
Truman  method. 

Chlorin  per  se  has  been  used  for  tooth  bleaching,  and  was  the  basis 
of  a  method  devised  by  Dr.  E.  P.  Wright,  of  Richmond,  Va. 

Wright's  Method. — This  involved  the  use  of  a  complicated  apparatus 
by  which  a  glass  vessel  of  about  a  half-liter  capacity,  and  filled  with 


5o4  DISCOLORED  TEETH  A.\D  THEIR  TREATMENT 

chlorin  previously  prepared  in  the  laboratory,  was  connected  by  means  of 
a  doubly  i)erforated  rubber  stopper  and  two  picres  of  rublx-r  tubinif  with 
a  glass  adai)ter,  around  the  ojH'n  end  of  which  was  tied  the  rubber  d;un 
encircling  the  tooth  to  be  operated  upon.  About  midway  of  the  length 
of  one  of  the  rubber  tubes  connecting  the  chlorin  reserxoir  with  the 
rubber  dam  was  interposed  an  ordinary  syringe  bulb,  so  arranged  with 
hard-rubber  valves  that  by  repeatedly  compressing  and  relaxing  it  the 
chlorin  would  be  drawn  from  the  ^eser^'oi^  and  injected  through  a  glass 
delivery  jet  into  the  pulp  chamber.  Return  of  the  gas  to  the  reserxoir 
was  provided  for  by  the  second  piece  of  rubber  tubing  first  alluded  to. 
In  this  way  a  continuous  jet  of  chlorin  was  thrown  into  and  about  the 
tooth,  which,  by  means  of  the  rubber  dam,  was  placed  in  a  close  cham- 
ber forming  a  part  of  the  apparatus;  none  of  the  gas  could  escape  into 
the  surrounding  atmosphere.  The  complexity  of  the  apparatus  was 
a  formidable  obstacle  to  the  general  use  of  the  method,  and  it  was 
abandoned,  though  the  results  were  in  many  cases  very  satisfactory. 

lodin. — Reference  has  previously  been  made  to  iodin  as  a  bleaching 
agent.  Its  chemical  action  is  quite  analogous  to  that  of  chlorin,  though 
less  energetic.  In  slight  discolorations,  however,  iodin  may  often  be 
used  to  considerable  advantage  by  simply  saturating  the  dentin  with  an 
alcoholic  solution  of  iodin — e.  g.,  the  official  7  per  cent,  tincture — until 
the  tooth  structure  is  stained  a  characteristic  yellow.  The  ca\'ity  is 
then  sealed  temporarily  with  a  gutta-percha  filling  and  the  case  dis- 
missed for  twenty -four  hours,  at  the  expiration  of  which  period  a  marked 
improvement  in  color  will  be  observed.  The  same  precautions  as  Mith 
the  use  of  chlorin  in  regard  to  the  removal  of  metallic  fillings  and  the 
avoidance  of  contact  with  metallic  instruments  is  necessary  in  the 
use  of  iodin  for  bleaching  purposes. 


THE  DIOXID  BLEACHING  METHODS 

Bleaching  by  Means  of  the  Dioxid  of  Hydrogen  and  of  Sodium. — The 
commercial  introduction  of  solutions  of  hydrogen  dioxid  marked  a 
new  era  in  the  operation  of  bleaching  discolored  teeth.  The  bleaching 
property  of  hydrogen  dioxid  had  been  known  to  chemists  for  many  years, 
but  the  application  of  this  property  to  tooth-bleaching  dates  from  the 
medicinal  use  of  hydrogen  dioxid  solutions  for  the  treatment  of  puru- 
lent conditions  of  the  pulp  canal  and  about  the  roots  of  teeth.  When 
applied  in  the  canals  of  discolored  and  infected  teeth  it  was  obser\ed 
that  a  noticeable  bleaching  of  the  discolored  structure  resulted.  The 
hint  thus  given  was  further  studied  until  it  was  found  that  under  proper 
conditions  the  whole  structure  of  a  discolored  tooth  might  be  success- 
fully restored  to  normal  color. 

The  earlier  preparations  were  found  to  be  lacking  in  strength;  aqueous 


THE  DIOXID  BLEACHING  METHODS  535 

solutions  containing  more  than  3  or  4  per  cent,  of  absolute  hydrogen 
dioxid  were  found  to  be  too  unstable  to  keep  for  any  length  of  time, 
and  hence  were  unreliable.  The  problem  of  securing  a  stable  high- 
percentage  solution  of  the  dioxid  was  solved  by  using  ether  as  a  men- 
struum, and  the  25  per  cent,  solution  of  hydrogen  dioxid,  sold  as 
"caustic  pyrozone,"  is  now  generally  used  when  hydrogen  dioxid  is 
employed  as  a  bleaching  agent  in  connection  with  discolored  tooth 
structure. 

Subsequent  to  the  introduction  of  the  pyrozone  preparations,  the 
firm  of  jNIerck  has  produced  a  100- volume  solution  of  hydrogen  dioxid 
under  the  trade  name  of  Perhydrol,  which  is  the  most  active  and  efficient 
of  the  hydrogen  dioxid  preparations  as  tooth -bleaching  agents. 

Hydrogen  dioxid,  HjOg,  belongs  to  the  class  of  "oxidizing  bleachers," 
and  owes  its  activity  in  this  respect  to  the  weak  state  of  chemical 
combination  in  which  one  of  its  atoms  of  oxygen  is  bound  to  the  water 
molecule.  Many  substances  serve  to  disrupt  the  compound  and  liber- 
ate one  of  its  oxygen  atoms.  In  contact  with  pus,  blood,  inspissated 
mucus,  albumin,  and  in  fact  almost  every  kind  of  dead  organic  matter, 
its  decomposition  takes  place,  evolving  oxygen  and  decomposing  the 
organic  matter  either  wholly  or  in  part.  Hydrogen  dioxid  does  not 
bleach  all  of  the  decomposition  products  of  hemoglobin  with  equal 
facility.  It  quickly  removes  the  pink  discoloration  following  the  initial 
extravasation  of  hemoglobin  into  the  dentin,  but  when  the  brown  stage 
has  been  reached,  indicative  of  the  formation  of  hematin,  its  action  is 
but  slight.  Later,  however,  it  bleaches  more  readily.  The  refractory 
nature  of  hematin  with  respect  to  hydrogen  dioxid  has  been  experimen- 
tally tested  upon  the  substance  out  of  the  mouth. 

It  is  important  to  note  that  all  acids  promptly  convert  hemoglobin 
into  hematin,  which  is  highly  resistant  to  the  action  of  hydrogen  dioxid; 
therefore,  whenever  hydrogen  dioxid  is  used  to  bleach  a  tooth  in  the 
primary  or  pivot  stage  of  discoloration  the  hydrogen  dioxid  should  be 
made  alkaline  with  sodium  carbonate  or  hydroxid  to  neutralize  at  least 
its  usual  slight  acidity,  otherwise  its  acid  content  will  act  upon  the 
hemoglobin,  converting  it  into  hematin,  and  thus  set  the  color  in  such 
a  way  as  to  be  invulnerable  to  the  action  of  the  hydrogen  dioxid. 

In  bleaching  discolored  teeth  with  hydrogen  dioxid,  perhydrol  or  the 
ethereal  25  per  cent,  solution  known  as  pyrozone  is  directly  applied  to 
the  internal  portions  of  the  tooth  upon  small  pledgets  of  cotton  or  cotton 
wisps  rolled  upon  a  fine  flexible  canal  instrument.  After  each  appli- 
cation the  menstruum  is  evaporated  by  blasts  of  warmed  air  from  a 
hot-air  syringe,  and  the  applications  similarly  made  are  repeated  until 
the  desired  effect  is  produced.  It  has  been  found  in  practice  that 
more  rapid  and  permanent  effects  are  produced  when  the  solution 
is  rendered  alkaline.  This  may  be  readily  done  by  the  addition  of  a 
few  drops  of  liquor  ammonise  fortior  or  by  a  solution  of  one  of  the 


536  DISCOLORED  TEETH  AND  TIIEIIi  TUEATMENT 

caustic  alkalies,  e.  g.,  sodium  or  potassium  iiydroxid  or  sodium  dioxid. 
A  very  satisfactory  method  of  securing  the  alkaline  effect  in  this  pro- 
cess is  that  suggested  hy  Dr.  I).  N.  McQuillen.  His  method  is  to 
first  treat  the  pulp  chamber  and  canals  with  applications  of  Schreier's 
Kalium-natrium  preparation,  and  after  the  de})ris  from  its  action  has 
been  mechanically  removed  with  instruments  and  cotton  twists,  with- 
out washing  the  canal,  an  application  of  {)yrozone  is  made.  The  bleach- 
ing action  follows  with  great  rapidity,  and  has  apparently  greater 
permanence  than  when  the  pyrozone  is  used  alone.  In  cases  in  which 
the  action  proceeds  very  slowly — for  example,  when  at  the  end  of  a  thirty 
miiuites'  continuous  treatment  the  bleaching  is  not  complete — it  is  well 
to  seal  an  application  of  pyrozone  upon  cotton  in  the  canal  and  allow  it 
to  remain  for  twenty-four  hours,  when  a  second  treatment  will  usually 
complete  the  operation. 

In  this,  as  in  all  bleaching  operations,  it  is  advisable  to  fill  the  tooth 
temporarily  with  some  easily  removable  filling  in  order  to  test  the  per- 
manence of  the  operation,  and  after  the  lapse  of  a  reasonable  time,  if 
there  is  no  tendency  to  a  return  of  the  discoloration,  the  canals  and 
ca\ity  may  be  permanently  filled. 

Harlan's  Method. — This  consists  in  acting  upon  hydrogen  dioxid  by 
aluminum  chlorid.  The  aluminum  salt  is  packed  in  the  cavity  and 
moistened  with  the  dioxid.  The  technique  of  the  Drocedure  is  the  same 
as  for  the  methods  already  described.  This  process  was  originally 
classified  with  the  chlorin  methods,  as  the  decomposition  was  supposed 
to  take  place  according  to  the  following  equation : 

Allele  +  3H2O2  =  AI2O3  +  3H:0  +  6C1. 

Experimental  study  of  the  reaction  between  aluminum  chlorid  and 
hydrogen  dioxid  by  the  writer  developed  the  fact  that  oxygen  and  no 
chlorin  was  given  off,  and  that  the  aluminum  chlorid  was  unaltered 
during  the  process.  Hence  it  was  discovered  that  the  reaction  was 
simply  due  to  a  catalytic  action  of  the  aluminum  salt  (a  property 
which  in  this  relation  it  shares  in  common  with  many  other  metallic 
salts),  whereby  nascent  oxygen  is  liberated  from  the  hydrogen  dioxid. 
The  process,  therefore,  has  no  greater  value  than  those  in  which  hydro- 
gen dioxid  is  directly  applied.  The  aluminum  chlorid,  being  an  active 
coagulant,  is  contraindicated  as  a  factor  in  the  bleaching  process  until 
a  point  had  been  reached  where  a  coagulant  is  needed  as  a  fixative  after 
the  bleaching  has  been  effected. 

The  Sodiiim  Dioxid  Method. — Sodium  dioxid,  NajO.,  is  the  chemical 
analogue  of  hydrogen  dioxid,  and  like  the  latter  is  characterized  by 
the  readiness  with  which  it  parts  with  its  atom  of  loosely  combined 
oxygen  under  similar  circumstances.  The  essential  difference  in  its 
properties  is  the  character  of  its  by-product  after  its  decomposition 


THE  DIOXID  BLE ACHING  METHODS  537 

has  taken  place.  Itself  a  strong  caustic  alkali,  it  still  retains  its  alka- 
line and  caustic  properties  after  the  loss  of  one  of  its  atoms  of  oxygen, 
becoming  Na./),  which  in  combination  with  water  is  ordinary  sodium 
hydroxid  or  caustic  soda.  This  substance,  as  well  as  the  sodium  dioxid, 
has  not  only  a  saponifying  property  for  all  of  the  vegetable  and  animal 
oils  and  fats,  but  also  a  solvent  action  upon  animal  tissue.  This  property 
is  of  great  value  in  removing  from  the  dentin  structure  all  of  the  con- 
tained organic  matter,  whether  normal  or  in  a  state  of  decomposition. 
Having  the  oxidizing  and  co^nsequently  the  bleaching  quality  in  addi- 
tion to  its  solvent  and  saponifying  properties,  it  is,  therefore,  one  of  the 
most  valuable  bleaching  and  detergent  agents  at  our  command.  The 
substance  is  dispensed  as  a  yellowish-white  powder  in  tin  cans  or  glass 
bottles  hermetically  sealed,  as  it  is  very  hygroscopic,  and  after  twenty- 
four  hours'  exposure  to  moist  air  absorbs  nearly  its  own  weight  of  water; 
it  also  loses  much  of  its  activity. 

For  use  as  a  bleaching  agent,  it  is  applied  to  the  dentin  in  saturated 
solution.  In  making  the  solution,  special  care  is  necessary  in  order  to 
avoid  elevation  of  temperature,  by  reason  of  the  energy  with  which  it 
enters  into  combination  with  the  water.  If  the  solution  is  allowed 
to  become  heated  in  the  making,  decomposition  of  the  compound  with 
loss  of  oxygen  occurs,  and  its  bleaching  power  is  destroyed.  The  solu- 
tion is  best  made  by  pouring  into  a  small  beaker,  of  about  one  ounce 
capacity,  about  two  drams  of  distilled  water,  and  immersing  the 
beaker  in  a  larger  vessel  or  dish  containing  iced  water  or  pounded  ice. 
The  can  containing  the  dioxid  powder  should  then  have  its  lid  per- 
forated with  a  number  of  small  holes  similar  to  the  lid  of  a  pepper 
shaker,  and  the  powder  be  slowly  dusted  into  the  distilled  water  in  the 
small  beaker;  or  the  powder  may  be  gradually  dropped  into  the  water 
by  tapping  it  from  the  point  of  a  knife  or  spatula.  The  powder  is 
added  to  the  water  until  the  solution  assumes  a  semi-opaque  appearance, 
indicating  the  point  of  saturation. 

On  removing  the  beaker  from  the  cooling  mixture,  the  dioxid  solution 
will  in  a  few  minutes  assume  a  transparent,  straw-colored  appearance 
and  is  ready  for  use. 

The  applications  are  to  be  made  similarly  to  the  hydrogen  dioxid 
applications,  but  upon  asbestos  fiber  instead  of  cotton,  as  the  latter  is 
acted  upon  by  the  sodium  dioxid  and  converted  into  a  glue-like  mate- 
rial, amyloid,  which  is  difficult  to  remove  and  interferes  with  the  suc- 
cess of  the  operation. 

After  the  dentin,  which  should  have  been  previously  desiccated,  is 
thoroughly  saturated  with  the  dioxid  solution,  an  application  of  10  per 
cent,  sulfuric  acid  should  be  made,  which  neutralizes  the  strong  alkali, 
forming  sodium  sulfate  and  hydrogen  dioxid,  thus: 

Na^Oa  +  H.SO4  =  Na,SO,  +  H,0,. 


538  DISCOLORED  TEETH  AX D  THEIR  TREATMENT 

The  reaction  is  usually  attended  with  some  effervescence,  which,  taking 
place  in  the  tubular  structure  of  the  dentin,  mechanically  forc-es  out  its 
contents  and  thus  exerts  a  detergent  action  upon  it.  The  tooth  should 
now  be  washed  with  hot  distilled  water  in  copious  quantity  and  the 
dioxid  application  repeated,  omitting  the  subsequent  treatment  with 
acid,  but  washing  again  thoroughly  with  the  hot  water. 

Sodium  dioxid  solution,  as  prepared  for  bleaching,  may  be  applied 
to  the  pulp  chamber  and  root  canal  without  the  preliminary  treatment 
required  where  other  bleaching  agents  are  employed.  It  is  without 
harmful  irritative  action  upon  the  apical  tissues  unless  used  in  excess 
or  forced  through  the  foramen  by  careless  manipulation.  It  is  a  power- 
ful germicide  and  disinfectant,  and  therefore  peculiarly  suited  to  the 
treatment  of  putrescent  cases,  which  by  its  action  are  rendered  sterile 
and  aseptic  as  well  as  bleached  at  one  operation.  Its  saponifying  and 
solvent  properties  completely  remove  the  greasy  dark  layer  of  decom- 
posed material  which  is  found  lining  the  pulp  chamber  and  canals 
alluded  to  on  page  530,  so  that  the  use  of  the  sodium  dioxid  method 
makes  unnecessary  the  application  of  borax  or  ammonia  for  its  removal 
as  a  preliminary.  When  used  for  its  sterilizing  property  the  foramen 
should  be  allowed  to  remain  unsealed  until  after  the  bleaching  operation 
has  been  completed.  It  sometimes  happens  that  the  improvement  in 
color  following  the  application  of  the  dioxid  methods  is  only  partial, 
and  the  result  falls  short  of  restoration  to  normal;  or,  in  other  words, 
the  bleaching  reaches  a  certain  point  beyond  which  the  color  resists  the 
further  action  of  the  bleaching  agent.  In  such  cases  the  decomposition 
of  the  color  molecule  has  probably-  resulted  in  the  formation  of  iron 
oxid  as  an  end  product.  In  practice  this  residual  discoloration  can 
generally  be  removed  by  treatment  with  oxalic  acid.  A  small  crystal 
is  to  be  sealed  in  the  moist  pulp  chamber  for  twenty-four  hours,  and 
afterward  washed  out  with  a  copious  irrigation  of  hot  distilled  water. 

The  sodium  dioxid  method  remo\es  more  completely  than  any 
other  the  tubular  contents,  and  the  result  is  uniciue  from  the  fact  that 
not  only  is  the  tooth  restored  to  normal  color,  but  to  normal  trans- 
lucency;  the  opaque  white  effect  resulting  from  other  methods  of 
bleaching  is  due  to  the  bleached  organic  debris  remaining  in  the  tubuli, 
but  by  the  solvent  action  of  the  strong  caustic  alkali  this  is  removed. 
The  final  treatment  of  the  tooth  is  the  same  in  this  as  in  other  methods, 
though  the  dentin  should  be  desiccated  and  saturated  as  thoroughly 
as  possible  with  an  unalterable  varnish  before  the  final  filling  is  inserted. 

The  Sulfur  Dioxid  Method. — Reference  has  already  been  made  to 
sulfur  dioxid  as  the  single  example  of  the  reducing  type  of  bleaching 
agent.  Its  activity  is  due  to  its  aflinity  for  oxygen,  and  it  bleaches 
by  seizing  upon  and  combining  with  that  element  of  the  color  molecule, 
thus  destroying  its  identity  and  consequently  its  color.  Attempts  have 
been  made  to  utilize  the  bleaching  property   of  sulfur  dioxid  in  the 


CATAPHORIC  BLEACHING  OF  TEETH  539 

treatment  of  discolored  teeth  by  direct  applications  of  the  solution  of  the 
gas  in  water  and  by  igniting  small  (juantities  of  sulfur  in  the  root  canal 
by  means  of  the  electrocautery  wire.  These  methods  have,  however, 
proved  inefficient.  The  gas  may  be  successfully  used  in  bleaching  teeth 
by  evolving  it  from  its  compounds  placed  in  the  cavity  and  root  canal 
in  a  manner  analogous  to  that  employed  in  the  Truman  chlorin  process, 
already  described.  For  this  purpose  the  writer's  method  may  be  con- 
veniently employed:  100  grains  of  sodium  sulfite  and  70  grains  of  boric 
acid  are  separately  desiccated  and  afterward  ground  together  in  a 
warm  dry  mortar.  The  powder  is  then  to  be  transferred  to  a  tightly 
stoppered  bottle.  For  bleaching  purposes  the  powder  is  packed  into  the 
root  canal  and  cavity  of  the  tooth,  and  then  moistened  with  a  drop  of 
water  and  the  cavity  immediately  closed  as  tightly  as  possible  with  a 
stopping  of  gutta-percha  previously  prepared  and  warmed.  A  reaction 
ensues  between  the  boric  acid  and  sodium  sulfite  whereby  sulfur  dioxid 
is  liberated,  thus: 

2H3BO3  +  SNaoSO,  =  2Na3B03  +  3H,0  +  SSOj. 

The  process  is  effective  in  many  cases  in  which  the  chlorin  methods 
have  failed,  but  is  slow  in  its  action,  and  is  largely  superseded  by  the 
hydrogen  dioxid  and  sodium  dioxid  methods. 


CATAPHORIC  BLEACHING  OF  TEETH 

It  has  been  found  that  aqueous  solutions  of  hydrogen  dioxid  may  be 
carried  into  the  dentinal  structure  with  great  ease  by  the  cataphoric 
action  of  the  continuous  current.  The  appliances  necessary  for  tooth- 
bleaching  operations  by  this  means  are  practically  the  same  as  those 
required  in  the  treatment  of  hypersensitive  dentin.  The  resistance 
offered  by  the  hard  structures  of  the  tooth  is  much  greater  after  loss 
of  the  tooth  pulp,  requiring  a  much  higher  voltage  pressure  to  drive  the 
bleaching  agent  into  the  tissue.  While  in  some  cases  25  to  30  volts  will 
be  all  that  is  necessary,  some  cases  will  require  as  high  as  60  volts  to 
carry  1.5  milliamperes  of  current  through  the  dentin.  The  ethereal 
solution  of  hydrogen  dioxid  has  been  found  to  oppose  too  great  resistance 
to  the  current,  but  the  aqueous  solution,  containing  a  slight  addition  of 
some  salt  to  increase  its  conductivity,  is  entirely  manageable. 

A  25  per  cent,  aqueous  solution  of  hydrogen  dioxid  may  be  quickly 
made  by  shaking  together  in  a  test-tube  one  volume  of  water  and  two 
volumes  of  25  per  cent,  pyrozone.  The  H2O2  dissolves  in  the  water, 
and  the  ether  of  the  pyrozone  may  be  removed  by  pouring  the  mixture 
into  a  small  evaporating  dish  of  porcelain  or  glass  and  gently  heating  it 
over  a  water  bath  until  all  of  the  ether  has  evaporated.    The  addition 


540  DISCOLORED  TEETH  AND  THEIR  TREATMENT 

of  a  small  quantity  of  sodium  acetate  or  sulfate  will  f^rcatly  diminish 
the  resistance  of  the  sohition  to  the  i)assage  of  the  current. 

With  the  tooth  isolated  by  the  rubber  dam  and  having  received  the 
treatment  preliminary  to  bleachiiif]^,  as  already  described  in  detail,  the 
aqueous  solution  of  ILOj  is  droi)ped  upon  cotton  within  the  tooth 
cavity  and  a  platinum  needle  anode  is  applied  in  contact  with  it.  The 
cathode  may  be  a  sponge  electrode  moistened  with  salt  solution  and 
held  in  the  hand  or  applied  to  the  cheek  or  neck.  The  hand,  however, 
is  preferable  because  of  the  amount  of  voltage  required  in  the  operation. 
Great  care  must  be  exercised  that  the  external  surfaces  of  the  tooth  are 
kept  dry,  so  that  short-circuiting  of  the  current  may  not  take  place.  In 
some  cases  a  more  rapid  effect  is  obtained  by  making  contact  of  the 
cathode  pole  through  a  needle  electrode  upon  the  external  surface  of  the 
tooth,  and  with  the  anode  applied  to  the  pyrozone  solution  on  cotton 
within  the  tooth.  The  cotton  must  at  all  times  be  kept  wet  with  the 
solution. 

The  arrangement  of  the  electrical  terminals  with  respect  to  the 
bleaching  operation  is  both  theoretically  and  practically  correct  as  de- 
scribed, viz.,  the  flow  of  current  should  be  from  the  anode  point  through 
the  bleaching  solution  and  tooth  and  the  body  of  the  patient  to  the 
cathode.  In  practice  it  has  been  found  in  some  cases  which  have  failed 
to  bleach  with  the  elements  arranged  in  the  series  as  stated,  that  upon 
re\'ersing  the  poles  and  direction  of  current  flow  the  bleaching  has 
rapidly  followed.  The  explanation  of  this  apparent  paradox  is  that 
by  the  application  in  normal  order  H2O2  was  first  carried  into  the 
tubular  structure,  and  the  reversal  of  the  current  has  acted  upon  the 
tubular  contents  now  saturated  with  the  dioxid,  and  by  its  propulsive 
as  well  as  electrolytic  effect  removed  the  pigmentary  matter  pulpward 
from  the  tubuli.  Bleaching  with  reversed  poles  would  be  impossible 
without  previous  saturation  of  the  dentin  by  the  dioxid  solution. 

Dr.  INI.  W.  Ilollingsworth  has  devised  an  ingenious  apparatus  for 
cataphoric  bleaching  which  is  of  special  value,  as  it  makes  possible 
the  enveloping  of  the  entire  tooth  with  the  bleaching  fluid,  in  which 
it  is  immersed  as  in  a  bath.  The  appliance  is  shown  in  situ  in 
Fig.  569,  and  consists  of  a  thin  vulcanized  caoutchouc  bull)  shaped 
like  the  bulb  of  a  medicine  dropper.  Through  a  perforation  at  its 
rounded  end,  made  with  the  ordinary  rubber  dam  punch,  the  tooth 
is  slipped  by  mounting  the  bulb  on  the  applicator  (Fig.  570),  and  forcing 
it  over  the  tooth  as  though  it  were  a  rubber  dam.  A  glass  tube  is  then 
attached  to  the  open  end  of  the  bulb,  and  to  the  glass  tube  is  connected 
a  spiral  platinum  wire  electrode  (Fig.  571).  Before  the  electrode  is 
attached  the  bulb  and  glass  tube  are  completely  filled  with  the  aqueous 
pyrozone  solution  by  means  of  a  duplex  syringe  (Fig.  572),  the  lower 
and  larger  bulb  of  which  exhausts  the  contained  air  in  the  apparatus 
and  the  smaller  thumb  bulb  injects  the   bleaching  solution  into  the 


CATArilOJilC  liLKACIIINa  OF  TEETH 
Fio   509 


541 


Hollingsworth's  device  for  applying  the  bleaciiing  agent  to  the  tooth. 
Fig.  570 


Tube  electrode. 
Fig.  572 


Duplex  syringe. 


542  DISCOLORED  TEETH  AND  Til  EI  It  TREATMENT 

exhausted  apparatus.  Connection  is  now  made  with  the  source  of  cur- 
rent as  usual,  and  the  bleaching  is  very  rapidly  effected.  T)r.  Hol- 
lingsworth  recommends  the  addition  of  about  1  per  cent,  of  zinc  sulfate 
to  the  aqueous  p\rozone  solution,  which  not  only  diminishes  the  resist- 
ance to  the  passage  of  the  current,  but  has  a  coagulating  effect  upon 
the  bleached  organic  matter,  which  gives  it  translucency  and  greatly 
enhances  the  permanency  of  the  operation.  The  results  obtained  by 
this  method  are  extremely  satisfactory. 

Actinism  as  an  Adjuvant  to  the  Bleaching  Process. — The  efficiency  of 
sunlight  as  a  bleacher  has  long  been  known  and  practically  utilized 
in  the  bleaching  of  cotton  and  linen  fabrics,  both  on  a  commercial  scale 
and  in  domestic  practice.  The  tendency  of  vegetable  and  some  mineral 
coloring  matters  to  fade  in  the  sunlight  is  a  phenomenon  of  common 
observation.  It  is  known  that  the  power  possessed  by  light  of  bringing 
about  chemical  changes  is  a  property  which  is  not  shared  equally  by  all 
parts  of  the  solar  spectrum,  but  is  most  marked  in  the  violet  and  ultra- 
violet rays  when  the  undulations  are  of  highest  frequency.  Advantage 
has  been  recently  taken  of  the  actinic  factor  of  light  as  an  adjuvant 
to  the  tooth-bleaching  'process  in  connection  with  hydrogen  dioxid  by 
Dr.  Pfliiger,  of  Hamburg.  The  method  consists  in  making  an  applica- 
tion of  perhydrol  on  cotton  to  the  pulp  chamber  of  the  discolored  tooth 
and  also  coating  the  crown  with  the  bleaching  agent,  then  concentrating 
with  a  double  convex  lens  a  beam  of  light  from  an  electric  arc  lamp 
upon  the  tooth,  which  in  the  course  of  from  fifteen  to  thirty  minutes  is 
restored  to  its  normal  color  in  cases  amenable  to  the  bleaching  action 
of  the  dioxids.  Experiments  by  Dr.  Pfliiger  have  shown  that  when  the 
actinic  effect  of  the  light  is  used  the  action  of  the  hydrogen  dioxid  is  much 
more  rapid  and  efficient  than  when  used  without  the  light.  Tests  of 
actinic  rays  with  bleaching  agents  other  than  hydrogen  dioxid  have 
not  as  yet  been  made,  but  the  use  of  the  rays  in  such  connection  would 
seem  to  be  promising  of  usefulness. 


BLEACfflNG  METHODS  FOR  SPECIAL  STAINS 

Pulpless  teeth  are  specially  liable  to  discoloration  from  external  and 
accidental  causes.  If  decayed  and  the  cavity  has  remained  unfilled  for 
a  length  of  time,  many  substances  which  find  their  way  into  the  oral 
cavity  either  as  food  or  as  medicine  may  produce  discoloration  when 
absorbed  by  the  tooth  through  the  open  cavity  walls. 

Metallic  salts  are  particularly  apt  to  cause  such  staining  by  reaction 
with  the  sulfids  with  which  the  dentin  structure  is  usually  saturated 
during  decomposition  of  its  organic  contents.  Alany  of  the  medica- 
ments used  in  pulp-canal  treatment,  or  even  for  hypersensitive  dentin, 
may  stain  the  tooth  structure,  and  finally  the  action  of  sulfids  in  the 


BLEACHING  METHODS  FOR  SPECIAL  STAINS  543 

striictiiro  of  a  piilpless  tooth  may  react  with  amalgam  fillings,  forming 
salts  of  mercury,  silver,  tin,  copper,  etc.,  which  are  absorbed  by  the 
tooth,  resulting  in  its  discoloration.  The  treatment  of  these  stains, 
which  were  grouped  as  Class  III  at  the  beginning  of  this  chapter, 
is  extremely  difficult  and  often  unsatisfactory.  However,  there  may 
arise  indi^•idual  cases  of  discolorations  of  this  class  in  which  it  is  of  the 
utmost  importance  to  remove  them,  and  much  may  often  be  accom- 
plished when  the  causes  of  the  discoloration  are  known  and  the  proper 
bleaching  method  is  applied. 

Gold  stains  may  arise,  as  has  been  already  indicated,  from  the  inju- 
dicious use  of  gold  instruments  or  failure  to  remove  all  gold  fillings 
when  applying  some  one  of  the  chlorin  methods  of  bleaching.  In  the 
course  of  time  when  this  has  happened  the  tooth  assumes  a  pinkish 
hue,  which  merges  into  a  characteristic  violet  or  purple,  finally  becoming 
black. 

Iron  stains  ma^'  arise  from  the  use  of  steel  instruments  in  connection 
with  the  chlorin  methods  of  bleaching  or  in  contact  with  iodin  or  any 
of  the  mineral  acids  in  connection  with  canal  treatment.  The  iron  stain 
is  yellowish  at  first,  gradually  becoming  brown  and  finally  black. 

Copper  and  nickel  stains  may  arise  from  contact  wath  these  metals 
or  their  alloys,  as  copper  amalgam  or  nickel  or  German  silver  dowels 
for  artificial  crowns  or  anchorages  for  fillings.  The  stains  from  these 
metals  are — for  copper,  bluish  to  black,  and  for  nickel,  a  characteristic 
chlorophyl  green,  which  eventually  becomes  black. 

The  best  general  treatment  for  all  of  the  foregoing  stains  is  to 
bleach  the  tooth  by  the  chlorin  method,  with  special  care  as  to  the 
several  precautions  already  recommended;  and  when  the  color  of  the 
metallic  stain  has  been  discharged  by  conversion  of  the  dark-colored 
salt  into  a  soluble  chlorid,  wash  the  tooth  thoroughly  first  with  dilute 
chlorin  water,  50  per  cent.,  and  afterward  with  hot  distilled  water,  to 
remove  all  of  the  metallic  chlorid  which  has  been  formed.  The  process 
may  require  repetition  to  secure  permanent  results. 

Silver  stains  are  comparatively  easy  to  remove,  either  by  an  appli- 
cation of  the  chlorin  method  or  by  saturating  the  tooth  with  tincture  of 
iodin,  thus  converting  the  silver  salt  into  a  chlorid  or  iodid,  as  the  case 
may  be,  after  w^iich  it  may  be  dissolved  out  with  a  saturated  solution 
of  sodium  hyposulfite  applied  as  a  bath  to  the  tooth.  For  this  pur- 
pose the  Hollingsworth  bulb  dam  (see  Fig.  569)  answers  admirably, 
and  although  the  experiment  has  not  as  yet  been  tried,  there  is  good 
reason  to  believe  that  the  cataphoric  method  with  electrodes  applied  in 
reverse  order  would  under  these  circumstances  greatly  facilitate  the 
solution  and  removal  of  the  metallic  salts. 

Mercurial  stains  are  always  black  from  the  formation  of  mercuric 
sulfid,  and  are  removable  by  the  same  method  as  are  silver  stains,  with 
the  exception  that  when  the  stain  has  been  converted  into  a  chlorid 


544  DISCOLORED  TEETH  AND  THEIIi   TREATMENT 

by  the  chlorin  method,  the  mercuric  chloric!  is  best  removed  by  an 
aqueous  ammoiiiacal  solution  of  hydrogen  dioxid,  or  when  the  stain 
has  been  converted  into  mercuric  iodid  by  the  use  of  a  saturated  solu- 
tion of  potassium  iodid.  In  both  cases  a  final  washing  with  hot  dis- 
tilled water  is  a  sine  qua  non. 

Manganese  stains  frequently  occur  from  the  use  of  potassium  per- 
manganate, in  solution  or  in  substance,  in  the  treatment  of  putrescent 
canal  conditions.  The  manganese  stain  is  a  characteristic  mahogany 
brown.  It  is  very  readily  removed  by  a  25  per  cent,  aqueous  solution 
of  hydrogen  dioxid  in  which  oxalic  acid  crystals  have  been  dissolved  to 
saturation.  A  few  applications  of  this  mixture  will  quickly  decolorize 
the  stain,  after  which  a  liberal  treatment  of  hot  distilled  water  is 
required  as  in  the  foregoing  cases. 

In  all  cases  a  careful  diagnosis  of  the  chemical  nature  of  the  dis- 
coloration should  be  made  when  possible.  Much  information  upon  this 
point  may  be  gained  by  a  detailed  study  of  the  present  condition  of  the 
tooth  and  its  environment,  but  in  addition  to  this  the  patient  should  be 
questioned  as  to  the  history  of  the  case,  and  especially  as  to  its  previous 
treatment.  The  data  thus  obtained  should  be  carefully  noted,  and  treat- 
ment instituted  in  accordance  with  the  conditions  to  be  met. 

Success  in  the  bleaching 'of  teeth  demands  a  recognition  of  the  fact 
that  each  case  presents  individual  peculiarities,  that  the  problem  is 
essentially  a  chemical  one  always,  and  that  the  bleaching  method  in  any 
given  case  must  be  selected  with  special  reference  to  the  character  of 
the  discoloration  and  applied  with  due  care  as  to  its  details  in  order  that 
the  chemical  requirements  of  the  operation  may  be  intelligently  met; 
without  which  care  success  is  impossible. 


CHAPTER    XVII 
EXTRACTION  OF  TEETH 

By  M.  H.  CRYER,  M.D.,  D.D.S. 
INDICATIONS  FOR  THE  OPERATION 

It  is  impossible  to  formulate  a  set  of  exact  rules  bv  which  the  prac- 
titioner may  be  governed  in  deciding  upon  the  extraction  of  teeth.  So 
many  circumstances,  both  local  and  general,  must  be  taken  into  consid- 
eration that  little  more  can  be  done  than  to  suggest  the  most  important 
causes  which  demand  the  operation. 

Deciduous  Teeth. — The  indications  for  extracting  deciduous  teeth 
are — 

First:  When  the  teeth  are  a  source  of  irritation  affecting  the  general 
health  or  comfort  of  the  child  and  do  not  respond  to  treatment. 

Second:  When  the  deciduous  teeth  are  preventing  the  eruption  of 
the  permanent  teeth  into  their  normal  positions.  Occasionally  a  de- 
ciduous tooth  will  assist  in  the  proper  placing  of  a  permanent  one, 
in  which  case  it  should  not  be  removed  as  long  as  it  is  of  such  use. 

Third:  When  a  lower  permanent  incisor  shows  signs  of  erupting  on 
the  labial  side  of  the  deciduous  tooth  the  latter  should  be  removed  at 
once,  but  if  the  erupting  tooth  appears  on  the  lingual  side  the  removal 
of  the  deciduous  tooth  may  in  that  case  be  delayed  somewhat  longer. 

Fourth:  ^^^len  upper  permanent  incisors  show  a  tendency  to  erupt 
on  the  palatal  side  of  the  temporary  teeth  the  latter  should  be  extracted, 
but  when  they  are  erupting  on  the  labial  side  the  deciduous  teeth  may 
be  allowed  to  remain  for  a  time,  as  they  are  often  useful  in  forcing  the 
permanent  teeth  outwardly.  This,  however,  must  be  closely  watched 
to  prevent  the  permanent  incisors  from  moving  too  far. 

Permanent  Teeth. — The  indications  for  extraction  of  the  permanent 
teeth  are — 

First:  Diseased  roots  which  cannot  be  cured  and  so  made  useful 
for  crowning,  or  assisting  in  retaining  a  bridge,  plate,  or  other  pros- 
thetic device. 

Second:  Teeth  of  mastication  that  have  lost  their  occluding  teeth 
and  in  consequence  thereof  are  being  pushed  from  their  alveoli  and  are 
a  source  of  trouble.  As  a  rule,  this  refers  only  to  the  second  or  third 
molars,  and  more  particularly  to  the  third  molar.  When  it  occurs  with 
other  teeth  the  opposite  vacant  space  should  be  filled  by  an  artificial 
tooth  to  prevent  the  extrusion  of  the  natural  tooth. 

35  (545) 


546  KXTRAVTION  OF   TEETH 

Third:  When  incurable  abscesses  originating  from  teeth  in  the  upper 
jaw  tend  to  open  into  the  nasal  chamber,  maxillary  sinus,  or  zygomatic 
fossa  the  teeth  associated  with  such  abscesses  should  be  extracted. 
When  diseased  teeth  are  the  exciting  cause  of  an  incurable  abscess  in 
the  lower  jaw  which  opens  or  threatens  to  open  externally  on  the  chin, 
jaw,  or  below  the  bone  into  or  upon  the  neck,  they  should  be  removed. 

Fourth:  Teeth  which  occupy  irregular  })ositions  in  the  arch,  that 
cannot  be  corrected  so  as  to  become  useful  or  contribute  to  the  general 
symmetry  of  the  mouth,  should  be  removed. 

Fifth:  Erupting  teeth  that  are  retarded  because  of  lack  of  room 
in  the  jaw,  if  giving  pain,  or  are  causing  reflex  disturbances,  should  be 
extracted  or  else  the  tooth  that  is  preventing  the  eruption  should  be 
removed.  A  marked  example  of  this  is  often  found  in  the  eruption  of 
the  third  molar  when  all  the  other  teeth  are  of  good  size  and  are  in 
place.  These  molars  when  retarded  often  cause  the  greatest  distress, 
sometimes  producing  serious  results,  and  must  then  be  extracted;  if  they 
cannot  be  safely  removed  the  second  molar  may  be  extracted,  in  conse- 
quence of  which  the  third  molar  will  usually  be  erupted  near  its  place. 
When  an  upper  third  molar  is  erupting  under  the  same  circumstances 
there  is  usually  less  dffficulty,  as,  having  but  slight  resistance  distally, 
it  can  erupt  outwardly  or  slightly  backward,  though  should  it  impinge 
upon  the  soft  tissues  covering  the  ramus  of  the  lower  jaw  it  should  be 
extracted. 

Sixth:  Teeth  so  badly  diseased  that  they  will  not  respond  to  treat- 
ment and  are  a  source  of  discomfort  to  the  patient  should  be  removed, 
as  they  impair  the  general  health. 

Seventh:  First  molars.  There  has  been  much  discussion  regarding 
the  early  extraction  of  these  teeth,  many  claiming  that  if  the  pulp  of 
one  becomes  devitalized  at  an  early  period  of  life  and  it  is  deemed  best 
to  extract  it,  the  other  three  should  also  be  removed.  No  fixed  general 
rule,  however,  can  be  given;  each  case  must  be  considered  separately. 
There  are  cases  where  the  extraction  of  all  is  necessary,  and  others 
where  it  would  be  a  most  unwise  thing  to  do.  When  the  anterior  teeth 
are  fully  in  position,  the  bicuspids  occluding  correctly  and  the  second 
molars  are  about  to  erupt,  the  case  may  then  be  one  for  extracting  the 
four  first  molars,  provided  it  be  necessary  to  extract  one  of  them,  or 
if  it  be  likely  that  one  or  more  of  them  will  be  lost  in  a  few  years.  If, 
however,  the  bicuspids  are  not  in  good  position,  it  is  better  not  to  extract 
the  first  molars,  as  they  assist  in  keeping  the  jaws  the  proper  distance 
apart,  and  in  preventing  the  lower  anterior  teeth  from  biting  against 
the  upper  gum. 

Removal  of  Sound  Teeth  Preparatory  to  Inserting  Artificial  Dentures.— 
When  preparing  the  mouth  for  an  artificial  denture  the  removal  of  sound 
teeth  may  be  indicated  as  a  measure  of  expediency  in  relation  to  mechan- 
ical and  hygienic  considerations.    For  example : 


INDICATIONS  FOli  THE  OPERATION  547 

1.  Roots  wliich  a  plate  or  bridge  would  eover,  excepting  when  they 
assist  in  holding  the  device. 

2.  Teeth  from  which  (he  gums  have  receded  to  such  an  extent  as 
to  become  useless  or  unsightly. 

3.  Teeth  that  are  being  extruded  from  their  alveoli  from  the  ab- 
sence of  occluding  teeth.  The  extraction  of  these  depends,  however, 
on  the  extent  of  "elevation"  and  the  possibility  of  placing  occluding 
artificial  teeth  in  position. 

4.  Where  there  is  but  one  tooth  remaining,  or  two  teeth  standing 
together,  or  in  certain  cases  when  several  isolated  teeth  remain  which 
cannot  be  made  to  contribute  to  the  mechanical  adaptation  of  an  arti- 
ficial denture,  extract  when  in  the  upper  jaw.  They  interfere  with  the 
fitting  of  an  upper  plate,  but  in  the  lower  jaw  they  may  be  useful  in 
retaining  the  plate. 

5.  When  there  are  two  teeth',  one  on  each  side  of  the  upper  jaw,  in 
good  position  and  of  desirable  shape  for  clasping,  do  not  extract  unless 
they  are  the  third  molars  or  the  oral  teeth. 

6.  In  preparing  the  upper  jaw  when  two  canine  teeth  alone  remain, 
or  when  there  is  also  a  molar  or  bicuspid,  or  both,  and  it  is  decided  to 
extract  the  molars  and  bicuspids,  then  extract  the  two  canine  teeth  also. 
It  has  been  claimed  by  some  of  the  very  best  dental  practitioners,  whose 
opinions  must  be  respected,  that  by  keeping  these  teeth  the  expression 
of  the  face  is  less  likely  to  be  marred.  For  the  following  combined 
reasons,  however,  extraction  is  advised: 

(ff)  It  is  very  difficult  to  obtain  a  correct  impression  of  the  mouth 
while  these  teeth  only  are  in  position. 

(b)  It  is  nearly  impossible  to  perfectly  match,  grind,  and  arrange  the 
lateral  incisors  beside  single  canines. 

(c)  The  adhesion  of  the  plate  to  the  mouth  is  interfered  with,  as  air 
and  food  work  in  between  the  plate  and  these  natural  teeth, 

(d)  The  plate  is  very  much  weakened  by  being  cut  out  for  the  accom- 
modation of  these  teeth  at  what  might  be  termed  the  abutments  of  the 
arch. 

In  the  lower  jaw  single  teeth  which  are  sound  are  usually  of  great 
importance.  They  should  not  be  removed,  as  they  assist  in  retaining 
a  denture  by  means  of  clasps  or  other  devices.  Especially  is  this  true 
in  persons  advanced  in  years,  as  then  the  alveolar  process  is  generally 
much  absorbed.  If  the  lower  process  is  much  absorbed,  even  an  imper- 
fect tooth  will  do  good  service  of  this  character  for  a  time;  and  if  it  is  the 
first  plate  the  patient  has  worn  it  will  serve  a  good  purpose  by  assisting 
in  the  retention  of  the  plate  until  the  patient  has  become  accustomed 
to  it,  after  which  the  tooth,  if  giving  trouble,  or  if  it  is  unsightly,  may 
be  removed  and  an  artificial  one  placed  on  the  plate. 


548 


EXTRACTION  OF  TEETH 


Fio.   573 


INSTRUMENTS  AND  ACCESSO- 
RIES FOR  EXTRACTING 

The  instruments  used  in  ex- 
tractinjj;  teeth  are  foreeps  and 
elevators  of  various  shapes  and 
sizes. 

Forceps. — The  forceps  should 
be  made  of  steel  of  the  best  c|ual- 
ity  for  the  purpose  obtainable,  in 
order  to  give  great  strength  and 
stiffness  and  at  the  same  time 
toughness,  so  that  they  will  not 
break.  Forceps  that  will  spring 
or  bend  destroy  the  sensitivity  of 
the  hand  using  them  in  such  a 
way  as  to  prevent  the  operator 
from  discerning  in  what  direc- 
tion the  resistance  to  extraction 
is  being  made.  The  beaks  of  the 
forceps    as    a    general    principle 

Fig.  574 


Antiseptic  universal  lower  molar  forceps. 


Joint  of  ail  antiseptic  lower  molar  forceps. 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING      549 


Fig.  575 


.sliould  he  shaped  .so  as  to  fit  and  adjust  themselves  to  as  great  a 
of  tlu'  various  teeth  or  roots  as  possible,  so  that  they  may  take 
hoUl.  Tiiev  should  be  at  such  an 
an^le  in  relation  to  the  handles 
as  will  permit  them  to  be  easily 
antl  readily  placed  in  the  proper 
position  without  obscuring  the 
view  of  the  tooth  to  be  extracted. 
The  inner  surface  of  each  beak 
should  be  concave  in  a  transverse 
section  and  without  serrations,  as 
these  are  of  no  assistance,  but 
tend  to  weaken  the  beaks  and  are 
difficult  to  clean.  The  edges  of 
the  concave  portion  should  be 
sharp  enough  to  cut  through  the 
alveolar  process  if  necessary. 
The  points  of  the  beaks  should 
be  sharp  and  tapering  so  they  can 
be  forced  into  position.  The 
handles  should  be  of  a  shape  to 
allow  a  firm  grasp,  and  as  the 
hands  of  different  operators  vary 
in  shape  and  size  it  will  be  evi- 
dent that  the  same  size  of  forceps 
handles  will  not  be  perfectly  sat- 
isfactory to  all.  The  curvature 
of  the  handles  should  vary  ac- 
cording to  the  general  or  special 
use  of  the  forceps.  The  curved 
ends,  as  seen  in  Fig.  573,  are  of 
little  use,  and  should  be  done 
away  with  in  all  forceps  excepting 
perhaps  those  made  especially  for 
the  upper  and  lower  molars. 

The  joints  of  extracting  instru- 
ments should  be  so  made  that 
the  handles  can  be  separated  by 
some  simple  mechanism  to  permit 
of  thoroug-h  and  easv  cleansino-. 
Figs.  573  and  574  represent  an 
instrument  of  this  charactei-. 
There  are  others  of  the  same 
nature,  but  this  being   the  most 

simple   and    the    strongest   should  Knuckle-joint  root  forceps. 


surface 
a  firm 


550  EXTRACTION  OF  TEETH 

be  generally  adopted  unless  a  similar  device  can  be  adapted  to  the 
"knuckle-jointed"  instrument  (Fig.  575). 

There  should  be  no  sharp  angles  or  crevices,  and  if  the  ordinary 
forceps  be  used,  that  portion  around  the  joint  in  a  transverse  section 
should  be  oval.  Forceps  are  often  made  with  octagonal  joints,  but  these 
should  be  condemned,  as  they  may  not  only  hurt  the  lips  of  the  patient, 
but  in  case  of  a  slip,  which  may  happen  with  the  l)est  operators,  they 
are  more  liable  to  cause  injury  by  striking  the  other  teeth;  moreover, 
they  are  very  clumsy  and  require  more  room. 

Unless  the  antiseptic  joint  (Figs.  573  and  574)  is  used  the  union  of 
the  joints  is  usually  made  upon  one  of  two  principles:  First,  by  one-half 
passing  into  a  mortise  in  the  other  and  held  in  the  centre  by  a  pinion 
(Fig.  576).  The  second  is  known  as  a  knuckle-joint  (Fig.  575)  made 
by  each  portion  being  let  half-way  into  the  other  and  held  together 
by  a  screw.  This  is  a  neater  joint  and  does  away  with  many  of  the 
objectional  features  noted  in  other  forms  of  forceps  joint. 

All  handles  should  be  serrated,  as  shown  in  the  illustrations,  and  the 
instruments  if  properly  cared  for  need  not  be  nickel-plated.  The 
number  of  forceps  in  a  practical  set  will  vary  with  the  requirements  of 
every  individual  who  extracts  teeth,  therefore  only  the  general  principles 
which  should  govern  the  selection  of  a  set  of  instruments  will  be  here 
given;  at  the  same  time  the  uselessness  of  a  very  large  selection  is  here 
emphasized.  As  an  illustration  of  the  range  of  tooth  extractions  which 
may  be  performed  with  a  limited  number  of  instruments,  the  forceps 
represented  by  Figs.  576  and  577,  showing  the  exact  size,  will  serve  as 
examples.  They  are  smaller  than  the  ones  generally  used,  especially  in 
America. 

The  instruments  shown  in  Fig.  576  may  be  used  almost  universally  for 
the  upper  teeth. 

Fig.  577  is  a  forceps  of  the  same  general  character  as  that  in  Fig. 
576,  only  the  beaks  are  at  a  different  angle  with  the  handles.  This  pair 
may  be  used  similarly  for  the  lower  teeth.  These  forceps  are  useful  in 
all  cases,  except  in  the  full  arch,  when  either  a  first  or  second  molar  is 
to  be  extracted.  If  the  teeth  are  large,  the  jaw  strong,  and  the  line  of 
grinding  surfaces  concave,  it  is  better  to  use  the  special  lower  molar 
forceps  as  shown  in  Figs.  573  and  586. 

Figs.  578  and  579  represent  very  useful  forceps  for  extracting  the 
ten  upper  anterior  teeth.  Fig.  579  has  longer  beaks  and  its  points  are 
finer.  In  skilful  hands  where  too  great  a  force  will  not  be  brought  to 
bear  on  the  points  they  are  the  better  forceps.  Under  nitrous  oxid 
and  where  many  teeth  are  to  be  extracted,  thus  recjuiring  rapid  work,  the 
instrument  shown  in  Fig.  578  is  preferable. 

Figs.  580  and  581,  right  and  left,  represent  forceps  specially  used  for 
extracting  the  first  and  second  upper  molars  on  either  side.  The  outer 
beak  is  made  pointed  for  the  pui'pose  of  passing  in  between  the  buccal 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING      551 

roots,  the  inner  beak  is  concave  in  order  to  grasp  the  palatal  root.    Figs. 
583  and  584  show  bayonet-shaped  forceps,  that  illustrated  by  V\g.  583 


Fig.  576 


Fig.  577 


gs§ 


M 

MM 


^^y 


Universal  upper  incisor  and  root  forceps. 


Universal  lower  incisor  and  root  forceps. 


being  specially  made  for  extracting  the  upper  third  molars,  Fig.  584 
being  used  for  upper  roots.    The  ends  of  the  handles  of  all  forceps  which 


552 


EXTRACTION  OF  TEETH 


Fin.   578 


Fic!.  570 


M 

m 


f 

m 


mil 


For  the  ten  upper  anterior  teeth. 


Koot,  iijiper  front  (straight). 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING      553 


Fin 


are  forced  in  bv  the  ])alm  of  the  hand  should  have  a  broad  surface,  as 
shown  in  Fig.  5cS4.  These  forceps  are  po})uhir  with  many  operators. 
The  writer  considers  them 
chnnsy,  as  they  obscure  the 
])roper  view  of  the  tooth  and 
its  associated  parts. 

Forceps  for  E.xirnciincj  Lovrr 
Tccih. — Instead  of   the    beaks 
of  the  forceps  being  nearly  on 
a  line  with  the  handles,  as  in 
those  for  the  upper  jaw,  they 
are  bent  at  nearly  a  right  angle. 
For  the  incisors  of  the  lower 
jaw  there  are  no  better  forceps 
than  those  shown  in  Fig.  577. 
This  instrument  is  very  useful 
in   extracting   the   lower  third 
molar  when  fixation  of  the  jaw 
from   diifuse    cellulitis    in   the 
region  of  the  temporomaxillary 
articulation  renders  it  difficult 
to  open  the  mouth  sufficiently 
for    inserting   a  larger   instru- 
ment.    In  such  cases  the  for- 
ceps should  be  carried   back- 
ward in    the   vestibule  of    the 
mouth    with    the    inner  beak 
passing  between  the  upper  and 
lower   teeth;   when   the  beaks 
reach  the  third  molar  the  in- 
ner beak  can  usually  be  forced 
over  the  inner  surface  of    the 
tooth  and  into  position,  after 
which  the  tooth  can  be  grasped 
and    extracted.     The    forceps 
represented    in   Fig.    576    can 
also  be  used  to  advantage  for 
these  teeth,  the  operator  stand- 
ing  behind  and  working;  over 
the    head    of    the    patient,  as 
shown  in  Fig.  639. 

Fig.  582  exhibits  a  hawk- 
beaked  forceps  for  extracting 
the  anterior  lower  teeth.  It  is 
very  popular  with  some  oper-  Hight  upper  molar. 


554 


EXTRACTIOX  OF  TEETH 


ators,  especially  those  in  Europe.    The  writer  does  not  recommend  it. 
Fio-.  585  also  exhibits  a  special  instrument.     It  is  made  for  extracting 


Fig.  581 


Fig.  582 


Left  upper  molar. 


Hawk-beaked  forceps. 


JXSTRl'MEXTS  AND  ACCESSORIES  FOR  EXTRACTING      555 


Fir..  583 


Fig.  584 


m 


Universal  upper  third  molar. 


Dorr's  upper  root  forceps. 


556 


EXTRACTION  OF  TEETH 


the   lower    canine   and    bicuspid    teeth  of   either   side.      Fig.  586  is  a 
special  instrument  used  for  the  lower  molars  of  either  side.     The  beaks 


Fro.  r.S.') 


Fir..  r,8r> 


Universal  lower  canines  and  bicuspids. 


Universal  lower  molars,  designed  by 
Dr.  Chapin  A.  Harris. 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING      557 


Fio.  587 


Fig.  588 


Fio.  589 


Root,  lower.    Half  curved. 


Elevator, 


Right  and  left  scalers  used 
for  extracting  roots. 


558 


EXTRACTION  OF  TEETH 


are  pointed,  with  a  concavity  on  each  side  of  the  point  to  allow  it  to  pass 
in  between  the  roots.    The  two  concave  portions  fit  against  each  root. 


Fig.  590 


Fk;.   591 


Lancets  with  ebony  handles  and  with  solid  steel  handles. 


Fig.  587  represents  a  universal  lower  root  forceps  which 
IS  preferred  by  many  to  that  show^n  by  Fig.  585. 

Elevators  or  Root  Extractors. — There  are  many  kinds  of 
'levators  used  in  extracting  roots.  Some  are  also  occasion- 
■  dly  used  in  the  extraction  of  teeth  (usually  the  third 
molar). 

Fig,  588  shows  one  of  the  most  useful  forms  of  this  instru- 
ment. It  is  especially  useful  in  extracting  third  molars  when 
die  teeth  in  front  of  them  are  in  position.  Also  for  the 
removal  of  impacted  teeth  by  passing  in  between  the  impacted 
loothandan  adjoining  tooth,  or  between  the  tooth  and  the 
I  lone,  the  concave  portion  being  placed  against  the  tooth  to  be 
lemoved.     It  is  also  useful  as  a  gouge  at  times  in  removing 

Ibone  that  is  overlying  an  impacted  tooth. 
Fig.  589  represents  two  elevators;  they  are  similar  to  right 
and  left  scalers,  being   made   somewhat  heavier;  they   are 
extremely  useful   in  extracting  roots.     They  are  so   unlike 
an  extracting  instrument  that  patients  do  not  dread  the  ap- 
pearance of  them  as  they  do  that  of  forceps.     By  carefully 
inserting  the  blade  with  the  point  toward  the    root    to  be 
removed,  between  it  and  the  adjoining  root  or  tooth,  and 
giving  a  slight  rotary  motion,  the  point  will   force  the  root 
from  its  socket  with  but  little  pain. 
Figs.  630  and  631  illustrate  two  other  forms  of  elevator,  with  their 
mode  of  application  in  the  removal  of  roots. 


Ii*"rfi?i 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING     559 


Fig.  592 


Lancets. — Figs.  590  and  591  represent  various  forms  of  lancets, 
the  more  useful  of  which  are  Nos.  1  and  5,  which  are  all  that  are  required 
for  lancing  in  extracting  or  for  relief  of  retarded  eruption  of  deciduous 
or  other  teeth.  They  are  also  useful  in  general  surgery  of  the  mouth. 
The  handles  should  be  made  of  metal  instead  of  wood,  in  order  that 
they  may  be  thoroughly  sterilized. 

Scissors. — A  good  pair  of  curved 
scissors,  as  shown  in  Fig.  592,  should 
be  at  hand  in  case  a  portion  of  gum 
tissue  is  found  to  be  attached  to  the 
root.  If  the  scissors  were  slightly  more 
curved  they  would  be  even  better 
adapted  for  this  purpose. 

In  connection  with  the  instruments 
already  mentioned,  there  should  be 
a  mouth  mirror  (Fig.  593)  and  a  few 
45  degree  angle  hatchet-shaped  exca- 
vators and  probes  for  general  exami- 
nation of  the  teeth,  especially  for 
examining  the  position  and  character 
of  a  root  or  impacted  tooth  which  it 
is  purposed  to  extract. 

Fig.  593 


Curved  scissors. 


Mouth  mirror. 


Mouth  Props. — When  an  anesthetic  is  to  be  given  it  is  advisable  to 
use  some  kind  of  a  mouth  prop,  in  order  to  keep  the  mouth  well  open. 
Corks  1^  inches  in  length,  1^  inches  at  the  base,  and  f  of  an  inch  at  the 
small  end  are  very  useful  for  this  purpose  when  placed  between  the 
jaws,  with  the  small  end  in  the  mouth.  Some  operators  do  not  use 
them,  as  they  may  interfere  with  the  giving  of  the  anesthetic  by  impeding 
respiration  upgn  beginning  the  administration.    The  majority  of  patients, 


500 


EXTRACTION  OF   TEKTII 


if  asked  to  hold  the  mouth  open  while  taking  the  anesthetic,  especially 
nitrous  oxid  and  oxygen,  will  keep  it  open  during  the  anesthetic  stage. 

P^ig.  594  illustrates  excellent  props  devised  by  Dr.  Frederic  Hewitt, 
of  London,  England. 


Fio.  594 


J^ 


Hewitt's  mouth  props  (half  size). 
Fin.   595 


Mechaniral  inoutii-opener  (half  size). 
Fk;.   50r) 


J'haryiiKoai  forceps  (half  size). 

The  Mechanical  Mouth-opener  (Fig,  595). — This  instrument  is  made 
in  various  shapes  and  sizes.  It  is  inserted  between  the  jaws  when  the 
props  are  to  be  removed  or  in  cases  of  trismus,  and  may  also  be  used 
to  separate  the  jaws  and  retain  them  so  in  cases  of  emergency  or  during 
certain  operations  within  the  oral  cavity. 

All  dentists,  and  especially  those  who  extract  teeth,  should  have  at 
least  one  pair  of  pharyngeal  forceps  (Fig.  596).  It  is  possible  that  they 
may  never  be  used,  but  on  the  other  hand  an  accident  may  occur  such  as 


SURGICAL  ANATOMY 


561 


a  fragment  or  tooth  slipping  into  the  pharynx,  where  if  the  finger  cannot 
reach  it  this  instrument  will  be  absolutely  necessary. 

Surgical  Anatomy. — ^To  extract  teeth  successfully  it  is  first  necessary  to 
be  perfectly  faniilar  with  the  general  shapes  of  the  different  teeth  and 
their  position  in  relation  to  the  jaw  and  to  their  associates,  in  order 
that  the  operator  may  intelligently  apply  the  force  in  the  line  of  the 
least  resistance  recjuired  for  their  removal.  This  knowledge  cannot 
be  obtained  from  books;  they  are  but  the  guides  to  it.  The  jaw^s  of  the 
dead  subject  must  be  dissected — both  the  cleaned  bones  and  those  with 
the  soft  tissues  left  upon  them.  "Dissection"  means  that  not  only 
shall  the  superficial  relations  be  studied,  but  that  the  bones  shall  be  cut 
in  various  directions,  both  with  the  saw  and  other  instruments,  until 
the  relations  of  the  teeth  of  the  upper  jaw  with  the  floor  of  the  nasal 
chamber  and  the  maxillary  sinus  are  fully  understood.  In  the  lower 
jaw  the  relations  of  the  teeth  with  the  inferior  dental  canal  and  the 
position  of  the  roots,  especially  those  of  the  third  molar,  must  also  be 
thoroughly  known. 

Fig.  597 


Alveoli  of  permanent  teeth  (upper  jaw). 


The  alveolar  process  of  both  jaws  is  made  up  of  two  plates,  external 
and  internal,  consisting  of  dense  compact  bone  without  a  true  line  of 
demarcation  between  the  process  and  maxilla  proper.  The  sockets  for 
the  roots  of  the  teeth  are  situated  in  the  interspaces  between  these  plates 
and  are  surrounded  by  a  very  thin  porous  plate  of  cortical  bone.  The 
remaining  space  is  filled  with  cancellated  tissue,  small  bony  channels, 
36 


562 


EXTRACTION  OF  TEETH 


connective  tissue,  nerves,  vessels,  etc.  As  this  process  )K'lonp;s  to  the  teeth, 
is  developed  with  them,  and  is  for  the  purpose  of  holdin*^  them  in  posi- 
tion, it  disappears  to  a  greater  or  less  extent  when  the  teeth  are  lost.  The 
resorption  of  this  process  does  not  take  place  alike  in  each  jaw.  In  the 
upper  jaw  the  external  plate  disappears  more  rapidly  and  to  a  greater 
degree  than  the  inner  plate;  in  the  lower  jaw  the  resorption  of  the  two 
plates  is  al)out  ecpial  in  extent  and  rate.  The  inner  plate  of  the  upper  jaw 
is  partially  supported  hy  the  external  plate  of  the  palatal  process;  in  fact, 
one  merges  into  the  other.  The  outer  alveolar  plate  of  the  upper  jaw 
being  resorbed  to  a  greater  extent  than  the  inner  one  is  of  advantage 


Fii;.  598 


Alveoli  of  perni.'inent  teeth  (lower  jaw). 


to  the  dentist  in  fitting  teeth  to  the  gums;  consequently,  in  extraction 
that  fact  should  be  remembered  and  injury  to  the  internal  plate  avoided. 
At  the  same  time  it  does  no  harm  to  remove  a  small  portion  of  the  outer 
plate,  though  loss  of  the  gum  tissue  should  be  avoided  if  possible.  In 
the  lower  jaw  it  is  not  so  important  to  avoid  removing  slight  portions 
of  the  inner  plate,  as  resorption  takes  place  about  ecjually  in  the  two 
plates. 

These  plates  may  be  resorbed  in  such  a  manner  that  a  slight  ridge 
is  left  between   the  places  which   they  occupied.     This  resorption  of 


SURGICAL  ANATOMY 


5(53 


both  plates  t)f  the  alveolar  process  of  the  lower  jaw  makes  it  more  diffi- 
cult to  fit  single  plain  teeth  in  the  lower  than  in  the  upper  jaw. 


Imc.   590 


Typical  upper  and  lower  jaw. 


Fk;.   600 


Showing  the  occlusal  surfaces  of  the  upper  teeth.     (From  same  skull  as  Fig.  599.) 

Fig.  597  shows  the  alveoli  of  the  upper  denture,  Fig.  598  that  of  the 
lower. 


564 


EXTRACTION  OF   TEETH 


Fig.  601 


'■■J 


Showing  occlusal  surfaces  of  tlie  lower  teeth,      (i'roni  s:uue  skull  as  Fig.  o99.) 


Fi<i.   602 


Showing  the  buccal  surfaces  of  the  crowns  and  roots  in  position. 


SURGICAL  ANATOMY 


565 


Fig.  599  illustrates  a  typical  uj){)('r  and  lower  jaw,  the  external  sur- 
faces of  the  crowns  of  the  teeth,  also  a  normal  occlusion.  Fij^s.  (100 
and  601  illustrate  the  occluding  surfaces  of  the  teeth  and  their  relation.s 
with  each  other.    They  are  made  from  the  same  skull  as  Fig.  599. 

Fig.  602  is  from  a  photograph  taken  from  the  right  side  of  a  skull. 
It  gives  a  good  representation  of  a  fairly  normal  occlusion  of  the  teeth, 
their  shape,  roots,  and  their  relation  with  the  cancellated  tissue  and 
the  inferior  dental  canal  or  cribriform  tube  of  the  lower  maxilla.  In 
the  upper  jaw  the  bone  is  thin  over  the  position  of  the  molar  teeth,  and 
their  roots  are  comparatively  straight;  none  of  these  should  be  difficult 
to  extract.  The  buccal  roots  of  the  first  molar  are  somewhat  divergent 
from  each  other.  The  same  roots  of  the  second  molar  spread  only 
slightly,  as  they  leave  the  crown  and  close  in  at  the  points.     The  roots 


Fig.  G03 


From  the  same  jaw  as  Fig.  602. 


of  the  third  molar  are  together  and  slightly  curved  backw^ard.  In 
the  lower  jaw  the  roots  are  comparatively  straight.  Those  of  the  first 
molar  are  spread  only  a  little  apart,  this  being  the  usual  condition. 
The  roots  of  the  second  molar  are  almost  straight  and  are  nearly  parallel 
with  each  other.  The  anterior  root  of  the  third  molar  curves  slightly 
backward  until  it  joins  the  posterior  root. 

Fig.  603  is  taken  from  the  left  side  of  the  same  jaw  as  Fig.  602.  In 
Fig.  602  the  roots  have  been  exposed  down  to  their  apices;  in  Fig.  603 
only  the  external  or  cortical  plate  has  been  removed.  These  two  illus- 
trations give  a  correct  idea  of  the  relations  of  the  teeth  to  the  internal 
structures  of  the  jaw. 

Figs.  604  and  605  are  good  illustrations  of  the  relations  of  the  roots 
with  the  floor  of  the  maxillary  siiuis  usually  found  in  the  white  race. 


566 


EXTRACTIOX  OF   TEETH 


In  the  neoTO  there  is  usually  a  considerable  thickness  between  tlie 
teeth  and  the  Hoor  of  the  sinus.  It  will  be  noticed  that  the  roots  of 
the  molars  pass  u])  on  both  sides  of  the  sinus,  and  because  of  this  fact 
it  is  necessary  in  extracting  teeth  from  a  jaw  of  this  character  to  use 
the  greatest  caution,  otherwise  a  portion  of  the  floor  of  that  cavity  might 
also  be  removed.    ( )r  if  a  tooth  l)e  broken  and  nuich  upward  force  used 


Hiatus 
seniihiminari. 


Fig.  604 

Middle  ethmoidal 
cells. 


Crvstalline  lenses. 


Uncinate  process. 
LMiddle  turbinated 
buue. 
Middle  meatus. 
Maxillary  sinus. 
Inferior  meatus, 
i  11  fe  ri  or  turbinated  bone 


— Vestilmle  of  mouth. 
—First  molar. 


Distal  root  first  molar. 


Inferior  dental  nerve. 


An  anterior  \-iew  of  a  vertical  transverse  section  of  the  head,  showing  the  relations  of  the  jaws  and 
the  U-shaped  bone  of  the  mandible. 


in  endeavoring  to  take  hold  of  the  root,  the  latter  could  easily  be  forced 
into  the  sinus.  The  lower  portion  of  Fig.  604  gives  a  general  idea  of 
a  transverse  section  of  the  lower  jaw  made  posterior  to  the  mental 
foramen.  Special  attention  is  drawn  to  the  U-shaped  formation  of 
the  cortical  portion  of  the  lower  jaw  which  terminates  in  the  two  plates 
of  the  alveolar  process,  and  between  which  the  roots  are  embedded  in 
the  cancellated  tissue.     It  also  shows  how  the  roots  extend  toward  the 


SURGICAL  ANATOMY 


567 


inferior  dental   nerve,     lliere  is  no  line  of  demarcation  between  the 
alveolar  process  and  the  body  of  the  bone. 


Oms 


1st  M  1st  M 

Posterior  \-iew  of  \ertical  transverse  section  of  the  head  from  the  same  skull  as  Fig.  60-1,  showing 
the  ostium  maxillare.  which  is  indicated  on  each  side  by  a  cord  passing  through  it:  Om.  ostium 
maxillare;  1st  M,  first  molar. 


Fig.  606  shows  the  relation,  length,  and  position  of  the  second  bicus- 
pid, showing  that  its  root  is  sometimes  placed  to  the  inner  side  of  the 
anterior  root  of  the  first  molar.    The  roots  of  these  bicuspids  are  fiat,  as 


Fig.   606 


Ar  1st  M,  anterior  root  of  first  molar;  E  2d  Bi,  root  of  second  bicuspid;  Idn,  inferior  dental 
nerve;  Up,  U-shaped  or  cortical  section  of  lower  jaw. 


will  be  seen  by  looking  at  Fig.  626.    On  taking  into  consideration  their 
length,  position,  and  thinness  it  will  be  readily  seen  whv  it  is  so  often 


difficult  to  extract  them  without  breaking 


oGS 


EXTRACTIOX   OF   TEETH 


Fi(T.  007  is  taken  from  horizontal  sections  of  the  h)\ver  and  upper 
jaws,  showinif  thi-  transverse  sections  of  the  roots  of  the  teeth.  The 
section  is  made  a  httle  ahove  the  niar(,nn  of  the  alveohir  process  of  the 
upper  jaw  and  a  Httle  below  in  the  lower.     The  illustration  shows  the 


Fig.  607 

Ontr.il      I>ateral 

incisor,      incisor.        f'anine. 


m^M-'^^^^^ 


r^^. 


ucdiid  molar. 


First  molar. 


Yj  --Second  bicuspid. 


First  bicuspid. 


Horizontal  section  of  the  upper  and  lower  jaws  cut  a  little  beyond  the  free  margin  of  the  alveolar 
process,  showing  the  forms  and  position  of  the  roots  of  the  variou.s  teeth. 


shape  and  position  of  the  various  roots,  with  their  relations  to  the  pro- 
cess and  to  each  other.  Particular  attention  should  be  given  to  tlie  fact 
that  the  roots  and  process  are  in  such  close  relation  as  to  make  it  im- 
possible to  force  the  beak  of  a  forceps  between  them  without  breaking 
one  or  both  plates  of  the  process.     The  lines  leading  from  the  roots 


SURGICAL  ANATOMY 


569 


show  the  proper  (liroction   for  ;ip]>lyin^'  wluit  is  known   in  extracting 
as  the  "out-and-in  motion." 

Fig.  608  represents  a  horizontal  section  made  through  the  h)wer  jaw 
near  the  ends  of  the  roots,  and  from  the  same  bone  as  that  shown  in  the 
lower  half  of  Fig.  (507.  The  cancellated  portion  with  the  soft  tissue 
filling  the  spaces  can  be  plainly  seen.  The  nerve  passing  into  its  tube, 
the  ends  of  the  roots  of  the  second  and  third  molars,  the  tip  of  one  of 
the  roots  of  the  first  molar,  and  the  roots  of  the  first  and  second  bicus- 
pids are  all  plainly  shown.  A  little  of  the  lateral  incisor  can  be  noticed, 
but  the  centrals  do  not  reach  so  far  down. 


Fig.  608 


Re  Mi 

Horizontal  section  of  the  lower  jaw  cut  in  the  region  of  the  points  of  the  roots  of  the  teeth: 
DN,  dental  nerve;  R  3d  M,  roots  of  third  molar;  R  2d  M,  roots  of  second  molar;  R  1st  M,  distal 
root  of  first  molar;  R  2d  Bi,  root  of  second  bicuspid;  R  1st  Bi,  root  of  first  bicuspid;  Re,  root  of 
canine;  RK,  root  of  right    lateral  incisor. 


Figs.  609  and  610  are  taken  from  a  sagittal  section  of  the  upper 
jaw,  external  to  the  infraorbital  foramen,  and  through  the  roots  of  the 
molar  teeth.  This  illustration  shows  how  the  roots  often  extend  above 
the  lower  portions  of  the  floor  of  the  sinus,  an  abscess  from  the  palatal 
root  of  the  first  molar  having  discharged  into  the  floor  of  the  sinus 
at  the  point  Aa. 

It  has  been  demonstrated  both  anatomically  and  clinically  that  in- 
fectious matter  from  a  suppurating  tooth  may  eventually  give  rise  to  an 
inflammation  of  the  meninges  of  the  brain.     Should  pus  form  a  dento- 


570 


KXTRACTIOX  OF   TKKTH 


Viv..   (i()« 


Fio.   610 


Anteroposterior  (li\  ision  of  the  maxilla,  showing 
opening  of  a  dental  abscess  within  the  antrum  and 
an  infraorbital  sinus:  Us,  infraorbital  sinus;  If,  in- 
fraorbital foramen;  Pic,  piece  of  i)aper  passing 
through  infraorbital  canal;  Ms,  maxillary  sinus; 
Ar.  apical  abscess. 

Fig.  611 


<)m,  ()i)piiiiiK  into  malar  bone;  //s, 
infraorbital  .sinus. 


Longitudinal  division  of  a  mandible,  exposing  the  cancellated  ti.s.sur  in  Ihc  body  of  the  j.iw  and 

between  the  sockets  of  the  teeth. 


SURGICAL  ANATOMY 


571 


alveolar  abscess  discharge  into  the  maxillary  sinus  it  may  pass  out  into 
the  hiatus  semilunaris  and  ascend  into  the  frontal  sinus  or  in  the  vicinity 
of  the  cribriform  plate  of  the  ethmoid  through  the  infundibulum  v^hen 
the  passage  througii  the  hiatus  into  the  middle  meatus  is  small  or  con- 
stricted, as  it  usually  is  when  inflamed,  or  the  pus  may  pass  directly 
through  the  infundibulum.  Recent  research  has  shown  tiiat  the  frontal 
siiuis,  the  cribriform  plate  of  the  ethmoid,  and  the  meninges  of  the  brain 
are  in  close  relation  at  the  anterior  portion  of  the  cribriform  plate,  a  dis- 
eased condition  at  which  point  is  liable  to  involve  all  three  structures. 


Fig.   (il2 


\  V?r- 


V* 


F  G  H  I  J 

Sections  made  at  different  points  from  a  mandible  which  was  not  quite  normal  in  its  density. 


Fig.  611  is  from  a  longitudinal  section  of  the  lower  jaw,  and  gives  a 
good  idea  of  the  cancellated  tissue,  the  relations  of  the  sockets  of  the 
teeth  to  one  another,  and  the  position  of  the  inferior  dental  canal. 

Fig.  612  is  taken  from  several  transverse  sections  of  a  lower  jaw 
The  bone  is  not  quite  normal,  as  several  teeth  were  extracted  before 
death,  the  loss  having  caused  changes  in  the  character  of  the*  bone. 
Some  of  the  sections  show  but  one  canal,  while  in  others  there  are  many, 
requiring  close  observation  to  determine  in  which  the  inferior  dental 
nerve  and  vessel  have  passed. 

Fig.  613  is  taken  from  the  inner  side  of  the  right  half  of  a  lower  jaw. 
The  second  molar  has  been  broken  off,  the  roots  still  remaining  in 
position.     The  points  of  the  roots  of  the  third  molar  pass  out  through 


572 


EXTRACTION  OF  TEETH 

Fig.   (113 


A)i  uiuuiiiiuDii  iiuij;n-te<l  lower  third  molar. 
Fig.  615 


A  view  of  an  impactt'l  liw.i   iIiimI  molar. 


S  URGICA  L  A  NA  TOM  Y 


573 


the  inner  \v;ill  a  considorahle  (lislance  helow  the  myloliyoid  ridge.  A 
portion  of  the  ridoe  has  htvn  cut  away,  exposinti;  the  remainder  of  the 
internal  surface  of  the  roots.  This  will  be  further  alluded  to  when 
extraction  of  the  lower  third  molar  is  considered. 


Fig.  G16 


A  second  view  of  an  impacted  lower  third  molar,  as  shown  in  Fig.  61.5.  Part  of  the  distal  root  of 
the  .second  molar  has  been  resorbed,  exposing  the  root  canal,  more  than  likely  causing  the  devitali- 
zation of  the  pulp,  and  thus  producing  neuralgia. 


Fig.   617 


Inner  side  of  left  half  of  lower  jaw,  .showing  an  impacted  third  molar. 


Figs.  015  and  GIG  are  from  the  outer  side  of  the  right  half  of  a  lower 
jaw,  Fig.  615  showing  an  impacted  third  molar  lying  horizontally  in 


574 


EXTRACTION  OF  TEETH 


the  jaw.  Fig.  616  is  of  the  same  jaw  with  the  tooth  removed  from  its 
bed,  showing  the  inner  surface.  The  second  molar  is  a  ])ulpless  tooth 
the  distal  root  of  which  shows  where  the  impacted  tootli  has  pressed 


Fig.   018 


'•fl^Bn'*'?' 


Samp  as  Fig.  017,  with  the  impacted  molar  removed  from  his  bed. 

against  it,  causing  the  aljsorptioii  of  a  portion  of  the  root  and  exposing 
the  pulp  canal  within,  producing  death  of  that  organ.    This  must  have 

Fig.  619 


Right  half  of  lower  jaw,  showing  a  lower  third  molar  with  thickened  and  curved  roots. 


caused  neuralgia.  The  cancellated  tissue  of  this  hone,  it  will  be  noticed, 
is  not  like  that  shown  in  Fig.  603,  the  change  in  the  character  of  this 
tissue  being  the  result  of  irritation.     It  will  be  seen  that  the  roots  of  the 


SURGICAL  ANATOMY 


57; 


other  teeth  in  this  jaw  are  longer  than  usual,  the  canine  tooth  passing 
below  the  nerve  and  to  the  outer  side. 


Fig.  620 


Left  half  of  lower  jaw,  showing  a  third  molar  lying  horizontally  and  the  bone  much  more 

dense  than  normal. 

Figs.  617  and  618  represent  the  inner  side  of  the  left  half  of  a  lower 
jaw.  It  shows  an  impacted  third  molar  pointing  slightly  downward. 
The  distal  root  of  the  second  molar  is  slightly  absorbed.     On  uncover- 

FiG.   621 


Showing  two  ordinary-  impacted  lower  third  molars. 


ing  the  tooth  and  taking  it  from  its  bed,  it  was  found  to  be  incased  in  a 
thin  shell  of  bone,  as  though  the  dental  sac  had  ossified  separately  around 
this  tooth;  this  thin  incasement  of  bone  may,  however,  have  been  an 


576 


EXTRACTION  OF  TEETH 


iiifiaininatorv  product.  The  iniicr  portion  of  this  .shell  can  he  seen  in 
position.  The  nerve  and  its  accompanying  tissue  passes  into  the  infe- 
rior dental  foramen  immediately  against  the  shell,  and  has  the  appear- 
ance of  being  flattened  out.  It  divides  and  sends  a  branch  around  the 
internal  half  of  the  shell. 

Figs.  619  and  620  are  taken  from  the  right  and  left  halves  of  the 
lower  jaw.  Fig.  619  shows  the  internal  surface  of  the  right  half;  Fig. 
620  the  external  surface  of  the  same.  In  Fig.  619  the  roots  of  the 
third  molar  curve  backward,  are  joined  together,  and  are  so  enlarged 

P^iG     622 


j-ray  pioture  made  from  the  left  sifle  of  Fig.  621. 


by  an  abnormal  deposit  of  cementum,  caused  by  continued  hyperemia 
due  to  the  prolonged  irritation  that  the  form  of  each  root  is  lost;  the 
bone  also  is  much  thickened.  Fig.  620  shows  an  impacted  tooth  press- 
ing directly  against  the  one  in  front  of  it,  the  roots  of  which  have  become 
much  enlarged  by  the  deposit  of  cementum.  The  surrounding  bone 
is  also  thickened  and  much  more  compact  than  the  normal  bone.  The 
character  of  the  cancellated  tissue  of  tlu>  lower  jaw  is  lost  by  the  deposit 
of  bone  caused  by  continued  irritation  of  that  tissue. 

Figs.  625  and  626  show  the  normal  forms  of  the  teeth,  and  Fig.  627 


HUlidlCAL  ANATOMY 


577 


is  taken  from  a   n;n)nj)  of  ahiionnal   ta^th.      If  only  normal  conditions 
of  the  teeth  had  to  be  considered,  as  shown  in  Fii^s.  ()25  and  ()2(i,  extrae- 


FiG.  ()23 


Side  view  of  two  ordinary  impacted  lower  third  molars,  tiie  bone  having  been  removed  in  order 

to  expose  the  roots. 


Fig.  624 


Showing  an  inverted  lower  third  molar  erupting  into  the  subma.xillary  fossa.     (Dr.  Ottofy.^ 

37 


578 


EXTRACTION  OF  TEETH 


tion  would  be  a  very  simple  operation,  but  unfortunately  this  is  seldom 
the  case.  It  often  happens  that  even  when  the  teeth  themselves  are 
normal  they  are  situated  in  abnormal  positions,  and  for  this  reason 
alone  their  extraction  becomes  necessary.     In  fact,  so  varied  and  com- 


FiG.   625 


Deciduous  teeth — left  side.      (Burchard.) 


plicated  are  the  different  abnormalities  presented,  that  it  would  be 
impossible  to  describe  them  all.  The  diagnosis  of  unerupted  teeth  occu- 
pying abnormal  positions  has  been  greatly  facilitated  by  special  applica- 
tions of  the  skiagraphic  method.  Its  further  use  in  this  connection  is 
but  a  question  of  time  and  development.     A  careful  study  of  the  com- 


FiG.   626 


Permanent  teeth — right  side.     (Burchard.) 


plications  most  frequently  occurring  will,  however,  give  good  preparation 
for  meeting  the  emergencies. 

Figs.  613  to  624  and  628  show  abnormal  positions  of  various  teeth. 
It  will  be  readily  seen  that  no  set  of  rules  could  be  made  to  govern  the 


GENERAL  PRINCIPLES 


579 


extraction  of  these  teeth;  therefore  only  the  general  principles  govern- 
ing extraction  can  be  here  set  forth. 


Fig.  627 


Abnormalities  in  teeth. 


GENERAL  PRINCIPLES  IN  EXTRACTING  TEETH 

These  principles  may  be  classified  under  the  following  heads; 

1.  Management  and  Position  of  Patients. 

2.  Selection  of  Instruments. 

3.  Technique  of  the  Operation. 


5S()  K XT R ACTIOS  OF   TKKTIJ 

Managemant  of  Patients. — The  first  important  stop  toward  a  suc- 
cessful operation  in  dentistry  is  to  gain  the  confidence  of  the  patient, 
who  must  be  brought  to  rely  entirely  on  the  judgment  and  skill  of  the 
operator.  If  the  operator  feels  entire  confidence  in  his  own  ability  to 
carry  out  successfully  an  operation,  he  can,  by  his  manner  of  approaching 
the  patient,  impart  a  feeling  of  almost  absolute  trust  in  his  skill.  This 
feeling  of  confidence  in  himself  should  be  cultivated,  as  it  is  evident 
that  a  slight  nervousness  on  his  part,  even  though  he  be  most  skilful, 
will  tend  to  alarm  the  patient  to  such  an  extent  as  may  cause  great 
interference  with  the  operation. 

Fig.  628 


Abnormal  jaw  showing  impacted  canines. 

Position  of  the  Patient. — ^The  principal  object  to  secure  in 
placing  the  patient  is  to  obtain  a  good  view  of  the  affected  tooth  and 
contiguous  parts;  after  which  the  position  should  be  made  as  comfort- 
able as  possible  both  for  the  patient  and  operator,  taking  care  that  the 
territory  of  operation  can  be  reached  with  but  little  strain  or  effort. 

The  position  both  of  patient  and  operator  varies  slighUy  for  the 
extraction  of  each  tooth.  The  main  points  to  be  observed  are  to  have 
the  particular  tooth  to  be  operated  upon  in  view,  and  the  head  of  the 
patient  in  such  a  position  that  it  can  be  controlled  by  the  left  arm  and 
hand. 

The  chair  should  be  steady,  strong,  and  comfortable,  whh  arms  and 
a  good  head-rest  of  rather  a  concave  shape.  It  should  also  have  a  suit- 
able foot-rest.  (For  further  description  of  chair  for  anesthesia  see  page 
613.)  When  the  regular  dental  chair  is  not  obtainable,  an  ordinary 
strong  wooden  chair  can  be  used.  If  two  of  these  chairs  are  placed 
back  to  back  the  extra  one  gives  a  good  place  for  the  left  foot  of  the 
operator,  and  a  head-rest  may  thus  be  made  of  his  thigh.     The  patient 


GENERAL  PRINCIPLES  5S1 

should  be  directed  to  grasp  the  seat  at  both  sides  with  his  hands.  At 
times  it  may  be  necessary  to  extract  while  the  patient  is  in  bed  or  on 
an  operatino-  table;  in  such  cases  the  operator  must  obtain  the  best 
position  available.  Where  an  operating  table  or  couch  is  used  it  is 
well,  if  possible,  to  stand  at  the  head  of  the  couch  or  table  and  a  little 
to  one  side  of  the  patient.  By  reaching  over  the  head,  the  forceps 
shown  in  Fig.  57()  may  be  used  to  advantage  in  work  on  the  lower 
jaw;  the  same  forceps  may  be  used  for  the  upper  jaw  by  standing  to 
one  side  of  the  patient.  If  the  operator  is  ambidextrous,  so  much  the 
better,  as  it  is  very  advantageous  to  be  able  to  use  the  instrument  in  the 
left  hand,  especially  in  extracting  the  teeth  of  the  right  side  of  the  lower 
jaw;  the  operator  in  this  case  standing  on  the  left  side.  If,  however, 
only  the  right  hand  can  be  used,  the  operator  should,  as  a  rule,  stand  at 
the  right  of  the  chair,  the  left  arm  and  hand  being  used  in  various  ways 
to  control  the  head  of  the  patient.  The  mouth  is  opened  as  far  as 
necessary,  and  the  left  hand  is  then  used  to  hold  the  lips  away  and  keep 
the  jaw  as  steady  as  possible.  (See  Figs.  636  and  637.)  In  using  the 
elevator,  as  shown  in  Figs.  588  and  629,  for  the  removal  of  teeth  from 
the  left  side  of  the  mouth,  especially  for  the  lower  third  molar,  the  oper- 
ator should  stand  on  the  left  side  of  the  patient.  The  index  finger  of 
the  right  hand  should  be  placed  in  the  mouth  by  the  lingual  side  of  the 
tooth,  and  the  thumb  placed  on  the  buccal  side  of  the  first  and  second 
molars.    This  gives  steadiness  to  the  jaw  and  lessens  the  risk  of  slipping. 

Selection  and  Use  of  Instruments. — ^The  selection  of  instruments 
.depends  on  the  nature  of  the  operation  to  be  performed.  The  means 
lused  in  extraction  should  be  of  the  most  simple  character.  Many 
(deciduous  teeth  and  permanent  teeth  from  about  which  most  of  the 
process  has  been  resorbed  can  often  be  easily  extracted  with  the  thumb 
.and  finger.  Children  feel  less  apprehension  with  this  method  than  when 
an  instrument  is  used.  The  thumb  and  fingers  should  be  covered  with 
a  napkin,  and  the  thumb  placed  on  the  inner  surface  of  the  tooth  with 
the  fingers  against  the  outside  of  the  jaw.  The  tooth  is  then  forced  out- 
wardly toward  the  cheek  or  lips.  The  roots  of  the  deciduous  teeth  often 
break,  but  this  is  of  little  importance,  for  when  extraction  is  demanded 
the  roots  are  weakened  by  the  natural  process  of  resorption,  and  will  soon 
disappear.  Elevators  of  the  various  patterns  shown  in  Figs.  588,  589, 
629,  630,  and  631  should  be  used  whenever  practicable  for  removing 
roots,  and  in  some  cases  teeth  also.  Fig.  588  is  especially  useful  in 
removing  the  third  molars,  especially  if  they  be  impacted.  When  the 
internal  anatomy  of  the  jaws  is  well  understood,  this  will  be  appreciated. 

Fig.  607  shows  how  firmly  the  roots  are  embraced  at  their  necks 
ibetween  the  two  hard  plates  of  compact  tissue.  It  is  usually  impossible 
.to  force  an  instrument  between  the  roots  of  teeth  and  these  plates  with- 
out breaking  the  internal  or  external  walls  of  the  latter.  The  cancel- 
lated tissue  between  these  plates  is,  however,  soft  and  yielding,  and  into 


582 


EXTRACTION  OF  TEETH 


this  a  properlv  shaped  elevator  can  he  ])asse(l  hetween  the  roots.  After 
pushing  the  instrument  with  the  point  toward  the  root  to  he  extracted 
and  the  back  toward  the  contiguous  tooth  or  root,  using  the  hitter  as  a 
fulcrum,  revolve  the  elevator  slightly,  prying  at  tiie  same  time,  and  the 


Fig.   ()29 


Manner  of  holding  elevator  Fig.  000. 


root  will  leave  its  socket  with  little  or  no  injury  to  the  surrounding  tissue. 
Elevators  should  be  firmly  grasped  and  held  in  such  a  manner  that 
if  a  breakage  or  slip  should  occur  the  instrument  will  be  prevented 
from  wounding  the  soft  tissue.  If  root  forceps  were  used  in  cases  of 
this  kind  it  would  be  almost  impossible  to  avoid  injuring  one  or  the 


Fig.   630 


Elevator  in  use  labially. 


other  of  the  plates  when  removing  the  root.  It  is  often  advisable  to 
use  the  forceps  by  passing  the  beaks  between  the  plates  and  grasping 
the  root  on  its  proximal  surfaces,  instead  of  the  external  and  internal 
surfaces.     Even  whole  teeth  may  be  extracted  in  this  way  when  there 


GENERAL  PRINCIPLES 


583 


are  no  adjoining  teeth  or  roots.  A  similar  plan  is  sometimes  used  in 
rapid  extracting  under  nitrous  oxid,  where  roots  or  teeth  have  been 
extracted  on  each  side  of  a  tooth,  the  beaks  passing  into  the  sockets 
of  the  extracted  teeth,  thus  grasping  the  tooth  to  be  removed  on  its 
proximal  sides.  This  mode  of  operating  must  be  followed  with 
care,  especially  in  teeth  situated  below  the  maxillary  sinus,  as  the  floor 
of  that  cavity  may  be  easily  injured.    (See  Figs.  604  and  605.) 


Fig.    631 


Elevator  in  use  lingually. 

Lancing. — Lancing  for  extraction  is  not  usually  required,  although 
there  are  cases  where  it  is  quite  necessary.  If  the  teeth  have  been 
standing  alone  for  a  long  time,  especially  those  in  the  back  part  of  the 
mouth,  the  gums  are  apt  to  become  firmly  attached  to  them;  w^hen  this 
is  the  case  it  is  well  to  sever  the  connecting  tissue  by  the  use  of  the 
lancet  before  extracting.  In  extracting  roots  where  it  is  necessary  to 
remove  a  portion  of  the  external  plate  of  the  alveolar  process,  it  is  well 
to  make  an  incision  in  a  line  over  the  root,  through  the  gum  to  the 
bone;  it  is  even  advisable  to  dissect  the  gum  and  periosteum  slightly 
from  the  bone  on  each  side  of  the  cut.  This  is  done  in  order  that  the 
external  beak  of  the  forceps  may  be  passed  along  the  bone  as  far  as  de- 
sired. By  thus  lancing,  the  parts  will  afterward  come  together  and 
heal  quickly,  whereas  if  the  gum  is  cut  by  the  forceps  it  will  not  heal 
so  well.  In  extracting  roots  in  the  lower  jaw,  if  the  lancing  would 
cause  the  blood  to  cover  the  parts  and  obscure  the  operator's  view,  it 
should  be  omitted. 

Use  of  Forceps. — As  nearly  all  operators  are  right-handed,  the  instruc- 
tion as  to  the  use  of  forceps  will  be  given  with  that  understanding, 


584 


EXTRACTION  OF  TEETH 


most  of  the  special  instriiiiUMits  l)einf:^  made  for  that  liand.  The  forceps 
are  graspetl  in  the  ri^ht  hand  witli  the  j)ahn  toward  the  hody,  the  thumb 
on  top  of  and  partially  between  the  handles  (which  will  indicate  to 
a  great  extent  the  amount  of  pressure  being  exerted  uj^on  the  tooth), 
pressing  against  the  handle  nearest  the  palm  just  back  of  the  joint. 
The  first  finger  should  rest  a  little  between  the  handles,  thus  giving  a 
firmer  grip  on  the  right  handle  (Fig.  G32),  which  might  be  termed  the 
fixed,  or  passive,  handle;  while  the  other  one  is  the  movable,  or  active, 
handle.  Many  operators  do  not  place  the  first  finger  between  the 
handles  (Fig.  633).  The  second  and  third  fingers  pass  to  the  outside 
of  the  left  handle  and  are  used  to  close  the  forceps,  while  the  little 
finger  resting  between  the  handles  is  used  to  open  the  forceps,  the 
thuml)  being  used  to  force  the  l)eaks  into  the  recjuired  position.  After 
the  forceps  are  in  position  for  extracting,  the  first  finger  is  placed  along 
the  side  of  the  second  finger  to  give  more  power  to  extract. 


Fig.   632 


Use  of  forceps. 


After  it  has  been  decided  to  extract  by  using  the  forceps,  the  par- 
ticular forms  indicated  must  be  selected  and  arranged  in  a  convenient 
place,  ready  for  immediate  use  as  needed.  Especially  should  this  be 
the  case  when  the  operation  is  done  imder  the  anesthetic  influence  of 
nitrous  oxid.  It  is  under  such  conditions  that  the  fewer  forceps  used 
the  better;  the  WTiter  generally  uses  but  one  forceps  (Fig.  577)  for  the 
extraction  of  any  or  all  teeth  except  the  first  and  second  molars;  for 
those  teeth,  when  the  other  teeth  are  in  position,  he  advises  using  the 
special  forceps. 

Having  the  patient's  head  in  position,  the  forceps  are  grasped  as 
previously  described  and  the  beaks  adjusted  to  the  tooth.  As  a  rule, 
the  inner  beak  should  be  placed  in  position  first,  and  then  the  outer 
one — this  is  very  important,  especially  for  the  lower  teeth — taking  care 
not  to  include  a  portion  of  the  tongue  or  the  soft  tissues  of  the  floor 


GENERAL  PRINCIPLES 


585 


of  the  mouth,  as  hoth  are  liable  to  get  in  the  way.  When  the  forceps 
are  adjusted  to  the  inner  and  outer  surfaces  of  the  tooth,  they  should 
be  forced  between  it  and  the  gum  until  they  come  in  contact  with  the 
edge  of  the  alveolar  process.  It  is  a  common  error  of  students  to  use 
too  much  force  in  pressing  the  handles  together;  only  sufficient  force 
should  be  used  to  hold  the  tooth  or  root  securely.  The  forceps  should 
grasp  as  much  of  the  roots  as  possible,  avoiding  pressure  upon  the 
crown  and  being  careful  not  to  force  the  beaks  between  the  alveolar 
plates,  as  this  would  result  in  breaking  one  or  both  plates  over  the 
tooth  or  root  extracted  and  also  over  the  adjoining  tooth.  Cases  have 
occurred  in  which  the  entire  external  plate  of  one  side  has  been  forced 
off  in  this  way. 

Fig.  633 


Use  of  forceps. 


At  times  it  may  be  advisable  to  take  away  a  portion  of  the  outer 
plate,  in  which  case  the  lancet  show^n  in  Fig.  590  should  be  used  to  cut 
through  the  gum  a  little  beyond  the  point  of  process  to  be  removed, 
dissecting  up  the  gum  slightly;  the  inner  beak  is  then  adjusted  and  the 
outer  one  passed  between  the  divided  gum  and  the  process  as  far  as 
required;  the  forceps  should  then  be  closed  with  only  sufficient  force  to 
cut  through  the  bone  and  grasp  the  tooth,  taking  care  not  to  crush  it. 

After  the  forceps  are  in  position  the  tooth  is  loosened  by  rotating  it 
slightlv  if  it  be  a  round  conical-rooted  tooth,  such  as  a  central  incisor, 


5S()  EXTRACTION  OF  TEETH 

but  if  it  be  a  flattened  one  it  sliould  he  removed  by  an  outward  and 
inward  movement. 

Bv  the  "out-and-in  motion"  is  meant  tliat  after  tlie  foreeps  are  applied 
the  force  used  in  loosening;  teeth  is  directed  in  such  a  manner  that 
the  tooth  is  worked  outward  and  inward  from  the  median  Hue  of  the 
mouth  (see  Fig.  607,  in  which  the  hues  show  the  (hrection  of  the  motion 
for  each  tooth).  The  in(Hvi(hial  teeth  do  not  always  bear  the  same 
relation  to  the  median  line  of  the  jaw  as  shown  in  Fig.  607.  When 
the  axis  of  a  tooth  is  not  regular  it  should  be  loosened  by  moving  back- 
ward and  forward,  and  the  movement  should  be  in  line  with  its  strongest 
diameter,  which  lessens  the  danger  of  breaking  tiie  tooth. 

In  the  upper  jaw  the  inward  movement  is  made  after  the  outer,  but 
with  not  so  much  force,  as  the  structure  on  the  inner  side  is  more  dense. 

Rotation  of  a  tooth  in  extracting  is  seldom  practised,  as  the  single- 
rooted  teeth  are  usually  flattened,  and  teeth  that  have  more  than  one 
root  cannot  be  rotated.  Of  the  single-rooted  teeth,  the  upper  central 
incisors  alone  have  roots  nearly  conical  in  shape  which  permit  rota- 
tion as  well  as  the  out-and-in  motion.  A  rotary  motion  is  usually  of 
advantage  in  extracting  the  roots  of  the  upper  first  bicuspid  when  not 
double,  and  of  the  upper  molars  after  the  crowns  are  broken  away  so 
that  the  roots  are  disunited.  These  roots  are  usually  round,  conical, 
and  somewhat  curved  in  shape. 

If  possible,  the  tooth  should  be  kept  in  view  during  the  operation 
so  that  the  results  of  the  movements  may  be  seen.  A  beginner  may 
let  the  forceps  slip  and  extrac-t  the  wrong  tooth  when  he  is  not  observ- 
ing each  movement,  but  an  experienced  operator  can  tlepend  on  his  sense 
of  touch  to  a  very  great  extent.  The  amount  of  pressure  a  tooth  will 
stand  while  loosening  it  by  an  "out-and-in  motion"  depends  on  the  size, 
condition,  and  density  of  the  bony  tissue  surrounding  it  and  the  accurate 
fitting  of  the  forceps  to  the  tooth.  Experience  is  the  only  reliable  guide 
in  this  matter.  When  a  tooth  resists  ordinary  et^'ort,  if  the  operator  is 
not  quite  sure  of  the  cause  of  the  resistance  of  the  tooth,  it  is  better  to 
desist  temporarily  and  allow  the  patient  to  rest,  in  order  to  investigate 
the  condition  of  the  tooth  and  its  surroundings.  Fig.  619  will  give  some 
idea  of  the  causes  of  the  resistance  offered  by  ap|)arently  normal  crowns. 

After  the  forceps  are  applied  and  the  tooth  slightly  moved,  if  the 
operator  has  a  cultivated  sense  of  touch  he  will  feel  that  the  tooth  is 
yielding  in  one  particular  direction;  as  a  general  rule  the  tooth  should 
be  carried  in  that  way. 

The  force  applied  to  extract  teeth  safely  and  judiciously  should  be 
made  with  arm  and  wrist  motion;  if  the  whole  body  is  used  the  sense 
of  touch  is  blunted  and  accidents  are  liable  to  occur. 

Extracting  Deciduous  Teeth. — In  extracting  the  deciduous  teeth  the 
principles  involved  are  nearly  the  same  as  for  the  permanent.  A  care, 
however,  must    be    taken    that   is    not   necessary  with  the  permanent 


INDIVIDUAL  PERMANENT  TEETH 


587 


teeth,  i.  c,  to  avoid  injuring   the  developing   permanent  teeth  that  are 
situated  immediately  beneath  them. 

Fig.  634  shows  all  the  deciduous  and  the  developing  permanent 
teeth  except  the  third  molars.  It  gives  a  true  idea  of  their  relative 
positions.  Special  attention  is  drawn  to  the  position  of  the  crowns 
of  the  bicuspids  as  related  to  the  deciduous  molars.    This  is  also  well 

Fig.  634 


Skull  of  a  child,  about  six  years  of  age,  showing  all  the  deciduous  teeth  in  position  and  nearly  all 

the  developing  teeth. 

shown  in  radiogram  Fig.  648.  It  will  be  seen  that  they  are  situated 
between  the  roots  of  the  latter  teeth,  and  by  using  undue  force  in  adjust- 
ing the  forceps  these  crowns  could  easily  be  misplaced,  extracted,  or 
injured. 

If  the  deciduous  teeth  are  extracted  at  the  proper  time  they  can 
usually  be  removed  by  the  thumb  and  fingers  as  described.  If  not,  one 
of  the  forceps  shown  in  Figs.  576  and  577  should  be  used. 


EXTRACTION  OF  INDIVIDUAL  PERMANENT  TEETH 


The  anatomy  of  the  individual  teeth  and  the  majority  of  their  often- 
repeated  variations,  as  well  as  the  general  principles  governing  the 
extracting  operation  being  understood,  the  extraction  of  each  tooth  will 
now  be  studied,  those  of  the  upper  jaw  being  first  considered. 

The  Upper  Teeth. — The  Central  Incisor. — This  tooth  has  a  strong, 
round  conical  root.     The  forceps  are  carried  into  position  by  placing 


588  EXTRACTION  OF  TEETH 

the  inner  beak  at  the  pahital  surface  of  the  neck  of  the  tooth;  the  outer 
one  is  then  placed  in  position  and  die  instrument  forced  upward  with 
a  shght  rotary  motion  between  the  gum  and  the  tooth  until  it  comes 
in  contact  with  the  alveolai-  process.  As  the  root  is  round  and  conical, 
it  is  loosened  by  rotation  and  the  out-and-in  motion  and  then  removed 
by  drawing  it  directly  from  its  socket.    It  is,  as  a  rule,  easily  extracted. 

The  Lateral  Iiwiscn-. — This  tooth  is  much  smaller  than  the  central. 

The  root  is  flattened  and  somewhat  curved,  the  apex  being  often  bent 

in  the  direction  of  the  canine  teeth.    After  applying  the  forceps  as  directed 

ff)r  the  central  incisor,  the  motion  should  be  outward  and  inward.     As 

the  tooth  has  a  delicate  root,  the  force  used  must 

Fig.  635  [jg  light.    When  loosening  and  removing  it,  care 

r"        must    be   exercised,   as   its    root   is   not   straight. 

The  tooth  is  carried  in  the  direction  of  the  least 


fi 


^^^  resistance,   which  is   usually    toward  the  canine 

]  tooth. 

^       •         ^        '^~.y'        TJie  Canine. — This  tooth  is  usually  more  firmly 

(   nin.    1  tprai,  and  cen-  s^t  iu  the  jaw  than  any  other,  and  it  often  requires 

trai  incisor  extracted  from  considerable  forcc   to  break  up  its  attachments. 

maxillary    sinus    that    were     ,.^,  ,     .       ,  i        i-    i   ii        u    ^^  l  \  f j. 

causing  neuralgia.  The  Toot  IS   long   and   slightly  fiattened.     After 

applying  the  forceps  its  attachments  are  broken 
up  by  the  out-and-in  motion.  After  loosening  it  is  usually  easily  re- 
moved from  its  socket.  As  this  tooth  is  erupted  after  the  adjoining 
teeth  are  in  position,  it  is  often  malpo.sed.  If  the  deciduous  canine  has 
been  lost  before  its  proper  time,  and  the  first  bicuspid  has  pushed 
forward,  there  is  no  room  for  the  canine  to  take  its  true  position.  This 
irregularity  varies  to  a  great  extent.  The  canine  may  also  be  out  of 
position  from  unknown  causes.  A  marked  specimen  is  seen  in  Fig. 
628,  where  both  canines  are  impacted.  They  were  entirely  covered  by 
a  bony  lamina.    (See  also  Fig.  644.) 

Sometimes  the  roots  of  these  teeth  project  into  the  maxillary  sinus, 
or  even  into  the  nasal  chamber,  while  the  crowns  are  impacted  be- 
tw^een  the  palatal  plate  and  the  plate  forming  the  floor  of  the  nose. 
Fig.  635  represents  a  canine,  lateral  and  central  incisor,  which  were 
extracted  from  the  sinus,  the  roots  being  embedded  in  its  inner  wall. 
Teeth  thus  impacted  are  often  a  source  of  trouble  in  various  ways, 
and  when  discovered  should  be  removed.  When  the  tooth  is  so  covered 
by  bone  that  the  forceps  cannot  be  applied  the  bone  must  be  cut  away 
sufficiendy  to  allow  the  forceps  to  grasp  it.  A  very  good  instrument 
for  removing  the  bone  in  the  upper  jaw  is  the  elevator  shown  in  Fig.  588; 
after  the  point  has  been  sharpened  it  may  be  used  as  a  chisel  or  gouge. 

The  Bicuspids. — ^^Fhe  first  bicuspid  usually  has  a  bifurcated  root, 
and  the  only  motion  that  can  be  used  safely  for  loosening  is  the  out-and- 
in,  as  these  roots  are  sometimes  considerably  divergent.  The  removal 
after   loosening    is    not    always   easily   accomplished,    a   little   outward 


INDIVIDUAL  PERMANENT  TEETH  589 

pressiiir  hein^'  frequently  ntx-essaiy.     If  the  force  recjuired  is  used  too 
suddenly  the  inner  root  is  liable  to  break. 

The  second  hicus'pid  usually  has  a  sing'le  flattened  root,  though  occa- 
sionally it  is  bifurcated.  The  motion  used  to  loosen  this  tooth  is  the 
outward  and  inward,  using  the  same  precaution  as  with  the  first  bicus- 
pid on  account  of  the  possibility  of  a  double  root. 

Fia.  636 


Showing  position  for  extracting  upper  teeth  of  left  side. 

The  First  and  Second  Molars. — ^These  teeth  are  nearly  similar,  having 
three  roots,  two  buccal  and  one  palatal,  which  vary  so  much  in  degrees 
of  separation  that  no  set  rule  can  be  given  for  their  extraction.  The 
roots  of  the  first  are  usually  more  divergent  than  those  of  the  second. 
Only  the  out-and-in  motion  can  be  used,  rotation  being  out  of  the 
question  in  loosening  them,  as  the  roots  often  diverge  to  a  great  extent. 


590 


EXTRACTION  OF   TEETH 


(See  Fi<>-.  (527,  p.)  After  the  tooth  has  been  loosened  there  is  at  times 
a  difficuhy  in  removing  it,  on  account  of  the  (Hstance  around  the  three 
roots;  owin*;  to  their  divergence  this  distance  is  greater  than  the  size 
of  the  anatomical  neck  of  the  tooth  corresponding  to  the  opening  of  the 
socket.  The  only  general  rule  that  can  be  given  is  to  carry  it  in  the 
direction  of  the  least  resistance.  Each  tooth  has  more  or  less  of  an 
individual  character,  and  therefore  the  operator  must  l)e  governed  by 
circumstances.  The  main  precaution  to  be  observed  is  not  to  be  in  too 
great  haste,  as  there  is  danger  of  breaking  one  of  the  roots  or  removing 
a  large  piece  of  the  outer  plate  of  the  alveolar  process.  (See  Accidents, 
p.  606.) 

Fig.  637 


Showing  position  for  extracting  upper  teeth  of  right  side. 


The  Third  Molar. — This  tooth  so  varies  as  to  the  shape  and  number 
of  its  roots  that  it  is  seldom  spoken  of  as  an  abnormal  tooth,  no  matter 
in  what  form  or  position  it  may  be  found ;  the  greater  number  have  roots 
curved  backward  and  outward.  Their  position  in  the  jaw  also  varies 
considerably.  The  forceps  shown  in  Fig.  576  is  the  instrument  to  use 
in  extracting.  After  the  forceps  have  been  firmly  placed  the  principal 
motion  is  the  out-and-in,  though  more  out  than  in.  If  there  is  much 
resistance  the  hand  should  be  carried  outward  and  upward,  or  in  the 
direction  of  the  least  resistance.  This  tooth  is  sometimes  erupted  at 
the  side  of  the  alveolar  process  (Fig.  638),  with  its  occlusal  surface 
pointing  toward  the  cheek.  (See  Figs.  645  and  646,  radiograms  made 
from  the  specimen  shown  in  Fig,  638.)    It  is  not  well  to  have  the  mouth 


INDIVIDUAL  PERMANENT  TEETH 


591 


opened  too  far,  as  it  brings  the  coronoid  process  of  the  lower  jaw  in  the 
way. 

In  stating  the  general  rules  of  extracting,  caution  was  given  not  to 
make  the  movements  faster  than  could  be  seen;  this  applies  very  par- 
ticularly to  the  third  molar.  It  is  so  near  the  ascending  ramus  in  the 
lower  jaw  that  it  is  possible,  especially  when  the  roots  are  curved  and 
spread  out,  to  fracture  this  angle,  or  in  the  upper  jaw  the  tuberosity  may 
be  broken  away,  thus  opening  into  the  maxillary  sinus.  The  gum  tissue 
often  adheres  to  the  posterior  portion  of  this  tooth;  when  this  hap- 
pens it  is  best  to  desist  from  attempts  at  extraction  and  sever  the  tissue 
from  it  with  a  curved  lancet  or  scissors  before  removing  the  tooth  with 
the  forceps,  or,  as  before  advised,  dissect  the  gum  away  before  applying 
the  forceps. 

Fig.   638 


An  impacted  upper  third  molar.     A  similar  condition  found  on  the  opposite  side  of  the  skull. 


The  Lower  Teeth. — As  a  rule,  the  teeth  of  the  lower  jaw  are  more 
difficult  to  extract  than  are  those  of  the  upper  jaw,  the  lips  and  cheeks 
being  in  the  way.  The  tongue  is  also  troublesome,  covering  the  tooth, 
and  when  the  inner  beak  of  the  forceps  is  placed  in  position  special 
care  must  be  used  to  prevent  part  of  the  tongue  or  floor  of  the  mouth  from 
being  caught  in  the  instrument. 

The  Oral  or  Anterior  Teeth. — (For  position  see  Fig.  639.) — These  six 
teeth  have  small  single,  straight,  compressed  roots.  Their  extraction 
is  only  necessary  when  they  become  loosened  by  accident  or  from 
disease,  or  when  it  is  necessary  to  clear  the  mouth  for  inserting  artificial 
teeth.  The  operator  should  stand  a  little  back  and  to  the  right  side  of 
the  chair,  being  somewhat  elevated  above  the  usual  position.  Pass  the 
first  finger  of  the  left  hand  between  the  lips  and  the  alveolar  border, 
and  place  the  remaining  fingers  beneath  the  chin  with  the  thumb  on 
the  inside  of  the  teeth.     For  the  incisors  use  the  lower  root  forceps 


592  EXTRACTION  OF   TEETH 

shown  in  Fig.  587  or  the  universal  forceps  shown  in  Fig.  577.  The 
canines  are  larger  and  more  firmly  set;  delicate  root  forceps,  therefore, 
are  not  u.sually  suital^le;  the  instrument  shown  in  Fig.  577  or,  better, 
the  bicuspid  forceps  ( Fig.  585)  are  much  to  be  preferred.  An  out-and-in 
motion  is  proper  for  loosening  all  these  teeth. 

Fig.  039 


Showing  position  for  extracting  lower  anterior  teeth. 

The  Bicuspids.— The  lower  bic-uspids  have  compressed  roots  seldom 
bifurcated,  and  are  generally  extracted  by  the  out-and-in  motion.  The 
special  forceps  for  these  teeth  should  be  made  so  that  they  grasp  a  con- 
siderable portion  of  the  surface  of  the  tooth.  These  teeth  are  often 
difficult  to  extract  without  breaking  when  all  the  teeth  are  in  position, 
the  roots  being  long  and  narro\\-  and  often  situated  in  an  awkward 


INDIVIDUAL  I'ERMANENT  TEETH 


593 


position.  As  shown  in  Vl^]^.  (iOli,  tlic  ])()siti()n  of  llic  roots  of  the  second 
hicuspiil  is  a  httle  to  tlie  inner  side  of  the  anterior  root  of  the  first  molar. 
The  tooth  illustrated  in  this  particular  case  would  be  very  difficult  to 
extract  without  breaking. 

The  Firsf  Molar. — (For  position  see  Fig.  ()4()  for  the  left  side,  641  for 
the  right  side.) 

The  first  molar,  if  in  a  mouth  where  all  the  teeth  are  in  position,  is 
generally  the  most  tiifhcult  of  all  the  teeth  to  extract.  The  roots  are 
usuall}'  long  and  diverging.  It  is  lower  in  the  arch  than  the  other  teeth, 
and   is  in  fact  similar  to  an   inverted  keystone;   consequently,   when 

Fig.  640 


Showing  position  for  extracting  lower  teeth  on  the  left  side. 


extracted  it  is  drawn  through  the  arch.  When  the  teeth  are  close  together 
the  second  bicuspid  and  second  molar  yield  a  little,  but  great  care 
must  be  taken  that  one  or  both  of  these  teeth  are  not  extracted  wdth 
the  first  molar.  In  placing  the  forceps  on  the  lower  molars  the  points 
of  the  beaks  of  the  special  molar  forceps  (Fig.  573  or  586)  are  placed 
in  between  the  roots  on  each  side  of  the  tooth.  Care  should  be  exer- 
cised to  avoid  including  a  portion  of  the  tongue  or  soft  tissues  of  the 
floor  of  the  mouth  in  the  forceps.  If  the  forceps  are  not  well  placed 
the  wrong  tooth  may  be  extracted,  as  it  is  possible  for  them  to  slip  in 
between  two  teeth. 
38 


594 


EXTRACTION  OF  TEETH 


In  loosening  these  teeth  the  out-and-in  motion  is  used,  and  as  thev  are 
wedged  in  it  is  often  necessary  to  contiiuie  this  motion  while  extracting 
them  from  their  sockets.  At  times  it  is  advisable  to  move  the  tooth  out- 
wardly after  it  has  been  slightly  lifted  from  its  socket.  Occasionally  the 
roots  diverge  so  far  that  either  the  crown  has  to  be  broken  from  the 
roots  at  their  bifurcation  or  the  tooth  divided  in  the  line  of  bifurcation 
with  splitting  forceps;  each  root  being  then  extracted  separately. 

The  Second  Molar. — The  roots  of  this  tooth  are  not  as  diverging 
as  those  of  the  first  molar,  as  may  be  seen  by  examining  Fig.  002,  nor  is 
the  tooth  wedged  in  as  tightly  as  in  the  case  of  the  first  molar. 

The  out-and-in  motion  is  recjuired  for  these  teeth,  using  the  same 
precautions  that  are  necessary  in  the  extraction  of  the  first  molar. 

Fig.  641 


Showing  position  for  extracting  lower  teeth  of  the  right  side. 


The  Third  Molar. — In  this  tooth  the  roots  may  vary  so  much  in 
number  and  shape  that  it  can  hardly  be  said  to  be  a  typical  third  molar. 
Fig.  002  shows  what  might  be  called  a  typical  third  molar,  but  these  are 
only  found  in  well-developed  jaws,  where  the  teeth  are  not  so  large  as 
to  cause  crowding,  or  where  there  has  been  no  inflammatory  condition 
causing  excessive  deposit  of  lime  salts  within  the  cancellated  tissue. 
Thev  vary  in  character  from  the  one  shown  in  Fig.  602  to  those  shown 
in  Figs.  613  to  624  inclusive.    There  are  also  third  molars  having  three, 


INDIVIDUAL  PERMANENT  TEETH  595 

four,  or  five  roots.  In  Fig.  027,  a  shows  another  form  of  the  third  molar; 
h,  c,  (I,  c,  and  /  show  where  the  third  rnolar  has  luiited  with  the  second 
mohir;  c/  and  //.  ilhistrate  three  molars  united;  i,  j,  k,  I,  m,  n,  o,  and  p 
show  variations  of  roots.  The  positions  these  teeth  occupy  may  vary 
in  all  degrees  from  that  shown  in  Fig.  602  to  those  shown  in  Figs.  613 
to  624  inclusive. 

Where  the  third  molar  is  in  the  position  shown  in  Fig.  C02,  and  there 
are  no  other  complications,  its  extraction  is  easy.  The  tooth  is  removed 
by  placing  either  the  special  lower  molar  forceps  shown  in  Fig.  586  or 
the  forceps  shown  in  Figs.  576  and  577  in  position,  and  using  the  out- 
and-in  motion  with  a  slight  raising  of  handles.  If  Fig.  576  be  used  the 
beaks  should  be  turned  downward  and  the  handles  carried  upward. 
But  when  it  is  of  irregular  form  and  position,  as  shown  in  the  various 
illustrations,  the  difficulty  increases  with  the  degree  of  variance  from 
that  of  the  typical  tooth  shown  in  Fig.  602.  These  cases  should  be 
closely  studied.  If  portions  of  the  teeth  are  in  view,  as  shown  in  Figs. 
619  and  620,  they  will  assist  to  some  extent  in  the  diagnosis  of  the  posi- 
tion of  the  roots.  In  this  particular  case  the  bone  as  well  as  the  roots 
being  much  hypertrophied,  it  would  be  impossible  to  extract  the  roots 
without  fracturing  the  process  to  a  greater  or  less  extent.  It  will  be 
noticed,  on  examining  the  section  Fig.  619,  that  to  have  fractured  the 
inner  portion  of  the  jaw,  the  inferior  dental  nerve  and  vessels  and  also 
the  mylohyoid  nerve  and  vessels  would  be  endangered.  If  in  attempt- 
ing to  extract  this  tooth  it  should  not  yield  to  a  pressure  which  if  in- 
creased would  break  the  bone,  it  is  better  to  desist  and  cut  away  the  bone 
with  a  bur  (shown  in  Fig.  651)  in  the  surgical  engine,  as  was  done  in  the 
case  of  the  specimen  from  which  the  illustration  was  made. 

The  Extraction  of  Malformed  and  Abnormally  Placed  Teeth. — The 
term  "  impacted  teeth"  is  generally  used  to  designate  permanent  teeth 
which  are  abnormally  placed  or  have  failed  wholly  or  partially  to  erupt. 
It  is  also  sometimes  employed  to  indicate  the  retarded  eruption  of 
deciduous  teeth. 

Order  of  Frequency  of  Abnormally  Placed  Teeth. — The  experience  of 
the  writer  has  been  that  the  order  of  frequency  of  impacted  teeth  is 
as  follows:  First,  the  lower  third  molar;  second,  the  upper  canines; 
third,  the  upper  third  molar;  fourth,  the  upper  central  incisor;  fifth, 
the  lower  second  premolar;  sixth,  the  upper  second  premolar;  seventh, 
the  lower  canine. 

Diagnosis. — Many  malformed  and  abnormally  placed  teeth  are  entirely 
hidden  from  view,  and  those  in  which  the  crowns  are  partially  seen 
give  only  a  suggestion  of  the  cusps  while  the  shapes  and  positions  of  their 
roots  are  difficult  to  diagnosticate.  In  order  that  the  extraction  may  be 
intelligently  made,  a  forty-five  degree  angle  hatchet-shaped  excavator  is 
one  of  the  most  useful  instruments  to  use  as  a  probe  to  determine  the 
position  of  the  crowns  and  roots,  especially  when  used  by  one  experienced 


59G  EXTRACTION  OF   TEETH 

in  the  liandlinc;  of  such  an  instrument  and  wlio  is  thoroufjhly  conversant 
with  the  normal  and  patliological  anatomy  of  tliese  parts.  No  one  with- 
out this  knowledge  is  properly  equipped  to  diagnosticate  such  malposed 
teeth,  much  less  to  extract  them. 

The  improvement  of  radiography,  especially  in  the  technicpie  of  its 
dental  application,  has  been  so  rapid  and  its  results  so  accurate,  that 
the  use  of  the  a:-ray  in  the  diagnosis  of  impacted  teeth  has  become 
indispensable,  especially  in  cases  where  none  of  the  tooth  is  exposed  to 
view. 

Figs.  614  to  624  inclusive  are  made  from  photographs  showing  some 
of  the  positions  in  which  lower  impacted  third  molars  are  found.  These 
illustrations  were  made  from  cleaned  specimens.  Fig.  638  shows  the 
crown  of  an  impacted  upper  third  molar  where  a  portion  of  the  bone  has 
been  removed. 

Fig.  642 


Radiogram  of   mandible,  showing  rudimentary  fourth  molar 

Fig.  622  is  made  from  a  radiogram  of  both  halves  of  the  bone  of  the  same 
boiled  or  cleaned  mandible.  It  shows  two  deformed  and  misplaced 
lower  third  molars.  In  the  upper  picture  the  tooth  is  nearly  in  a  hori- 
zontal position  with  its  occluding  surface  well  "  locked"  under  the 
posterior  surface  of  the  second  molar.  It  will  be  noted  that  the  roots 
are  curved  upward  and  backward  above  the  inferior  dental  canal  or 
tube.  The  roots  of  the  second  and  third  molars  are  enlarged  by  the 
irritation  resulting  in  the  overactivity  of  the  cementoblasts,  die  crown 
of  the  second  molar  is  tipped  backward,  probably  from  the  pressure 
of  the  anterior  cusp  of  the  third  molar.  In  the  lower  picture  the  third 
molar  seems  to  be  in  line  to  take  its  proper  place  but  its  anterior  cusps 
are  caught  under  the  crowns  of  the  second  molar  and  the  solid  bone 
posterior  to  it  prevents  it  from  taking  its  normal  position;  the  roots 
of  this  third  molar  extend  below  the  line,  and  to  the  lingual  side,  of  the 


INDIVIDUAL  PERMANENT  TEETH  597 

inferior  dental  canal  or  tube.  The  roots  of  the  tliree  molars  are  enlarged 
by  an  extra  deposit  of  cementum. 

Fig.  642  is  made  from  a  radiogram  of  a  cleaned  specimen,  which  shows 
an  impacted  rudimentary  lower  fourth  molar  The  roots  of  the  second 
and  third  molars  are  thickened,  the  surrounding  tissue  being  more 
dense  than  normal.  These  conditions  are  difficult  to  diagnosticate  in  the 
living  subject  and  are  best  revealed  by  a  good  radiographic  plate 

Fig.  643  is  made  from  a  radiogram  of  a  cleaned  specimen  which  shows 
a  lower  tooth  in  the  ramus  of  the  jaw. 

Fig.  644  is  made  from  a  radiogram  of  a  cleaned  skull  which  shows  an 
impacted  upper  right  canine  tooth  lying  across  the  roots  of  the  central 
and  lateral  incisors,  also  in  close  juxtaposition  to  the  roots  of  the  first 
and  second  premolars.  The  end  of  the  canine  root  is  in  the  wall  of  the 
maxillary  sinus. 

Figs.  645  and  646  are  two  pictures  made  from  radiograms  of  a  cleaned 
skull  (see  Fig.  638).  They  show  two  impacted  upper  third  molars, 
one  on  each  side  of  the  jaw.  Fig.  645  shows  them  apparently  in  close 
relation,  while  in  Fig.  646  they  are  wide  apart.  The  cause  of  this  apparent 
difference  of  position  is  that  in  the  first  picture  the  teeth  on  the  opposite 
sides  of  the  jaw  are  nearly  in  a  line  with  the  anode  or  target  of  the 
a;-ray  tube,  while  in  the  second  picture  the  tube  is  placed  a  little  farther 
back,  causing  the  impacted  tooth  and  the  teeth  nearest  that  side  to  be 
thrown  forward,  apparently  placing  the  impacted  tooth  in  the  maxillary 
sinus.  It  requires  some  practice  to  read  correctly  pictures  of  this  kind 
and  avoid  an  error  of  diagnosis  due  to  an  optical  illusion  such  as  that 
shown  in  the  case  here  illustrated,  the  teeth  that  show  most  distinctly  are 
those  that  are  nearest  the  plate  when  the  radiogram  was  taken.  When 
there  is  an  impacted  tooth  or  teeth  in  each  side  of  the  jaw  it  is  necessary 
to  take  two  pictures,  one  radiogram  placing  the  plate  on  the  right  side 
and  another  one  with  the  plate  on  the  left  side.  In  film  pictures  the 
confusion  of  the  sides  is  avoided,  but  it  is  almost  impossible  to  obtain  a 
radiogram  on  a  film  of  so  highly  placed  impacted  teeth  as  in  this  case. 

Fig.  647  is  made  from  a  radiogram  of  a  patient,  showing  a  rather 
common  case  of  impacted  lower  third  molar,  also  an  upper  right  molar 
that  has  not  erupted  into  its  normal  position.  When  the  plate  of  this 
picture  is  carefully  examined  there  is  shown  to  be  a  condition  in  the 
opposite  side  similar  to  those  shown  in  Figs.  645  and  646,  which  made 
it  necessary  to  have  another  plate  made  to  give  a  clearer  view  of  the 
other  side  of  the  jaw. 

Fig.  648  is  made  from  a  radiogram  of  a  patient  about  the  age  of 
ten.'  This  picture  shows  the  lack  of  development  of  the  lower  left 
second  and  third  molars;  it  also  shows  that  the  upper  second  molar  is 
in  a  false  position  with  no  germ  of  the  third  molar  showing.  The  decid- 
uous premolars  are  shown  immediately  over  the  permanent  premolars, 
bicuspids,   which  demonstrate  that  in  extracting  deciduous  teeth  the 


598 


EXTRACTIOX  OF  TKKTII 


forceps  iiiust  not  he  forced  down  helow  the  crow  lis.    The  same  conditions 
are  shown  in  Fii£.  ()34. 


Fii..  043 


Showing  tooth  malposed  in  ramus  of  the  mandible. 
Fic.   644 


Radiogram  showing  impacted  canine. 


INDIVIDIAL  PERMANENT  TEETH 


599 


Radiogram  showing  impacted  third  molars. 


Fig.  646 


Same  case  as  Fig.  645,  taken  from  different  angles 


600 


EXTRACT  I  ON  OF   TEETH 


Fig.  049  is  made  from  a  radioifram  film,  it  shows  a!i  impacted  lower 
third  mohir.  Tiiis  tooth  is  in  sueh  a  position  that  its  oechidinii;  surface 
can  be  cut  away  witli  a  tlisk. 

Fig.  ()5l)  is  made  from  a  radiogram  fihii;  it  shows  a  h)wer  tiiird  mohir 
impacted  below  the  second  molar,  apparently  advancing  between  the 
second  and  first  molar.  The  patient  was  suffering  not  only  in  the 
immediate  region,  but  also  in  the  surrounding  parts  of  the  temporo- 
mandibular articulation.  Extraction  of  the  first  molar  was  all  that 
was  necessary  to  produce  almost  instant  relief,  and  the  third  molar 
soon  began  to  advance  to  the  position  of  the  first. 


P"k;.   647 


Showing  impacted  lower  tliird  molar  and  malposed  upper  molar. 


Abnormally  placed  teeth  usually  gi\e  considerable  trouble,  if  not  in 
early  life,  they  do  later  on,  the  seriousness  of  this  disturbance  depending 
largely  upon  the  location  and  malformation  of  the  misplaced  tooth 
and  upon  the  general  conditions  of  the  patient.  If  left  impacted  these 
teeth  are  liable  to  prevent  the  proper  nourishment  of  other  teeth,  as 
shown  in  Figs.  615  and  628.  They  are  also  liable  to  press  upon  the 
branches  of  the  fifth  pair  of  nerves,  producing  severe  neuralgia  not  only 
in  the  locality  of  the  lesion,  but  in  remote  parts.     They  are  also  liable 


INDIVIDUAL  PERMANENT  TEETH 


601 


to  hriiiti;  about  inflainnuitory  conditions  of  this  rooion,  j)nKlucini;-  cellu- 
litis in  the  tissues  of  the  mouth,  neck,  and  throat.  They  interfere  with 
the  temporomandibular   articulation,    cause  disturbances   in   the   nasal 


Fic.    (i48 


Same  case  as  in  Fig.  647,  taken  from  a  different  angle. 
Fig.  649  Fig.  650 


Impacted  lower  third  molar. 


Impacted  third  molar  below  the  second  molar. 


cavity  and  the  associated  pneumatic  sinuses  and  cells,  and  even  interfere 
with  hearing.  They  may  even  contribute  to  the  production  of  malig- 
nant growth  of  the  bone  and  surrounding  tissue. 


()()2  EXTRACTION  OF  TEETH 

Many  cases  could  l)e  cited  where  serious  pathological  conditions  have 
been  produced,  such  as  chorea;  also  various  degrees  of  mental  disturb- 
ances, even  insanity,  which  have  been  relieved  by  the  treatment  of 
removal  of  nialposed  teeth.  The  conditions  under  which  these  teeth  are 
formed  vary  so  much  that  the  same  rules  for  extracting  under  ordinary 
circumstances  c-annot  be  applied  to  them  except  in  a  general  way. 
After  the  diagnosis  of  the  character  and  position  of  the  tooth  has  been 
made,  then  the  operation  is  to  be  planned  out.  As  a  rule,  the  offending 
tooth  should  be  removed  or  liberated  without  the  sacrifice  of  any  other 
teeth,  but  there  are  cases  in  which  other  teeth  should  be  extracted. 
There  are  several  points  to  be  considered:  The  character  of  the  tooth 
and  its  position,  the  character  of  the  adjoining  teeth,  age,  and  general 
health  of  the  patient. 

When  the  impacted  tooth  can  be  brought  into  useful  position  by  the 
removal  of  causes  impeding  its  eruption,  the  necessary  steps  should 
be  taken  for  its  liberation,  occasionally  it  will  be  found  advisable  to 
extract  teeth  other  than  the  impacted  one,  thus  allowing  the  retarded 
teeth  to  erupt  into  the  place  of  the  extracted  one.  For  example,  there 
are  cases  where  a  lower  or  upper  third  molar  will  erupt  into  the  {)lace  of 
an  extracted  second  molar.  Then  again  in  cases  similar  to  those  shown 
in  Fig.  615  and  638  one  should  not  extract  the  impacted  tooth  without 
first  extracting  the  second  molar  as  the  danger  to  the  surrounding  tissues 
and  bone  necessarily  incident  to  the  removal  of  the  impacted  tooth  is 
too  great. 

The  surgeon  must,  of  course,  save  teeth  where  he  can,  but  it  is  more 
important  to  conserve  surrounding  tissues  and  avoid  injury  to  the  jaws. 
In  other  words  where  grave  pathological  sequeUie  of  impacted  teeth  are 
present  or  imminent,  it  is  more  important  that  these  consequences  should 
be  cured  or  avoided  than  that  a  tooth  or  teeth  otherwise  useful  should 
be  retained. 

The  following  descriptions  will  cover  the  general  procedure  of  extract- 
ing ordinary  forms  of  impacted  lower  third  molars.  (See  Figs.  621,  622, 
and  650.)  If  the  teeth  are  well  up  and  the  crowns  are  exposed  so  that 
the  occluding  surface  can  be  cut  away  it  should  be  done  with  a  car- 
borundum disk,  which  will  "unlock"  the  third  molar  from  the  second, 
then  if  the  bone  overlying  the  roots  is  not  too  dense  the  tooth  can  be 
lifted  from  its  socket  by  the  use  of  an  elevator  (Fig.  58(S);  if,  however, 
the  bone  is  dense,  it  must  be  cut  away  until  the  remainder  will  yield 
to  the  pressure  from  the  elevator.  In  teeth  like  those  shown  in  Figs. 
615  and  the  upper  picture  of  612  it  would  be  impossible  to  use  the  disk 
to  unlock  the  tooth  without  injuring  the  surrounding  tissues.  In  Fig. 
615  it  would  be  advisable  to  extract  the  second  molar,  as  it  is  badly 
decayed  and  devitalized,  although  it  is  more  than  likely  that  in  this 
particular  case  the  third  molar  would  not  ascend  to  a  serviceable  position. 
In  lower  picture  (Fig.  622)  the  writer  would  recommend  the  extraction  of 


IXDIVJDLAL  PERMANENT  TEETH 


603 


Ktc.  051 


the  second  molar,  as  tliere  is  every  probability  that  the  third  molar  would 
then  become  a  useful  tooth.  In  those  cases  where  the  use  of  a  disk  will 
not  unlock  the  third  molar  and  it  is  not  desirable  to  extract  the  second, 
the  process  of  removing;  the  impacted  third  molar  becomes  a  more 
serious  operation,  and,  as  a  rule,  should  be  done  in  a  hospital,  where  all 
conveniences  and  assistances  are  at  hand,  for  the  removal  of  some 
impacted  teeth  is  more  difficult  and  serious  than 
even  some  of  the  major  operations  of  general  sur- 
gery. The  patient  should  be  etherized,  a  mouth  gag 
fixed  in  position,  and  a  portion  of  the  soft  tissue  re- 
moved with  a  small  knife;  then  using  a  revolving 
spiral  osteotome  (Fig.  651),  operated  by  the  surgical 
engine,  the  bone  covering  the  greater  porticm  of  the 
tooth  can  be  cut  away  until  the  elevator  will  lift  the 
tooth  out  of  its  bed.  It  is  sometimes  better  to  cut 
through  the  crown  or  neck  of  the  tooth  until  it  is  so 
weakened  that  when  the  elevator  is  forced  under  the 
tooth,  it  will  break  at  this  point.  This  would  allow 
each  portion  to  be  removed.  When  it  is  impossible 
to  force  the  elevator  (shown  in  Fig.  629)  between 
the  bone  and  the  tooth,  a  space  can  be  made  by 
pushing  a  revolving  osteotome  between  the  tooth  and 
the  bone,  cutting  a  portion  of  each,  which  will  make 
sufficient  opening  for  the  use  of  the  elevator. 

The  writer  now  seldom  uses  the  forceps  to  remove  a  tooth  after 
loosening  it  with  the  elevator.  In  using  the  elevator  on  the  left  side,  it  is 
operated  with  the  right  hand,  the  surgeon  standing  on  the  left  side  of  the 
patient.  The  left  forefinger  is  placed  in  the  mouth,  by  the  lingual  side 
of  the  tooth,  and  the  thumb  is  placed  on  the  buccal  side  of  the  first  and 
second  molars.  This  gives  steadiness  to  the  jaw  and  lessens  the  risk 
of  slipping.     As  the  tooth  is  raised  from  its  socket,  the  forefinger  is 


Two  forms  of  Cryer's 
spiral  osteotome. 


Fig.  652 


Showing  three  views  of  a  lower  three-rooted  molar  tooth. 


placed  so  as  to  bring  the  tooth  out  of  the  mouth.  If  the  tooth  to  be 
removed  is  on  the  right  side,  the  elevator  should  be  used  with  the  left 
hand  if  possible  (the  surgeon  standing  on  the  right  side).  If  the  operator 
must  use  the  elevator  with  his  right  hand,  he  should,  however,  manage  to 
guard  and  steady  the  parts  with  his  left  hand. 

Fig.   652  is  made  from  three  photographs  of  a  lower  three-rooted 


604 


EXTRACTION  OF  TEETH 


molar  tooth  after  extraction.  A  shows  the  outer  or  hiiccal  side  of  its 
roots,  in  about  the  same  position  as  when  in  the  jaw.  The  {posterior 
cusps  were  broken  away  in  a  former  en(h'a\ or  to  extract  it.  The  greater 
portion  of  the  crown  was  cut  away  with  the  surgical  engine.  C)n  the 
side  of  the  tooth  there  is  a  groove  extenchng  backward,  dcnvnward, 
and  inward,  cut  by  tiie  osteotome.  It  was  along  this  groove  that  the 
elevator  was  forced  under  the  tooth,  causing  the  slight  remaining  ])ortion 
of  the  crown  to  fracture.  In  Z^  the  tooth  is  tin-ned  slightly  outward,  in 
order  to  show  three  roots  and  the  line  of  fracture  which  liberated  the 
tooth.  In  C  the  tooth  is  turned  upon  its  buccal  surface,  showing  the  two 
anterior  cusps  which  were  locked  under  the  distal  surface  of  the  second 
molar. 

Fig.  653 


Showing  the  direction  in  whirh  the  lower  third  mohir  i>i  to  he  extracted. 


In  Fig.  013  the  third  molar  is  in  such  position  as  to  be  easily  extracted, 
though  if  proper  care  were  not  used  the  extraction  might  have  serious 
consecjuences.  It  will  be  noticed  that  the  points  of  the  roots  are  just 
through  the  inner  U-shaped  cortical  portion  of  the  lower  jaw  below 
the  mylohyoid  ridge  and  project  into  the  submaxillary  region.  Now, 
should  this  tooth  or  the  roots  y>e  pushed  downward  in  attempted  ex- 
tracting, as  is  sometimes  taught,  it  might  be  forced  into  the  submaxillary 
region  and  consequently  be  lost  for  a  time,  with  the  possil)ility  of  having 
to  perform  a  subse(|uent  surgical  operation  to  cut  it  out  from  the  neck. 

An  impacted  third  molar  often  causes  great  distress  by  initiating  an 
inflammation  which  extends  to  the  region  surrounding  the  angle  of  the 
jaw,  and  often  including  the  temporomaxillary  articulation  and  soft 
parts  within  the  mouth.  Under  these  ccMiditions  the  jaws  can  only  be 
partly  opened,  deglutition  is  impaired,  and  solid  food  cannot  be  taken. 
If  any  part  of  the  tooth  can  be  seen,  the  difficulty  is  not  so  great.  Relief 
must  be  given,  and,  as  a  general  rule,  the  offending  tooth  should  be 
extracted.    Circumstances  may  arise  in  which  the  removal  of  the  second 


TREATMENT  AFTER  EXTRACTION  605 

molar  may  become  an  luiavoidahle  preliminary  to  the  removal  of  the 
third  molar.  As  the  mouth  can  only  be  opened  slightly,  it  i.s  impossible 
to  use  the  larp;e  special  molar  forceps.  An  elevator  is  sometimes  recom- 
mended in  these  cases,  but  it  may  prove  to  be  a  dangerous  instrument 
to  use  under  such  conditions,  for  when  the  tooth  is  lifted  out  of  its  posi- 
tion in  the  mouth,  it  might  slip  back  into  the  larynx.  It  is  well  in  some 
cases  to  loosen  a  tooth  with  an  elevator  and  then  remove  it  with  the 
forceps  shown  in  Figs.  576  or  577,  as  they  are  small,  and  are  so  shaped 
that  the  beaks  may  be  carried  back  to  the  tooth  mainly  along  the  vesti- 
bule of  the  mouth,  the  inner  blade  being  placed  between  the  teeth  by 
passing  the  forceps  back  of  the  second  molar.  Often  it  is  impossible 
to  see  completely  what  is  being  done;  therefore  it  is  not  well  for  a  beginner 
to  undertake  this  kind  of  extracting.  After  the  forceps  are  in  position 
the  tooth  should  be  worked  in  any  direction  in  which  it  will  yield;  this 
is  generally  outward,  upward,  and  backward,  in  the  manner  of  unfasten- 
ing a  hook  (Fig.  653).  When  the  lower  third  molar  is  impacted  near 
the  gonion  or  external  angle  of  the  jaw,  it  may  be  necessary  to  open  it 
from  the  outside  through  the  soft  tissues.  When  such  is  the  case  the 
surgical  engine  should  be  used  for  cutting  the  bone. 


TREATMENT  AFTER  EXTRACTION 

The  operator  should  recognize  immediately  any  accident  that  may 
have  happened  during  the  operation  of  extraction,  and  treat  it  as  the 
circumstances  indicate;  but  if  nothing  unusual  occurs,  then  the  patient 
may  be  allowed  a  few  moments'  rest,  after  which  the  mouth  should  be 
carefully  examined.  If  there  be  any  loose  portions  of  the  process  or 
pieces  of  gum  hanging  to  the  parts  operated  upon,  they  should  be 
removed  by  any  convenient  means,  such  as  small  forceps,  a  curved  pair  of 
scissors,  or  a  curved  lancet  (Figs.  590  and  592). 

When  several  teeth  have  been  extracted,  leaving  ragged  edges  of  the 
outer  walls  of  the  alveolar  process,  these  should  be  removed  with  the 
excising  forceps,  or,  better  still,  by  the  use  of  either  forceps  Fig.  576  or 
577,  according  to  circumstances,  as  the  beaks  can  be  carried  between  the 
gum  and  the  process  better  than  can  the  blades  of  the  excising  forceps. 

An  antiseptic  mouth  wash,  consisting  of  a  tablespoonful  of  phenol- 
sodique  to  a  glass  of  water,  should  be  used  several  times  daily  for  the 
next  few  days.  Any  other  suitable  antiseptic  mouth  wash  which  may 
be  more  agreeable  to  the  patient  may  be  used  instead,  although  the 
phenol-sodique  is  highly  efficacious. 

Occasionally,  in  a  few  days  after  extraction,  pain  will  be  noticed  in 
and  about  the  alveolus,  especially  when  the  tooth  has  been  the  seat  of 
pericemental  inflammation.  Relief  in  such  a  case  is  usually  given  by 
removing   any  clot   that   may   have  formed,  and   breaking   down  the 


606 


EXTRACTION  OF  TEETH 


degenerated  tissues  wliich  should  have  adhered  to  the  root.  A  pledget 
of  cotton  saturated  with  the  full-strength  solution  of  j)henol-sodi(iue  or 
cainpho-pheni(iue  should  then  be  inserted  as  a  dressing. 


ACCIDENTS 


When  accidents  of  any  kind  whatever  occur,  the  operator  should  be 
calm  and  appear  perfect  master  of  the  situation.  He  should  be  pre- 
pared to  deal  successfully  with  whatever  conditions  may  arise. 


Vie.,   li.54 


Fir;.  655 


Fig.  656 


Fig.  657 


Fig.  658 


Fig.  659 


Fig.  660 


Fig.  661 


Fig.  662 


One  of  the  most  common  accidents  is  the  breaking  of  a  whole  or 
portion  of  a  tooth  or  root.  If  the  operator  has  any  doubt  of  his  ability 
to  remove  the  tooth  entire,  he  should  inform  the  patient  that  there  is  a 
possibility  of  its  breaking,  in  which  case  not  to  be  alarmed.  If  the 
tooth  is  removed  without  breakage,  so  much  the  better;  even  if  it  does 
break,  it  will  not  cause  alarm  to  the  patient.  It  is  more  desirable  that 
all  of  a  tooth  should  be  removed,  for  if  its  surrounding  membrane  has 
been  inflamed,  or  if  a  root  having  a  portion  of  the  pulp  attached  has 
been  broken,  either  will  be  the  source  of  obstinate  pain. 


ACCIDENTS  607 

It  is  better,  however,  under  some  circiinistances  to  let  certain  roots 
remain  if  they  are  broken  than  to  break  away  a  large  amount  of  process. 
Roots  are  sometimes  so  situated  that  they  may  be  easily  forced  into  the 
maxillary  sinus  (see  Figs.  604  and  605),  or  into  the  submaxillary  region 
(see  Fig.  613),  or  upon  the  inferior  dental  nerve.  If  there  exist  reasons 
for  believing  that  the  root  will  not  cause  undue  pain,  and  there  be 
danger  of  breaking  a  large  amount  of  process,  it  is  preferable  to  let  it 
remain,  as  in  a  short  time  the  contraction  of  the  soft  parts  and  their 
expulsive  efforts  will  force  the  root  outward,  and  it  may  then  be  removed 
without  danger.  If  roots  are  forced  into  the  maxillary  sinus  they  must 
be  followed  and  removed. 

When  several  teeth  are  to  be  extracted  under  an  anesthetic,  if  the 
gum  should  adhere  unduly  to  one  of  them,  the  operator  should  desist 
from  its  removal  and  proceed  with  the  other  extractions,  after  which 
the  adherent  gum  should  be  severed  with  a  curved  lancet  or  a  pair  of 
curved  scissors  and  the  tooth  then  removed.  If  the  gum  be  much 
torn  and  the  bone  exposed  to  a  great  extent,  it  should  be  held  in  place 
by  a  few  interrupted  sutures.  If,  how^ever,  proper  care  be  taken  in 
extracting,  this  should  not  occur. 

In  extracting  crowded  teeth,  or  those  having  frail  alveolar  surround- 
ings, it  is  possible  to  remove  a  piece  of  the  alveolar  plate,  especially  in 
extracting  the  first  and  second  molars,  the  broken  piece  extending  back- 
ward, forward,  or  in  both  directions  to  the  adjoining  tooth  (see  Figs. 
654  to  662).  The  tooth  in  front  may  even  be  partially  lifted  from  its 
socket.  As  soon  as  the  operator  sees  the  impending  accident  he  should 
either  stop  and  see  if  his  method  of  extraction  could  be  improved,  or, 
this  point  being  negatively  decided,  hold  the  parts  in  position  with  the 
left  hand  as  well  as  he  can,  and  after  the  tooth  is  removed  force  the 
injured  parts  into  position;  they  will  usually  stay,  but  if  not,  appropriate 
appliances  should  be  used  for  retention. 

In  extracting  the  upper  third  molar,  the  tuberosity  is  sometimes 
broken  away,  opening  into  the  maxillary  sinus  (see  Figs.  654,  655,  656, 
659,  and  662,  showing  where  teeth  have  been  carried  away  with  the 
tuberosity).  If  it  is  a  simple  fracture  the  parts  should  be  forced  into  place 
and  they  will  in  a  short  time  reunite.  But  if  the  parts  are  torn  loose  it 
will  be  of  little  use  to  try  to  replace  them;  the  best  course  is  to  trim 
away  the  ragged  edges,  using  the  curved  scissors  for  that  purpose. 

After  such  a  fracture  it  is  possible  that  hemorrhage  may  occur  from 
rupture  of  the  superior  dental  artery.  This  is  sometimes  difficult  to 
control.  One  of  the  best  remedies,  however,  is  to  pack  the  parts  tightly 
with  medicated  gauze.  This  application  must  be  left  in  for  a  few  days 
and  then  be  carefully  removed.  It  is  sometimes  well  to  take  out  only 
part  of  the  gauze  at  a  time,  the  loosened  portions  being  cut  off  with  a 
pair  of  curved  scissors.  Hemorrhage  after  extraction  usually  ceases 
in  a  short  time,  and  then  there  is  no  occasion  for  treatment;  when, 


608 


EXTRACTION  OF  TEETH 


however,  the  adjoining  parts  are  niueh  inHamed,  or  if  the  patient  is  in  an 
anemic  condition,  or  the  case  is  one  of  iieniorrhagic  diathesis,  special 
treatment  will  be  necessary. 

Hemorrhage  of  extraction  may  be  divided  into  two  classes,  arterial 
and  capillary.  When  arterial,  it  is  usually  located  in  the  socket  of 
the  tooth,  and  may  usually  be  stopped  without  much  difficulty  by  taking 
a  twist  of  absorbent  cotton,   shaping  it  into  a  thin  tapering  roll,  and 


Fi<;.  (ittS 


Barton's  head  bandage. 


Fin.   ()64 


thoroughly  packing  the  socket.  Before  inserting  the  cotton  tampon, 
it  should  be  rolled  in  tannic  acid  until  the  fibers  will  hold  no  more, 
then  the  cotton  is  to  be  packed  tightly  into  the  alveolus  with  a  dental 
plugger.     In  packing  the  cotton  it  is  well  to  begin  at  one  end  and  crimp 

it  upon  itself  until  the  socket  is  entirely  filled. 
The  plug  in  a  few  cases  may  re(  pi  ire  retention 
in  position  by  compression.  This  is  accom- 
plished by  holding  a  few  folds  of  muslin  or 
similar  material  over  the  plug,  closing  the 
mouth  and  binding  the  jaws  together  with  a 
few  turns  of  a  Barton's  bandage  (Fig.  6(i3). 
The  25  per  cent,  ethereal  solution  of  hydrogen 
dioxid  in  small  quantity  on  cotton  packed 
into  a  bleeding  .socket  is  a  most  efficient  styptic,  and  will  effectually 
control  severe  hemorrhage  after  extraction.  Care  must  be  exercised 
not  to  use  the  solution  in  excess,  as  it  may  cause  injury  to  adjacent 
parts. 

When  hemorrhage  occiirs  from  the  surrounding  tissue,  as  in  patients 
in  an  anemic  condition  or  in  cases  of  hemorrhagic  diathesis,  the  case 
usually  falls  into  the  hands  of  a  general  practitioner  for  systemic  treat- 


Showing  compress  and  ligatures. 


ACCIDENTS  609 

ment,  but  the  local  treatment  usually  enij)loyed  by  physicians  in  these 
cases  is  often  unsatisfactory,  many  usint>;  Monsel's  solution  of  per- 
sulfate  of  iron,  which,  althou(>;h  it  may  be  a  good  styptic  for  use  in  other 
parts  of  the  body,  should  not  be  used  in  the  mouth.  The  local  treat- 
ment m  such  cases,  whether  soon  after  extracting  or  not,  is  first  to 
remove  all  clots  from  the  woimd  and  find  the  exact  place  or  places 
from  which  the  blood  is  exuding.  X  suitable  styptic  and  compression 
are  the  principal  means  used  for  stopping  it,  the  latter  perhaps  being 
the  most  important.  Tannic  acid  applied  on  cotton,  lint,  or  similar 
substances  is  an  excellent  styptic  for  this  use.  Compression  can  be 
applied  as  the  ingenuity  of  the  operator  may  direct.  When  a  hemor- 
rhage occurs  from  a  socket  between  sound  teeth,  it  can  be  readily  con- 
trolled by  two  ligatures,  making  one  fast  to  each  tooth,  then  placing  in 
position  and  tying  the  four  ends  together  over  the  compress,  as  shown 
in  Fig.  664.  In  a  few  rare  cases  an  impression  of  the  parts  should  be 
taken  in  wax  or  modelling  compound  in  order  that  a  vulcanite  or  metallic 
plate  can  be  made  to  hold  the  styptic  compress  in  position.  After  the 
compress  is  in  position  warmed  modelling  compound  can  be  placed 
over  it  and  the  jaws  brought  together  and  retained  in  place  by  a  head 
bandage.  A  plug  of  hardening  plaster  of  Paris  may  be  made  and 
forced  into  the  bleeding  socket  in  obstinate  cases,  or  in  exiremis  the 
extracted  tooth  might  be  soaked  well  in  phenol-sodique  and  reinserted. 
A  very  efficient  local  hemostatic  is  a  1  to  1000  solution  of  adrenalin 
chlorid.  A  piece  of  iodoform  gauze  moderately  soaked  in  this  solution 
and  packed  in  the  tooth  socket  will  often  control  severe  hemorrhage. 
This  drug  acts  bv  causing  constriction  of  the  bloodvessels.  It  is  the 
most  powerful  vasoconstrictor  known,  although  its  effects  do  not  last 
long. 

The  systemic  treatment  is  often  important;  if  the  patient  is  seen 
to  be  anemic  or  known  to  be  of  the  hemorrhagic  diathesis,  the  treat- 
ment should  be  begun  before  extracting.  This  is  done  by  thoroughly 
building  up  the  system  by  a  course  of  hygienic  and  tonic  treatment. 
The  cause  of  bleeding  in  cases  where  the  hemorrhagic  diathesis  exists 
is  but  imperfectly  understood;  the  blood  may  be  so  defibrinated  that  it 
has  lost  the  power  of  coagulation  and  so  will  not  form  a  clot,  or  the 
muscular  coats  of  the  vessels  have  lost  their  tonicity,  either  through 
general  debility  or  the  lack  of  energy  in  the  vasomotor  nervous  system, 
which  prevents  their  contracting  so  as  to  close  the  lumen.  Certainly 
the  walls  of  the  capillaries  permit  free  transudation  of  the  blood.  In 
good  health  the  proper  coagulation  and  the  contraction  of  the  blood- 
vessels will  stop  the  hemorrhage  even  when  an  artery  of  considerable 
size  is  lacerated,  especially  if  the  flow  be  held  in  abeyance  by  artificial 
means  for  a  short  time.  It  is  when  the  blood  will  not  coagulate  and 
the  vessels  fail  to  contract  that  a  thorough  systemic  treatment  must 
be  given.  This  lack  of  normal  function  on  the  part  of  the  blood  and 
39 


610  EXTRACTION  OF  TEETH 

vessels  may  arise  from  various  diseases,  and  in  order  to  treat  judiciously 
a  patient  exhibiting  the  hemorrhagic  diathesis,  a  thorough  examination 
must  be  made  and  such  treatment  given  as  the  diagnosis  indicates. 
Among  the  most  common  causes  of  hemorrhage  are  anemia,  syphilis, 
purpura,  tuberculosis,  and  a  generally  impaired  vitality,  rarely  an  over- 
acting heart;  the  passive  hyperemia  attendant  upon  a  weak  heart  is  a 
potent  factor  requiring  a  course  of  preliminary  treatment. 

Specific  and  special  diseases  must  of  course  receive  the  treatment 
peculiar  to  these  conditions.  On  general  principles  the  following  tonics 
are  advisable:  Quassia,  cinchona  and  its  alkaloids,  iron  in  its  various 
forms,  sulfuric  and  hydrochloric  acids,  arsenic,  phosphorus,  nux  vomica 
and  its  alkaloid  strychnin.  Of  general  or  constitutional  hemostatic 
remedies,  the  best  are  certain  salts  of  calcium,  such  as  the  chlorid  and 
the  lactate,  and  of  magnesium  such  as  the  carbonate.  They  act  l)y 
increasing  the  coagulability  of  the  blood.  It  must  be  remembered, 
however,  that  an  excess  of  calcium  salts  tends  to  reduce  the  coagulability 
of  the  blood,  so  that  prolonged  use  of  these  drugs  may  do  more  harm 
than  good.  A  combination  of  these  seems  to  be  more  effectual  than 
calcium  chlorid  alone.  Thirty  grains  of  calcium  chlorid  or  lactate 
with  thirty  grains  of  magnesium  carbonate  may  be  given  as  an  initial 
dose  followed  on  succeeding  days  by  fifteen  grains  of  each  drug  or  five- 
grain  tablets  of  extract  of  thymus  gland  may  be  given  up  to  twenty  a 
day  to  supply  the  nucleo-albumin  necessary  for  coagulation  of  the  l:)lood. 
Very  frequently  the  digestive  organs  require  special  medication,  when 
such  remedies  as  pepsin,  pancreatin,  hydrochloric  acid,  and  bismuth 
subnitrate  are  indicated. 

The  following  prescriptions  have  proved  to  be  very  excellent  in  their 
special  province. 

As  general  tonics: 

I^ — Sodii  arsenit gr.  j 

Ferri  sulphat.  exsiccat., 

Sodii  bicarb aa     5j 

Ft.  pilulse  No.  xx. 

Sig. — One  after  each  meal. 

^ — Strychninse  siilph gr.  j 

Acid,  hydrochlor.  dil 5ij. 

Infus.  gentian,  comp.         q.  s.  ad  oiij 

Sig. — Teaspoonful  in  water  after  each  meal. 

In  cases  of  undue  hemorrhage  after  extracting,  it  is  well  to  administer 
a  hemostatic,  while  at  the  same  time  styptics  and  pressure  are  being 
applied  locally. 

EXTRACTION  UNDER  THE  INFLUENCE  OF  GENERAL  ANESTHETICS 

While  it  is  undoubtedly  true  that  the  extraction  of  teeth  under  the 
influence  of  a  general  anesthetic  is  in  accordance  with  the  general  spirit 


USE  OF  GENERAL  ANESTHETICS  Oil 

of  the  age  which  seeks  to  spare  all  suffering  or  cause  the  infliction 
of  but  slight  pain,  yet  many  evils  attend  such  general  and  too  often 
indiscriminate  use.  "A  patient  under  the  effect  of  so  powerful  a  drug 
that  consciousness  is  destroyed  is  nearer  death  than  an  ordinary  human 
being,  since  the  primary  depressive  influence  upon  the  high  nervous 
centres  mav  speedily  pass  to  the  lower  vital  centres  in  the  medulla 
oblongata."' 

The  indiscriminate  use  of  general  anesthetics,  besides  their  possible 
danger  to  life  and  health,  has  an  accompanying  evil  in  the  demand 
for  the  extraction  of  teeth  which  are  salvable  and  useful,  but  which 
a  patient  insists  upon  having  removed  in  order  to  avoid  the  discom- 
fort attendant  upon  their  treatment  and  filling.  No  one  questions 
or  denies  the  enormous  benefit  of  general  anesthetics  in  dentistry, 
particularly  when  painful  operations  are  to  be  performed  upon  ner- 
vous women  and  children;  but  if  the  patient  be  willing  to  suffer  a  little 
pain  it  is  generally  better  to  extract  without  a  general  anesthetic,  as  in 
that  case  the  patient  can  assist  the  operator  by  keeping  the  head  in 
a  desired  position  with  the  mouth  and  lips  well  open,  and  in  various 
other  ways,  while  under  the  influence  of  an  anesthetic  the  muscles 
supporting  the  head,  jaws,  and  cheeks  are  so  relaxed  that  it  is  difficult 
to  keep  the  mouth  and  lips  well  open. 

If  the  operation  is  to  extract  a  difficult  tooth,  the  operator  is  limited 
to  the  time  when  the  patient  is  under  the  influence  of  an  anesthetic,  and 
in  the  case  of  nitrous  oxid  the  time  is  very  short;  but  without  an  anes- 
thetic there  is  not  this  limitation  as  to  time,  and  the  extraction  may  be 
done  with  that  care  and  deliberation  essential  to  a  proper  operation.  It 
is  an  important  rule  in  any  branch  of  surgery  that  the  time  required 
to  do  an  operation  must  be  sufficient  to  do  it  properly  and  without 
unnecessary  injury  to  the  adjoining  tissues. 

Examination  of  a  Patient  before  the  Administration  of  a  General  Anes- 
thetic.— The  physical  examination  should  be  made  in  such  a  way  that 
it  will  not  cause  alarm  to  the  patient.  The  result  of  this  examination 
governs  the  selection  of  the  anesthetic,  and  to  some  extent  shows  how 
far  the  patient  should  be  carried  under  its  influence.  It  has  been 
said  that  a  greater  amount  of  care  should  be  used  if  the  patient  has 
or  is  suspected  of  having  organic  or  functional  disease  of  either  the 
heart  or  the  lungs.  This  is  quite  true ;  but  at  the  same  time  the  greatest 
amount  of  care  should  be  observed  in  all  cases. 

The  question  often  arises  whether  anesthetics  should  be  used  at  all 
if  the  patient  has  either  organic  or  functional  disorder  of  the  heart. 
That  depends  to  a  large  degree  on  other  conditions  of  the  patient.  If 
the  shock  of  extraction  will  be  less  under  ether  or  nitrous  oxid,  then  by 
all  means  the  anesthetic  should  be  given  and  the  patient  carried  well 

^  H.  A.  Hare,  Park's  Text-book  of  Surgery,  vol.  ii. 


612  EXTRACTION  OF   TEETH 

under  its  influence,  so  that  there  will  be  neither  pain  nor  knowledfje  of 
the  o})eration.  Occasionally  patients  suffering  from  heart  disorders 
can  bear  a  certain  amount  of  pain  without  shock;  in  such  cases  it  is 
better,  if  the  operation  be  a  simple  one,  to  extract  while  in  the  normal 
condition. 

It  is  also  true  that  an  individual  may  show  on  examination  evidences 
of  considerable  organic  defect  of  the  heart  without  running  any  more 
risk  than  a  person  who  shows  no  such  signs.  For  exam])le,  a  loud 
systolic  murmur  may  be  heard  at  the  apex  of  the  heart,  a  sign  of  mitral 
regurgitation,  and  at  the  same  time  the  patient  will  be  in  the  best  of  health 
as  far  as  functional  activity  of  the  heart  is  concerned.  Therefore  the 
presence  of  a  cardiac  murmur  in  itself  is  no  contraindication  to  the  use 
of  an  anesthetic,  but  if  the  patient  shows  signs  of  poor  compensation, 
i.  e.,  marked  dyspnea,  cough,  edema  of  the  feet,  or  irregularity  of  cardiac 
action,  extreme  caution  should  be  employed. 

These  remarks  apply  to  anesthesia  for  the  shortest  dental  operation 
whatever  the  anesthetic.  In  longer  operations  such  as  extraction  of 
impacted  teeth,  when  the  anesthesia  must  be  complete  and  kept  up  for 
some  time,  thorough  examination  of  the  lungs  and  kidneys  should  also 
be  made.  Pulmonary  tuberculosis  and  chronic  bronchitis  are  contra- 
indications to  ether  anesthesia.  In  testing  the  function  of  the  kidneys, 
the  quantity  of  urine  excreted  in  twenty-four  hours  as  well  as  the  presence 
of  albumin  or  casts  should  be  noted.  Ether  is  a  powerful  irritant  to  the 
kidneys,  albumin  and  casts  appearing  in  the  urine  after  its  adminis- 
tration in  a  great  number  of  cases  in  which  they  were  previously  absent. 
This  action  of  ether  must  therefore  be  borne  in  mind  in  its  adminis- 
tration. 

Ether  is  a  much  safer  anesthetic  than  chloroform.  Statistics  from 
various  sources  show  the  death  rate  from  ether  to  be  about  1  in  16,000, 
and  from  chloroform  1  in  4000,  a  proportion  of  1  to  4. 

Chloroform,  therefore,  should  not  be  used  except  under  very  exceptional 
circumstances  and  never  for  the  short  operations  here  under  consideration. 
Many  writers  recommend  its  use  especially  in  children  rather  than 
ether,  but  there  is  no  evidence  to  show  that  it  is  more  suitable  for  them 
than  for  adults.  It  has  been  truly  said  by  one  of  our  leading  teachers, 
"There  is  no  use  in  a  dental  surgery  for  chloroform  except  to  dissolve 
gutta-percha." 

The  disagreeable  effects  of  anesthetics  can  to  a  great  extent  be  avoided 
by  proper  preparation  of  the  patient.  In  all  long  operations  the  patient 
should  take  a  laxative  in  the  evening,  followed  on  the  morning  of  oper- 
ation by  an  enema  of  soap  and  water.  The  patient  should  eat  no  break- 
fast on  the  day  of  operation,  which  is  therefore  best  performed  in  the 
morning. 

Before  the  operation  the  patient  should  be  asked  to  empty  the  bladder 
and  bowels  if  possible,  the  clothing  should  be  loosened  about  the  neck, 


USE  OF  GENERAL  ANESTHETICS 


613 


Fig.  065 


and  all  removable  artificial  dentures  should  be  taken  from  the  mouth, 
and  a  mouth  prop  placed  in  position. 

The  ordinary  dental  chair  is  not  well  suited  to  operating  under  general 
anesthetics.  In  nitrous  oxid  anesthesia,  the  body  assumes  a  position 
of  hyperextension  and  the  foot  rest  or  other  parts  of  the  dental  chair 
may  be  broken  by  the  force  of  the  muscular  contraction.  If  a  dental 
chair  must  be  used,  the 
foot-rest  should  be  lowered 
out  of  reach  of  the  patient's 
feet  before  giving  the  anes- 
thetic, and  a  detached  stool 
placed  beneath  the  feet. 
For  longer  operations,  the 
patient  should  be  placed 
in  a  recumbent  or  semi- 
recumbent  position. 

The  use  of  ether  for  ex- 
tracting has  certain  advan- 
tages. If  for  any  reason 
the  operation  requires 
longer  time  for  its  per- 
formance than  theinfiuence 
of  the  nitrous  oxid  will  last 
— say  from  one  to  two 
minutes — it  is  better  to 
use  ether.  Ether  can  be 
given  after  the  patient  has 
become  anesthetized  by 
nitrous  oxid  and  oxygen, 
and  he  may  be  kept  under 
its  influence  for  a  consider- 
able time;  in  this  way  the 
struggling  stage  of  ether 
may  be  avoided.  When 
the  teeth  are  to  be  ex- 
tracted at  the  patient's 
home  or  at  any  other  place 
outside  of  an  operating 
room,  ether  is  more  con- 
veniently carried  than  nitrous  oxid.  If  properly  used  and  the  patient 
has  perfect  confidence  in  the  operator,  ether  can  be  so  administered  that 
one,  two,  or  three  teeth  may  be  extracted  during  what  is  known  as  the 
first  stage  of  ether  anesthesia,  before  complete  unconsciousness  and  long 
before  the  struggling  stage  commences. 

The  best  way  to  accomplish  this  is  to  administer  the  ether  in  a  cone  made 


Nitrous  oxid  gasometer. 


C14 


EXTRACT lOX  OF   TEETH 


bv  a  napkin  or  towel,  with  the  small  end  slightly  opened  so  as  to  allow  the 
patient  to  inhale  a  snffieient  quantity  of  air;  it  also  permits  the  patient 
to  exhale  freely  and  with  a  less  suffocating  effect.  It  is  well  to  place  in 
the  cone  a  small  soft  sponge  that  has  been  well  washed  with  hot  water. 
After  the  cone  is  ready  the  patient  should  be  instructed  to  breathe 
several  long  and  full  inhalations;  this  clears  the  lungs  of  much  impure 


—  -  —Water  line 


To  gas  cylinder 


Sectional  view  of  gasometer. 


air  and  accustoms  the  patient  to  the  kind  of  breathing  required.  Then 
the  appliance  is  placed  at  a  short  distance  above  the  mouth  and  nose  so 
that  the  vapor  will  gravitate  to  them,  being  careful  to  allow  none  of  the 
ether  to  drop  from  the  cone  upon  the  face,  as  it  would  demoralize  the 
patient.  The  inhaler  is  to  be  advanced  toward  the  face  slowly  and 
gradually,  watching  the  effect  upon  the  patient;  if  there  is  a  tendency 


USE  OF  GENERAL  ANESTHETICS  G15 

to  cough,  tlie  advance  should  be  interrupted  until  this  has  passed.    After 
the  cone  has  closed  ti<;htly  over  the  mouth  and  nose,  it  is  a  good  plan 

FifJ.  667 


Nitrous  oxid  inhaler. 


to  ask  the  patient  to  hold  up  the  left  hand  as  long  as  possible;  this  will 
concentrate  his  thoughts  upon  the  act  and  away  from  the  operation. 
When  the  hand  begins  to  fall,  the  request  to  raise  the  hand  should  be 


616 


EXTRACTION  OF   TKKTII 


repeated;  it  will  soon  fall,  and  in  a  few  seconds  afterward,  one,  two,  or 
three  teeth  may  be  removed,  the  number  di')X'iidin^r  entin^ly  u]nm  their 
position  and  th(>  diHiculty  to  be  overcome  in  their  extraction."    As  soon  as 


Fio.   008 


Hood  inhaler. 


the  teeth  are  extracted  the  head  of  the  patient  should  be  raised  from  the 
head-rest  and  the  bcxiy  carried  forward,  and,  having  a  hand  cuspidor 
in  front,  the  patient  should  be  requested  to  eject  the  blood  from  the 
mouth;  this  direction  is  usually  complied  with.     The  patient  in  most 


USE  OF  GENERAL  ANESTHETICS 


017 


instances  recovers  in  a  few  moments,  and  with   no  disagreeable  after- 
ett'ects;  hut   if  the  ether  is  carried   heyond  the  struggling  stage  to  the 


Fic.   069 


Stand  for  compressed  gas  cylinder,  gas  bag,  tube,  and  inhaler. 


618 


EXTRACTION  OF  TEETH 


point  of  complete  suroic-al  narcosis  the  nauscatintj;  after-effects  are  very 
disagreeable  unless  the  patient  has  been  thoroughly  prepared  for  the 
occasion. 

Nitrous  oxid  is  the  anesthetic  most  commonly  administered  for  the 
extraction  of  teeth,  and  under  ordinary  circumstances  is  the  best.  Until 
lately  every  operator  was  his  own  maker  of  the  gas — this  was  a  great 
disadvantage — but  now  it  can  be  procured  in  a  liquefied  form  com- 
pressed in  cylinders.  There  are  many  different  appliances  used  for 
the  administering  of  this  gas  even  when  using  it  in  a  condensed  form. 
One  of  the  most  prominent  is  that  shown  in  Figs.  ()05  and  ()(>(),  in  which 
the  gas  is  drr^wn  into  a  reservoir  and  then  passes  through  a  flexible 
tube  to  the  mouth-piece  (Figs.  067  and  668). 


Fig.  670 


Portable  nitrous  oxid  apparatus. 


The  two  principal  mouth-pieces  are  Fig.  667,  which  should  have 
the  detachable  lip-shield  removed  so  that  the  tube  may  be  placed 
directly  into  the  mouth  and  the  lips  compressed  around  the  tube  by  the 
operator,  at  the  same  time  closing  the  nostril  by  the  thumb  and  finger, 
and  Fig.  668,  which  is  known  as  a  hood  inhaler;  it  is  made  to  cover 
the  nose  as  well  as  the  mouth.  The  advantage  of  the  first  mouth- 
piece is  that  the  lips  may  be  closely  watched  for  the  change  of  color 
denoting  oxygen  starvation  of  the  blood,  wiiich  the  experienced  oper- 
ator combats  by  admitting  a  certain  amount  of  air  with  the  gas  as 


USE  OF  GENERAL  ANESTHETICS  619 

required.  This  advantage  can  he  given  (o  the  hood  inlialer  shown  in 
Fig.  668  by  having  it  made  of  transparent  material,  such  as  celluloid. 
Fig.  670  represents  a  portable  appliance  to  be  used  at  a  patient's  home 
or  away  from  the  regular  office. 

Hewitt's  Method.— Sir  Frederic  Hewitt,  of  London,  England,  has 
devised  the  apparatus  shown  in  Figs.  671  and  672.  The  three  cylinders 
contain  the  compressed  gas,  two  being  filled  with  nitrous  oxid  and 
one  with  oxygen.  The  valves  of  the  cylinders  are  opened  by  a  key 
which  is  controlled  by  the  foot  of  the  operator.  The  tube  passing  from 
the  cylinders  to  the  receiving  bag  is  double,  a  smaller  tube  being  placed 
within  the  outer  larger  tube.  The  receiving  bag  is  also  double,  being 
divided  by  a  rubber  septum  into  two  compartments  which  have  their 
outlet  in  the  double  tube  which  leads  to  the  inhaler.  To  the  receiving 
bag  is  attached  a  mixing  chamber,  and  to  this  the  inhaling  tube  or  hood 
is  fastened.  This  appliance  is  used  very  successfully  in  England  and 
has  been  introduced  into  the  United  States.  It  has  proved  satisfactory 
to  all  who  have  tried  it.  The  bags  and  tubing  should  be  made  of  more 
durable  material  when  intended  for  use  in  the  American  climate. 

The  manner  in  which  the  appliance  is  used  is  as  follows :  The  valves 
in  the  mLxing-chamber  (Fig.  672)  are  closed,  then  oxygen  is  let  into  its 
compartment  of  the  receiving  bag  until  the  latter  is  nearly  filled,  when 
the  nitrous  oxid  is  admitted  into  its  compartment.  The  patient  being- 
prepared,  the  inhaling  tube  or  hood  is  placed  in  position,  and  the  patient 
is  directed  to  breathe — long,  full,  and  steadily.  If  the  tube  is  used  it 
is  necessary  to  close  the  nose  by  the  thumb  and  finger. 

The  valves  are  not  changed  for  a  few  inhalations,  during  which  time 
only  air  is  inhaled;  then,  pressing  the  indicator  a  downward  to  the  first 
notch  b,  the  air  is  cut  off,  and  the  patient  receives  pure  nitrous  oxid; 
this  is  allowed  for  a  few  more  inhalations,  and  then  the  indicator  is 
carried  to  the  next  notch  and  one  part  of  oxygen  is  allowed  to  pass  into 
the  respiration.  When  the  indicator  is  carried  to  the  third  notch  two 
parts  are  received  by  the  patient,  and  so  on  until  the  maximum  amount 
of  oxygen  required  by  the  patient  has  been  reached. 

It  has  been  found  by  careful  study  of  many  thousands  of  cases  and 
by  special  scientific  investigation  that  the  asphyxial  condition  incident 
to  most  cases  of  nitrous  oxid  inhalation  is  quite  unnecessary  to  the  pro- 
duction of  nitrous  oxid  anesthesia.  It  is  also  justly  considered  to  be 
subjecting  a  patient  to  an  unwarrantable  danger  to  permit  the  asphyxial 
effect  to  manifest  itself  to  a  profound  degree,  as  in  many  cases  it  is 
a  menace  to  life  and  health,  and  might  have  a  fatal  effect.  The  object 
of  Dr.  Hewitt's  method  is  to  control  or  eliminate  the  asphyxial  element 
by  administering  a  requisite  amount  of  oxygen. 

No  fixed  rule  can  be  laid  down  for  the  quantity  of  oxygen  to  be  added, 
as  each  case  will  require  a  different  amount,  and  this  amount  varies 
during  the  several  stages  of  the  anesthetic  procedure.     The  operator 


620 


EXTRACTION  OF  TEETH 

Yiv..   (171 


Complete  apparatus  of  Dr.  Hewitt  for  administering  mixed  nitrous  oxid  and  oxygen. 
Fig.  672 


Showing  arrangement  of  the  mixing  chamber,  with   dial' and   valve  for  controlling   the 
relative  proportions  of  the  gases. 


USE  OF  dENEHAL   ANESTHETICS 


621 


is  n;iii(l(>(l  entirely  by  the  syinptoins  of  the  patient  duriiif^r  the  adminis- 
tration, his  object  being  to  avoid  on  the  one  hand  the  tendency  toward 


Fig.  673 


Apparatus  for  administering  nitrous  oxid  and  oxygen  combined:  a,  key  to  oxygen  bag;  6,  key  to 
oxygen  cylinder;  c,  gauge  showing  percentage  of  oxygen  being  administered;  d,  mixing  chamber; 
e,  e,  keys  to  nitrous  oxid  cylinders;  /,  key  to  nitrous  oxid  bag. 


622  EXTRACriOX  OF   TEEril 

asplivxia  indicated  1)V  cyanosis  of  tlie  lips,  and  return  of  consciousness 
and  vensation  on  the  other  hand,  whicli  is  easily  produced  by  an  excess 
of  oxygen.  By  tlie  athnixture  of  oxygen,  as  in  Dr.  Hewitt's  method, 
the  anestliesia  is  somewhat  j)roh)nged  over  tlie  ordinary  nitrous  oxid 
method  and  is  slower  of  induction;  l)Ut  there  is  entire  absence  of  cyanosis, 
stertorous  breathing,  jactitation,  or  any  of  the  symptoms  of  asphyxia. 
The  modification  of  the  Hewitt  apparatus  that  has  been  lately  intro- 
duced embodies  certain  features  that  make  it  an  improvement  on  the 
original  apparatus.  Hie  arrangement  of  the  mixing-chamber  in  reference 
to  the  bags  containing  the  ga.ses  is  such  as  to  enable  the  operator  to  more 
accurately  control  the  mixture  that  is  administered  to  the  patient.  By 
a  turn  of  the  levers  a  and  /  ( Fig.  672)  any  gradation  of  the  gases  may 
be  obtained,  from  pure  nitrous  oxid  on  the  one  hand,  to  pure  oxygen  on 
the  other.  The  construction  of  the  apparatus  is  such  as  to  better  with- 
stand the  climatic  conditions  than  the  Hewitt  apparatus.  A  brief 
description  will  suffice  to  show  the  working  of  the  apparatus. 

There  are  three  cylinders,  two  containing  compressed  nitrous  oxid, 
and  the  other  compressed  oxygen. 

Two  bags,  one  of  black  material  to  contain  the  nitrous  oxid,  the 
other  of  red  material  to  contain  the  oxygen. 

The  key  to  each  cylinder  (see  h  and  e,  e)  opens  the  valve  and  allows 
the  gas  to  pass  into  its  respective  bag. 

By  opening  the  valve  (see  f)  of  the  nitrous  oxid  bag  the  gas  passes 
into  the  mixing  chamber,  from  which  it  flows  through  the  covered 
rubber  tube  to  the  inhaler. 

When  it  is  desired  to  combine  oxygen  with  nitrous  oxid,  open  gauged 
valve  (see  a,  c)  to  the  oxygen  bag;  this  will  admit  the  oxygen  into  the 
mixing  chamber.     Both  gases  will  pass  through  the  tube  to  the  inhaler. 

The  proportion  of  oxygen  used  will  be  determined  by  the  degree  to 
which  the  gauged  valve  is  opened. 

By  closing  the  valve  of  the  nitrous  oxid  bag,  oxygen  can  be  given 
separately. 

Similar  results  are  obtained  when  air  is  admitted,  instead  of  oxygen, 
to  the  patient  during  the  nitrous  oxid  administration. 


CHAPTER    XVIII 

LOCAL  ANESTHESIA 

By  HERMANN  PRINZ,  M.D.,  D.D.S. 

Local  anesthetics  are  agents  which  are  employed  for  the  purpose  of 
producing  insensibility  to  pain  in  a  circumscribed  area  of  tissue. 

History. — From  an  historical  viewpoint,  comparatively  few  important 
factors  are  to  be  recorded  prior  to  the  introduction  of  coca  in  for  the  pur- 
pose of  locally  obtunding  pain.  The  compression  of  nerve  trunks  for  the 
abolition  of  pain  seems  to  be  of  an  old  and  unknown  origin,  which  was 
revived  by  Guy  du  Chauliac  and  Ambroise  Pare,  and  indirectly  found 
a  permanent  place  in  surgery  as  the  Esmarch  elastic  bandage.  Physi- 
cally reducing  the  temperature  of  a  part  of  the  body  by  the  application 
of  cold  was  instituted  much  later.  Bartholin  and  Severino  introduced 
this  method  in  the  middle  of  the  Sixteenth  century.  It  became  a  lost  art, 
however,  until  John  Hunter,  of  London,  again  called  attention  to  its 
benefits  by  demonstrating  it  upon  animals,  and  Larrey,  the  chief  surgeon 
of  Napoleon's  army,  employed  it  for  amputating  purposes  (1807). 
Through  the  efforts  of  Sir  B.  W.  Richardson,  in  1866,  it  was  placed 
upon  a  rational  basis  by  the  introduction  of  the  ether  spray.  The  various 
narcotics  which  were  employed  for  internal  purposes  were  also  made 
use  of  as  local  applications.  INIandragora,  henbane,  aconite,  the  juice 
of  the  poppy-head,  and  many  other  analgesic  drugs  enjoyed  a  world- 
wide reputation.  The  empirical  search  for  new  methods  and  means 
pressed  the  mysticism  of  the  electric  current  into  service,  opening  a 
prolific  field  to  the  charlatan  which  even  to  this  day  has  not  lost  its 
charm.  Richardson's  voltaic  narcotism  for  a  time  attracted  the  atten- 
tion of  the  medical  profession;  and  Francis,  in  1858,  recommended  the 
attachment  of  the  electric  current  to  the  forceps  for  the  painless  extrac- 
tion of  the  teeth,  and  as  dental  depots  still  offer  appliances  of  this  nature 
for  sale,  it  seems  that  the  method  is  still  in  vogue  with  some  operators. 
In  the  early  days  of  modern  dentistry  we  meet  with  many  feeble  efforts 
to  alleviate  pain  during  trying  operations.  Chloroform,  alcohol,  ether, 
aconite,  opium,  the  essential  oils,  and  many  other  drugs  were  the  usual 
means  employed,  either  simply  or  as  compounds,  usually  under  fanciful 
names,  for  such  purposes.  Snape's  calorific  fluid,  composed  of  chloro- 
form, tincture  of  lemon  balm,  and  oil  of  cloves;  nabalus,  consisting  of 
glycerite  of  tannic  acid  and  a  small  quantity  of  chloral  hydrate;  INIorton's 
letheon,  which   was    sulphuric    ether   mixed    with    aromatic    oils,  are 

(623) 


624  LOCAL  ANESriJESIA 

examples  of  proprietary  pr('|)arati()iis  which  ciijoyod  (piitc  a  reputation 
in  their  time. 

In  1S53  Alexander  Wood  introduced  a  method  of  fjeneral  medication 
by  means  of  hypodermic  injections.  At  once  it  was  .snirjfested  to  emj)l()y 
such  drugs  as  morphin  or  tincture  of  o})ium  for  the  purjjose  of  pro- 
ducinnj  local  anesthesia.  The  results  were  not  encouraji;in<,',  however, 
until  Roller,  in  1S,S4,  advocated  cocain.  With  the  introdnction  of  this 
druo;  into  therajxnitics,  local  anesthesia  achieved  resuhs  which  were 
beyond  expectations,  and  its  adoption  created  a  new  era  in  local  anes- 
thesia. 

Means  of  Producing  Local  Anesthesia. — The  term  anesthesia  (without 
sensation),  which  was  suggested  in  184(3  by  that  great  physician- 
literateur,  Oliver  Wendell  Holmes,  to  Dr.  Morton,  is  usually  defined 
as  an  artificial  de})rivation  of  all  sensation,  while  the  mere  absence 
of  pain  is  referred  to  as  analgesia.  Correctly  speaking,  the  term  local 
anesthesia  is  partially  a  misnomer.  In  producing  local  anesthesia  we 
do  not  fully  comply  with  all  the  recjuirements  that  anesthesia  demands, 
because  a  part  of  the  sensorium — the  sense  of  touch,  for  instance — is  not 
abolished.  The  term  local  anesthesia  has,  however,  acfjuired  such 
universal  recognition  that  it  would  seem  unwise  to  recommend  a  change. 

Anesthesia  may  be  artificially  produced  by  inhibiting  the  sensory 
nerve  fibers  at  their  central  end-organs  in  the  brain  or  at  their  peripheral 
end-organs  in  the  tissues,  thus  producing  general  and  local  anesthesia. 
Local  anesthesia  may  be  obtained  in  two  definite  ways.  W^e  may 
inhibit  the  function  of  the  peripheral  nerves  in  a  circumscribed  area  of 
tissue,  and  we  refer  to  this  process  as  "terminal  anesthesia,"  while  if 
we  block  the  conductivity  of  a  sensory  nerve  trunk  somewhere  between 
the  brain  and  the  periphery  we  speak  of  it  as  "conductive  anesthesia." 
Conductive  anesthesia  may  be  produced  by  injecting  into  the  ner\'e 
trunk  proper — endoneural  injection — or  by  injecting  into  the  tissues 
surrounding  a  nerve  trunk — perineural  injection.  The  latter  form  is 
the  usual  method  pursued  when  conductive  anesthesia  for  dental  pur- 
poses is  indicated.  Specific  forms  of  local  anesthesia  may  also  be  pro- 
duced by  paralyzing  the  sensory  ganglia  in  the  brain  or  in  the  spinal 
cord;  these  methods  have,  however,  no  bearing  on  the  subject  under 
consideration. 

The  successful  practice  of  local  anesthesia  involves  (he  careful 
co5rdination  of  a  number  of  important  details,  each  one  constituting  a 
definite  factor  in  itself,  which,  when  neglected,  must  necessarily  result 
in  failure.  As  a  whole,  the  practice  of  local  anesthesia  by  the  hypo- 
dermic method  represents  a  composite  of  the  following  factors: 

1.  A  solution  of  active  ingredients  in  accord  with  the  physical  and 
physiological  laws  which  govern  certain  functions  of  the  living  cell. 

2.  A  carefully  selected  hypodermic  armamentarium. 

3.  A  complete  mastery  of  the  technique. 


pnyjsioLoaicAL  action  of  axesthetks  625 

4.  A  proper  selection  of  tlie  correct  method  suitable  for  the  case  at 
hand. 

5.  (jrood  judi^niieiit  of  prevailing  conditions. 

Physiological  Action  of  Anesthetics. — According  to  more  recent  thera- 
peutic conception,  it  is  generally  recognized  that  a  drug  or  a  combina- 
tion of  drugs  which  simultaneously  produce  local  anemia  and  inhibition 
of  the  sensory  nerves  in  a  circumscribed  area  of  tissue  is  the  logical 
solution  of  the  question  of  local  anesthesia.  Certain  important  factors, 
however,  relative  to  the  physiological  and  physical  action  of  the  solution 
employed  for  hypodermic  injection  upon  the  cell,  govern  the  successful 
application  of  such  methods.  It  is  of  prime  importance,  therefore,  to 
comply  with  the  laws  regulating  the  absorption  of  injected  solution,  viz., 
osmotic  pressure. 

If  we  separate  two  solutions  of  salt  of  different  concentration  by  a  per- 
meable membrane,  a  continuous  current  of  salt  and  water  through  the 
membrane  results,  which  ceases  only  after  equalization  of  the  density  of 
the  two  liquids,  viz.,  when  equal  osmotic  pressure — according  to  the 
Boyle-Van't  Hoff's  law — is  established.  The  current  passes  in  both 
directions,  drawing  salt  from  the  stronger  to  the  weaker  solution  and 
water,  vice  versa,  until  osmotic  equilibrium  is  obtained.  The  resultant 
solutions  are  termed  isotonic  (De  Vries).  Osmotic  pressure  is  a  physical 
phenomenon  which  is  possessed  by  water  and  all  aqueous  solutions;  it  is 
dependent  upon  the  number  of  molecules  of  salt  present  in  the  solution 
and  upon  their  power  of  dissociation.  In  organized  nature  these  osmotic 
interchanges  are  an  important  factor  in  regulating  the  tissue  fluids  of 
both  animals  and  plants.  In  the  animal  tissue  the  circulation  depends 
principally  upon  the  mechanical  force  exerted  by  the  heart.  The  life 
of  the  cell  depends  upon  the  continuous  passage  of  the  fluids  which 
furnish  the  nutrient  materials,  consisting  of  w^ater,  salt,  and  albumin. 
These  chemicals  are  normally  present  in  certain  definite  proportions. 
The  membrane  of  the  living  cell  is,  however,  only  semipermeable,  \\z., 
the  cell  readily  absorbs  distilled  water  when  surrounded  therewith;  it 
becomes  macerated,  loses  its  normal  structure,  and  finally  dies.  If,  on 
the  other  hand,  the  surrounding  fluid  be  a  highly  concentrated  salt 
solution,  the  solution  absorbs  water  from  the  cell ;  no  salt  molecules  enter 
the  cell  body  proper.  The  cell  shrinks  and  finally  dies.  This  process  of 
cell  death  is  in  general  pathology  referred  to  as  necrobiosis. 

A  further  important  factor  teaches  us  that  all  aqueous  solutions  which 
are  isotonic  possess  the  same  freezing  point,  viz.,  all  solutions  possessing 
an  equal  freezing  point  are  equimolecular;  they  possess  equal  osmotic 
pressure.  This  law  of  physical  chemistry  has  materially  simplified  the 
preparation  of  such  solutions.  The  freezing  point  of  human  blood, 
lymph  serum,  etc.,  has  been  found  to  equal,  approximately,  0.55°  C, 
which  in  turn  corresponds  to  a  0.9  per  cent,  sodium  chlorid  solution. 
Such  a  solution  is  termed  a  physiological  salt  solution.  In  the  older 
40 


620  LOCAL  ANESTHESIA 

works  on  pliysiolofxy  a  ().()  per  cent,  scxlium  chlorid  solution  is  referred 
to  as  a  physiolojfical  salt  solution;  this  solution  corresj>()n(ls  to  tlie 
density  of  the  blood  of  a  frog.  A  slight  deviation  above  and  below  the 
normal  percentage  of  the  solid  constituents  is  j)erniissible.  When 
physiological  salt  solution  at  body  teni]:)erature  is  injected  into  the  loose 
connective  tissue  under  the  skin  in  moderate  (piantities,  neither  swelling 
nor  shrinkage  of  the  cells  as  sucii  occurs;  a  simple  wheal  is  formed  which 
soon  disappears,  therefore  no  irritation  results,  and  in  conse(juence  no 
pain  is  felt.  ( )ther  similar  bodies  which  are  equally  soluble  in  water  act  in 
the  same  manner,  with  the  exception  of  the  salts  of  the  alkali  and  earth 
metals,  such  as  potassium  or  sodium  bromid,  for  example.  The  latter 
substances  produce  intense  physical  irritation,  followed,  however,  by 
prolonged  anesthesia,  and  in  consequence  are  termed  by  I.iebreich  "pain- 
ful anesthetics."  If,  on  the  other  hand,  simple  distilled  water  be  injected, 
a  superficial  anesthesia  only  is  produced;  the  injection  itself  is  very 
painful  and  acts  as  a  direct  protoplasm  poison  by  macerating  the  cell 
contents  and  resulting  in  severe  damage  or  even  death  of  the  cell.  If 
distilled  water  approximately  at  the  ratio  of  10  drams  to  the  pound  of 
body  weight  be  injected  into  dogs,  they  will  succumb  in  a  short  time. 
The  injection  of  higher  concentrated  salt  solution  produces  opposite 
effects;  water  is  removed  from  the  cells  with  more  or  less  pronounced 
pain,  also  followed  by  superficial  anesthesia.  The  red  corpuscles  are 
extremely  susceptible  to  any  injected  fluid  which  is  not  isotonic  in  its 
nature.  They  are  universally  destroyed  (hemolysis)  by  the  injection  of 
fluids  which  are  not  represented  by  an  isotonic  salt  solution.  Hypotonic 
solutions,  then,  cause  swelling  of  the  tissue,  while  hypertonic  solutions 
produce  shrinkage.  These  manifestations  are  proportionately  the  more 
intense  the  further  the  solution  is  removed  from  the  freezing  point  of 
the  blood.  Furthermore,  hypotonic  solutions  as  well  as  hypertonic 
solutions  require  much  more  time  for  their  absorption  than  isotonic 
solutions;  the  osmotic  pressure  has  to  be  standardized  to  the  surrounding 
fluid,  viz.,  to  the  isotonic  index  of  the  tissue  fluids.  Local  anemia  or 
ischemia,  viz.,  a  temporary  constriction  of  circulation — presents,  as  has 
been  experimentally  shown,  the  rapid  absorption  of  fluids  which  are 
injected  into  the  affected  area. 

The  more  important  means  to  produce  local  anemia  are:  (1)  The 
Esmarch  elastic  bandage.  (2)  The  application  of  cold.  (3)  The  extract 
of  the  suprarenal  capsule. 

Some  observers  have  maintained  that  local  anemia  produces  anes- 
thesia. This  is  not,  however,  the  case;  it  is  merely  an  important  means 
to  confine  the  injected  anesthetic  to  the  anemic  region,  and  thus  bring 
about  an  increased  and  prolonged  action  of  the  drug.  Consequently, 
the  concentration  of  the  anesthetic  solution  may  be  of  a  lower  percentage, 
which,  of  course,  lessens  the  danger  of  intoxication.  For  plausible  reasons 
the  Esmarch  elastic  bandage  cannot  be  made  of  use  for  dental  operations. 


ETHYL   CHLURID  ASD  ITS  ADMI MSTRATIOX  627 

Physically  ivdiiciiii;'  the  temperature  of  the  l)0(ly  by  the  application 
of  cold  (ice  pack,  ice  and  salt  luLxture,  cold  metals,  etc.)  was  practised 
by  the  older  suro^eons.  Arnott  in  1849  and  Blundell  in  1855  advocated 
ice  packs  for  the  painless  extraction  of  teeth.  Through  the  efforts  of  Sir 
B.  ^V.  Richardson,  in  1806,  this  method  was  placed  on  a  rational  basis 
by  the  introduction  of  his  ether  spray.  To  obtain  good  results,  a  pure 
ether  (boiling  point  95°  F.,  35°  C.)  free  from  water  is  necessary.  Certain 
volatile  hydrocarbons  possess  similar  properties  in  varying  degrees, 
depending  on  their  individual  boiling  point.  In  1867  Rottenstein  called 
attention  to  the  use  of  ethyl  chlorid  as  a  refrigerating  agent,  and  Rhein, 
in  1889,  introduced  methyl  chlorid  for  the  same  purpose.  In  1891 
Redard  reintroduced  ethyl  chlorid  as  a  local  anesthetic,  which  since  has 
become  known  by  many  trade  names — as  antidolorine,  kelene,  narcotile, 
etc. — and  mixtures  of  the  first  two  in  various  proportions  known  as 
anestol,  anestile,  coryl,  metethyl,  etc.,  are  extensively  used  in  minor, 
oral,  and  general  surgery.  A  pure  ethyl  chlorid  (boiling  point  55°  F., 
13°  C.)  is  best  suited  for  this  purpose,  as  it  lowers  the  temperature  of 
the  tissues  sufficiently  to  produce  a  short  superficial  anesthesia  in  a  few 
minutes.  Too  rapid  cooling  or  prolonged  freezing  by  methyl  chlorid 
(boiling  point,  12°  F.,  24.5°  C.)  or  the  various  mixtures  thereof,  produce 
deeper  anesthesia,  but  such  procedures  are  dangerous.  They  freqnentlv 
cut  off  circulation  in  the  affected  part  so  completely  as  to  produce 
sloughing  (gangrene).  Liquid  nitrous  oxid,  liquid  or  solid  carbonic 
acid  (recently  kno^^m  as  carbonic  acid  snow),  and  liquid  air.  all  of 
which  have  a  boiling  point  far  below  zero,  are  recommended  for  similar 
purposes,  but  they  require  cumbersome  apparatus  and  are  extremely 
dangerous. 

ETHYL  CHLORID  AND  ITS  ADMINISTRATION 

Ethyl  Chlorid  (^^lonochlorethane;  Hydrochloric  Ether;  C,!!.,^!). — "A 

haloid  derivative,  prepared  by  the  action  of  hydrochloric  acid  gas  on 


Ethyl  chlorid  spray  tube.      (Metal.) 


absolute  alcohol."    At  normal  temperature,  ethyl  chlorid  is  a  gas,  and 
under  a  pressure  of  two  atmospheres  it  condenses  to  a  colorless,  mobile. 


628  LOCAL  ANEiiTIIESIA 

very  volatile  liquid,  having  a  characteristic,  rather  agreeable  odor,  and 
burning  taste.  It  boils  at  about  55°  F.  (l.'3°  C.)  and  is  very  inflammable, 
burning  with  a  smoky,  green-edged  flame.  It  is  stored  in  sealed  glass 
or  metal  tubes,  and  when  liberated  at  ordinary  room  temperature, 
70°  F.  (21°  C),  it  evaporates  at  once.  In  commerce  it  is  supplied  in 
plain  or  graduated  glass  tubes  of  from  3  to  GO  grams'  capacity,  or  stored 
in  metallic  cylinders  holding  from  GO  to  100  grams  or  more.  To  remove 
the  ethyl  chlorid  from  the  hermetically  sealed  small  tubes,  the  neck  has 
to  be  broken  off,  while  the  larger  glass  and  metallic  tubes  are  provided 
with  suitable  stopcocks  of  various  designs  to  allow  definite  amounts  of 
the  li(|uid  to  be  released. 

Mode  of  Application. — For  the  extraction  of  teeth,  immediate  removal 
of  the  pulp,  opening  of  abscesses,  and  other  minor  operations  about  the 
oral  cavitv,  the  tube  should  be  warmed  to  body  temperature  by  placing 
it  in  heated  water,  and  its  capillary  end  should  be  held  about  six  to  ten 
inches  from  the  field  of  operation.  The  distance  depends  on  the  size 
of  the  orifice  of  the  nozzle,  and  complete  vaporization  should  always 
be  produced.  The  Gebauer  tube  is  fitted  with  a  spray  nozzle,  which 
shortens  the  distance  to  one  to  two  inches,  and  is  especially  well  adapted 
for  dental  purposes.  The  stream  is  directed  upon  the  tissues  until 
the  latter  are  covered  with  ice  crystals  and  have  turned  white.  For 
the  extraction  of  teeth,  the  liquid  should  be  projected  directly  upon  the 
surface  of  the  gum,  as  near  to  the  apex  of  the  root  as  possible,  but  care 
should  be  taken  to  protect  the  crown  of  the  tooth  on  account  of  the 
painful  action  of  cold  on  this  part.  The  tissues  to  be  anesthetized  should 
first  be  dried  and  well  surrounded  by  a  film  of  vaselin  or  glycerin,  and 
protected  by  cotton  rolls  and  napkins,  to  prevent  the  liquid  from  running 
into  the  throat.  Let  the  patient  breathe  through  the  nose.  (Jccasionally 
light  forms  of  general  anesthesia  are  induced  by  inhaling  the  vapor. 
On  account  of  the  difficulty  of  directing  the  stream  of  ethyl  chlorid  upon 
the  tissue  in  the  posterior  part  of  the  mouth,  it  is  not  successfully  applied 
to  those  regions.  The  intense  pain  produced  by  the  extreme  cold  pro- 
hibits its  use  in  pulpitis  and  acute  pericementitis.  To  anesthetize  the 
second  and  third  branch  of  the  fifth  nerve,  it  is  recommended  to  direct 
the  stream  of  ethyl  chlorid  upon  the  cheek  in  front  of  the  tragus  of  the 
ear,  but  the  author  has  not  seen  any  good  results  from  such  a  procedure. 
Caution  should  be  exercised  in  using  ethyl  chlorid  near  an  open  flame 
or  in  conjunction  with  the  thermocautery,  as  severe  burns  have  resulted 
by  setting  the  inflammable  vapor  on  fire. 

THE   ACTIVE    PRINCIPLE    OF   THE    SUPRARENAL   CAPSULE  AND 
ITS    SYNTHETIC    SUBSTITUTES 

Within  the  last  decade  the  active  principle  of  the  suprarenal  capsule 
has  evoked  extensive  comments  in  therapeutic  literature.     It  has  been 


SUPRAREXAL  CAPSULE  AXD  ITSSYNTHETIC  SUBSTITUTES      629 

isolated  by  a  numlier  of  investio;ators  uiuler  difi'erent  names,  as  epine- 
phrin  by  Abel  (1S07),  suprarenin  by  Fuerth  (189S),  and  adrenalin  by 
Takamine  and  Aldrich  (1901).  Many  other  titles  are  given  to  this 
chemical — as  adnephrin,  adrin,  paranephrin,  suprarenalin,  snpra- 
capsulin,  hemostasin,  etc.  The  United  States  Pharmacopoeia  (eighth 
revision)  has  not  as  yet  admitted  this  alkaloid  to  its  pages,  and,  therefore, 
whenever  we  refer  here  to  the  hydrochloric  salt  of  the  alkaloid  of  the 
snprarenal  capsule,  we  speak  of  it  as  adrenalin,  the  term  which  is  at 
present  preferred  in  the  United  States.  Adrenalin  is  a  grayish-white 
powder,  slightly  alkaline  in  reaction,  and  perfectly  stable  in  dry  form. 
It  is  sparingly  soluble  in  cold  and  more  soluble  in  hot  water,  is  insoluble 
in  ether  or  alcohol,  and  with  acids  it  readily  forms  soluble  salts.  The 
preparation  that  is  employed  mostly  for  therapeutic  purposes  is  a  solu- 
tion of  adrenalin  hydrochlorid  in  a  1  to  1000  physiologic  salt  solution, 
to  which  preservatives — as  small  quantities  of  chloretone,  thymol,  etc. — 
are  added.  Adrenalin  solution  does  not  keep  well.  On  exposure  to  air 
it  is  easily  oxidized,  becoming  pink,  then  red,  and  finally  brown,  and 
with  this  change  of  color  its  physiologic  property  is  destroyed.  If  the 
adrenalin  solution  be  further  diluted,  it  becomes  practically  worthless 
within  a  few  days. 

When  adrenalin  is  injected  into  the  tissues,  even  in  extremely  small 
doses,  it  temporarily  raises  the  arterial  blood  pressure,  acting  as  a 
powerful  vasoconstrictor  by  stimulating  the  smooth  muscular  coat  of 
the  bloodvessels,  and  thus  produces  local  anemia.  Large  doses  finally 
reduce  the  blood  pressure,  and  heart  failure  results.  The  respiration 
at  first  quickly  increases,  but  slows  down  and  finally  stops  with  expira- 
tion. Its  action  is  largely  confined  to  the  smooth  muscle  fibers  of  the 
peripheral  vessels.  Adrenalin  is  destroyed  by  the  living  tissue  cells, 
the  body  ridding  itself  of  the  poison  in  some  unknown  manner.  AYhile 
adrenalin  does  not  possess  local  anesthetic  action,  it  increases  very 
markedly  the  eflFect  of  certain  anesthetics  when  combined  with  them. 
These  observations  are  of  vast  importance  in  connection  with  the 
production  of  local  anesthesia.  Carpenter,  Peters,  Moller,  and  others 
referred  to  the  use  of  adrenalin  in  this  respect,  and  finally  Braun,  in  1902, 
published  his  classic  researches,  and  to  him  and  his  co-workers,  especially 
Heinze  and  Laewen,  belongs  the  credit  of  establishing  a  rational  basis 
for  the  production  of  local  anesthesia.  It  is  claimed  that  secondary 
hemorrhage  frequently  occurs  after  the  anemia  produced  by  the  adrenalin 
has  subsided,  and  that  the  tissues  themselves  suflPer  from  the  poisoning 
effect  of  the  drugs,  resulting  in  gangrene.  Such  results  are  produced 
only  by  the  injection  of  too  large  quantities  of  the  drug,  which  by  their 
deeper  action  close  up  the  larger  arteries.  The  prolonged  anemia  will 
give  way  to  a  dilatation  of  the  bloodvessels,  and,  if  the  tissues  are  too 
long  deprived  of  the  circulation,  we  are  able  to  understand  why  sloughing 
may  result.    Small  doses  of  adrenalin  have  no  eflFect  upon  the  tissues  or 


630  LOCAL  ANESTHESIA 

on  the  healing  of  a  wound.  Palpitation  of  the  heart  and  muscular 
tremor,  which  were  occasionally  noticed  in  the  early  period  of  the  use 
of  the  drug,  are  the  direct  result  of  too  large  doses.  Recently  a  synthetic 
adrenalin  has  been  successfully  prepared  by  Stolz,  which,  with  hydro- 
chloric acid,  forms  a  stable  and  readily  soluble  salt.  It  is  known  as 
synthetic  suprarenin  hydrochlorid.  The  new  chemical  has  been  care- 
fully tested  physiologically  and  in  clinical  work,  and  the  general  consensus 
of  opinion  points  to  the  fact  that  it  is  not  alone  equal,  but  in  certain 
respects  superior,  to  the  organo-preparations.  Synthetic  suprarenin 
solutions  may  be  readily  sterilized  by  boiling.  They  are  relatively 
stable,  and  their  chemical  purity  insures  uniform  results.  They  are  com- 
paratively free  from  dangerous  side  actions.  The  writer's  observations 
regarding  the  value  of  synthetic  suprarenin  relative  to  its  actions  and 
its  2"eneral  behavior  is  in  full  accordance  with  the  above  statements, 
and  its  advantages  over  the  organo-preparations  has  led  him  to  adopt  it 
as  a  component  in  the  preparation  of  local  anesthetic  solutions.  For 
dental  purposes — that  is  for  injecting  into  the  gum  tissue — the  dose  may 
be  limited  to  one  drop  of  the  adrenalin  solution  (1  to  1000)  or  the  syn- 
thetic suprarenin  solution  (1  to  1000),  added  to  each  cubic  centimeter 
of  the  anesthetic  solution,  5  drops  being  approximately  the  maximum 
dose  to  be  injected  at  one  time. 


THE  LOCAL  ANESTHETICS 

Cocain. — Cocain,  when  injected  into  the  tissues,  produces  typical 
local  and  general  effects.  Locally,  it  possesses  a  definite  affinity  for  the 
peripheral  nerves;  it  causes  constriction  of  the  smaller  arteries,  producing 
lio-ht  anemia  in  the  injected  area  with  diminished  action  of  the  leukocytes. 
However,  different  parts  of  the  organism  require  different  doses  to  bring 
about  the  same  reaction.  Upon  mucous  surfaces,  paralysis  of  the  sensory 
nerves  is  produced;  the  senses  of  touch  and  smell  are  temporarily  in- 
hibited. The  blood  as  such  and  the  circulation  suffer  little.  If  cocain 
in  Sufficient  quantities  is  absorbed  by  the  circulation,  general  manifesta- 
tions are  produced  from  bringing  other  tissues  in  close  contact  with  the 
poison.  The  principal  disturbances  of  the  central  nervous  system  make 
themselves  known  by  vertigo,  a  very  soft  pulse,  enlarged  and  staring 
pupils,  and  difficult  respiration.  Vomiting  may  occur;  the  throat  feels 
dry.  Intense  excitement  is  followed  by  epileptiform  spasms;  finally, 
complete  loss  of  sensation  and  mobility  results,  which  terminates  in 
death  from  cessation  of  respiration.  The  general  character  of  the  dis- 
turbances is  closely  related  to  that  which  occurs  in  chloroform  or  ether 
poisoning.  The  typical  picture  of  cocain  poisoning  is  produced  when 
the  blood  flowing  through  the  central  nersous  system  contains  a  suffi- 
cient c^uantity  of  the  drug,  even  for  a  moment  only,  which  is  dangerous 


THE  LOCAL  ANESTHETICS  631 

to  this  or^an.  No  maximum  dose  can  be  positively  established.  This 
is  equally  true  of  chloroform  and  ether  when  used  for  general  anesthetic 
purposes.  The  many  cases  of  so-called  idiosyncrasy  probably  find  an 
explanation  in  the  too  large  doses  which  formerly  were  so  frequently 
administered. 

With  our  increased  knowledge  of  the  action  of  cocain  upon  the  tissues 
and  a  proper  techni(jue  of  the  injection,  dangerous  results  are  com- 
paratively rare  at  present.  No  direct  antidotes  are  known;  the  treatment 
of  general  intoxication  is  purely  symptomatic.  Anemia  of  the  brain, 
which  is  of  little  consequence,  may  be  readily  overcome  by  placing  the 
patient  in  a  recumbent  position  or  by  complete  inversion,  if  necessary. 
As  a  powerful  dilator  of  the  peripheral  vessels  the  vapors  of  amyl  nitrite 
are  exceedingly  useful;  it  is  best  administered  by  placing  3  to  5  drops  of 
the  fluid  upon  a  napkin  and  holding  it  before  the  nostrils  for  inhalation. 
Flushing  of  the  face  and  an  increase  in  the  frequency  of  the  pulse  follows 
almost  momentarily.  For  convenience  sake,  amyl  nitrite  may  be  pro- 
cured in  small  glass  capsules,  holding  the  necessary  quantity  for  one 
inhalation.  Nausea  may  be  remedied  by  administering  small  doses  of 
spirit  of  peppermint,  aromatic  spirit  of  ammonia,  or  validol.  The  latter 
is  a  compound  of  menthol  and  valerianic  acid  and  deserves  special 
recommendation.  To  overcome  the  disturbances  of  respiration,  quickly 
instituted  artificial  respiration  is  the  alpha  and  omega  of  all  methods  of 
resuscitation;  the  only  drug  that  has  proved  to  be  of  value  in  this 
connection  is  strychnin  in  the  form  of  the  sulfate  or  the  nitrate,  in  full 
doses  by  means  of  hypodermic  injections. 

The  relative  toxicity  of  a  given  quantity  of  cocain  solution  depends 
upon  the  concentration  of  the  solution.  Reclus  and  others  have  clearly 
demonstrated  that  a  fixed  quantity  of  cocain  in  a  5  per  cent,  solution 
is  almost  equally  as  poisonous  as  five  times  the  same  quantity  in  a  ^ 
per  cent,  solution.  From  the  extensive  literature  on  the  subject  we  are 
safe  in  fixing  the  strength  of  the  solution  for  dental  purposes  at  1  per 
cent.  This  quantity  of  cocain  raises  the  freezing  point  of  distiMed 
water  just  a  little  above  0.1°  C.  To  obtain  an  isotonic  solution  corre- 
sponding to  the  freezing  point  of  the  blood,  0.8  per  cent,  of  sodium 
chlorid  must  be  added.  Having  thus  prepared  a  cocain  solution 
which  is  equal  to  the  blood  in  its  osmotic  pressure  upon  the  cell  wall, 
it  is  now  necessary  to  aid  the  slightly  vasoconstrictor  power  of  the  drug 
by  the  addition  of  a  moderate  quantity  of  adrenalin,  thus  increasing  the 
confinement  of  the  solution  to  the  injected  area  by  producing  a  deeper 
anemia,  for  the  twofold  purpose — (1)  to  act  as  a  means  of  increasing 
the  anesthetic  effect  of  cocain,  and  (2)  to  lessen  its  toxicity  upon  the 
general  system  by  slower  absorption.  As  stated  above,  1  drop  of  adrena- 
lin solution  added  to  1  c.c.  of  the  isotonic  cocain  solution  is  sufficient 
to  produce  the  desired  effect. 


632  LOCAL  ANESTHESIA 

A  suitiihle  .solution  for  dental  purposes  may  he  prepared  as  follows: 

I^— Cocain  hydrochlorid 5  grains  (0.30  gm.) 

Sodium  chloride 4  grains  (0.2.5  gm.) 

Sterile  water 1  fluidounce  (30.00  e.c.) 

To  each  syringeful  (2  c.c.)  add  two  drops  of  adrenalin  chlorid  solution  when 
used. 

Ready  made  cocain  solutions  can  only  he  sterilized  with  diffieulty; 
they  will  not  keep  when  fre(|uently  expo.sed  to  the  air.  Ready  made 
anesthetic  solutions  as  found  in  the  market  usually  contain  preser- 
vatives such  as  phenol,  naphthol,  boric  acid,  iodin,  essential  oils,  alcohol, 
etc.,  in  variable  cjuantities.  Some  of  these  solutions  have  a  distinct  acid 
reaction.  While  they  may  produce  a  serviceable  degree  of  anesthesia, 
they  usually  damage  the  injected  tissues  sufficiently  to  retard  the  normal 
process  of  wound  healing. 

Substitutes  for  Cocain. — Ever  since  the  introduction  of  cocain 
into  the  materia  medica  for  the  purpose  of  producing  local  anes- 
thesia, quite  a  number  of  substitutes  have  been  placed  before  the  pro- 
fession, for  which  superiority  in  one  respect  or  another  is  claimed 
over  the  original  cocain.  The  more  prominent  members  of  this  group 
are  tropacocain,  the  eucains,  acoin,  nirvanin,  alypin,  stovain,  novo- 
cain, and,  very  recently,  quinin  and  urea  hydrochlorid.  None  of 
these  compounds,  with  the  exception  of  novocain,  has  proved  satis- 
factory for  the  purpose  in  view.  The  classical  researches  of  Braun 
have  established  certain  factors  which  are  essential  to  the  value  of  a 
local  anesthetic.  These  factors  concern  their  relationship  to  the  tissues 
in  regard  to  their  toxicity,  irritation,  solubility  and  penetration,  and 
to  the  toleration  of  adrenalin. 

There  is  no  need  to  enter  here  into  a  discussion  of  the  pharma- 
cological action  of  the  drugs  usually  classified  as  local  anesthetics.  Let 
it  suffice  to  state  how  the  above-mentioned  drugs  fulfil  the  demands 
of  Braun.  Tropacocain  is  less  poi.sonous,  but  also  less  active  than 
cocain,  and  completely  destroys  the  action  of  adrenalin;  the  eucains 
partially  destroy  the  adrenalin  action,  and  are,  comparatively  speaking, 
equally  as  poi.sonous  as  cocain;  acoin  is  irritating  to  the  tissues  and  more 
poisonous  than  cocain;  nirvanin  pos.se.sses  litUe  anesthetic  value;  alypin 
and  stovain  are  clo.sely  related,  producing  severe  pain  when  injected, 
which  occasionally  has  resulted  in  gangrene. 

According  to  Le  Brocq,  the  toxicity  of  these  chemicals  may  be  ex- 
pressed as  follows. 

If  the  toxicity  of  cocain  is  taken  as  the  standard  and  expre.s.sed  as  1, 
then  that  of  alypin  will  represent  1.25;  nirvanin,  0.714;  stovain,  0.025; 
tropacocain,  0.5;  novocain,  0.49;  eucain  B,  0.414. 

Novocain  alone  fully  corresponds  to  every  one  of  the  above  claims. 
Its  toxicity  \b  about  two  to  six  times  less  than  cocain ;  it  does  not  irritate 
in  the  slightest  degree  when  injected,  consequently  no  pain  is  felt  from 


TIIK  LOCAL  ANESTHETICS  C33 

its  injection  per  sc;  it  is  soluble  in  its  own  weij^ht  of  water;  it  will  combine 
with  adrenalin  in  any  proportion  without  interfering  with  the  physio- 
logical action  of  the  latter,  and  it  will  be  readily  absorber!  by  the  mucous 
membrane.  The  studies  of  Biberfield  and  Braun  brought  to  light 
another  extremely  interesting  factor  concerning  the  novocain-adrenalin 
combination.  Both  experimenters,  working  independently  of  each 
other,  observed  that  the  adrenalin  anemia  on  the  one  hand,  and  the 
novocain  anesthesia  on  the  other  hand  were  markedly  increased  in  their 
total  effects  upon  the  tissues.  Consequently,  a  smaller  quantity  of  this 
most  happy  combination  is  required  to  produce  the  same  therapeutic 
effect  as  a  larger  dose  of  each  individual  drug  alone  would  produce 
when  injected  separately.  The  injection  of  a  solution  of  the  combined 
drugs  is  precisely  confined  to  the  injected  area;  general  effects  are  there- 
fore rarely  produced. 

Novocain. — Novocain  is  the  hydrochloric  salt  of  a  synthetically 
prepared  alkaloid,  the  methyl  ester  of  p-aminobenzoic  acid.  It  is  a 
white  crystalline  powder,  or  colorless  needle-shaped  crystals,  melting 
at  263°  F.  (156°  C).  It  may  be  heated  to  200°  F.  (120°  C.)  without 
decomposition.  It  dissolves  in  an  equal  amount  of  cold  water,  the 
solution  having  a  neutral  character;  in  cold  alcohol  it  dissolves  in  the 
proportion  of  1  to  30.  Caustic  alkalies  and  alkaline  carbonates  pre- 
cipitate the  free  base  from  the  aqueous  solution  in  the  form  of  a  colorless 
oil,  which  soon  solidifies.  It  is  incompatible  with  the  alkalies  and 
alkaline  carbonates,  with  picric  acid  and  the  iodids.  Its  solutions  may 
be  sterilized  by  boiling  without  decomposition. 

As  stated  above,  the  relative  toxicity  of  a  given  quantity  of  cocain 
in  solution  depends  upon  its  concentration;  this  same  peculiarity  is  not 
shared  by  novocain.  The  dose  of  novocain  may  be  safely  fixed  at 
one-third  of  a  grain  for  a  single  injection.  For  dental  purposes  a  1^ 
or  a  2  per  cent,  solution  in  combination  with  adrenalin  has  been  injected 
without  any  ill  results.  For  the  purpose  of  confining  the  injected  novo- 
cain to  a  given  area,  the  addition  of  adrenalin  in  small  doses,  on  account 
of  its  powerful  vasoconstrictor  action  is  well  adapted.  It  is  the  important 
factor  which  prevents  the  ready  absorption  of  both  drugs,  and  conse- 
quently largely  nullifies  poisonous  results.  An  injection  of  10  drops 
of  a  2  per  cent,  solution  of  novocain  labially  into  the  tissue  produces 
a  diffuse  anesthesia  lasting  approximately  twenty  minutes;  the  same 
quantity,  with  the  addition  of  one  drop  of  adrenalin  chlorid  solution, 
increases  the  anesthetic  period  to  over  one  hour,  and  localizes  the 
effect  upon  the  injected  area. 

A  suitable  solution  of  novocain  for  dental  purposes  may  be  prepared 
as  follow^s: 

I^~Novocain 10  grains           (0.60  gm.) 

Sodium  chlorid          4  grains           (0.25  gm.) 

Distilled  water 1  fluidounce  (30.00  c.c.) 

Boil. 


634 


LOCAL  AX EST H ESI  A 


To  each  syrinjijeful  (2  c.c.)  add  2  drops  of  adrenalin  chlorid  .solution 
when  used.  Fischer  stronfjly  advocates  the  followint,'  so-called  "normal 
anesthetic  solution,"  which,  when  prepared  under  strict  aseptic  pre- 
cautions, and  when  preserved  in  amber  colored  bottles,  will  keep. 

I^— Novocain 2.3  grains        (1.50  gm.) 

Sodium  chlorid 14  grains        (0.92  gm.) 

Thymol i  grain  (0.02  gm.) 

Distilled  water     ....     3  fluidounces,  IJ  fluidrams  (100  c.c.) 

Boil. 

To  each  c.c.  add  one  drop  of  synthetic  suprarcnin  solution  when  used. 

A  sterile  solution  may  be  made  extemporaneously  by  dissolving  the 
necessary  amount  of  novocain-ad renal  in  in  tablet  form  in  a  given 
quantity  of  boiled  distilled  water.  A  suitable  tablet  may  be  prepared  as 
follows: 

Py-Novocain i     grain  (0.022000  gm.) 

Suprarenin  hvdrochlorid t'^Vc  grain  (0.0000.54  gm.) 

Sodium  chlorid i     grain  (O.OOSOOO  gm.) 

One  tablet  dissolved  in  20  minims  of  sterile  water  mekes  a  2  i)er  cent,  solution  of 
novocain  ready  for  immediate  use. 


Fig.  675 


Dropping  bottle. 


Solutions  for  hypodermic  purposes  .should 
preferably  be  made  fresh  when  needed.  A 
small  glass  dish  and  a  dropping  bottle  constitute 
the  simple  outfit  for  such  work.  The  dropping 
bottle  should  hold  from  1  to  2  ounces.  A  suit- 
able one  is  made  by  the  ^^^litall-Tatum  Co., 
of  Philadelphia,  and  may  be  bought  in  the  drug 
shops.  It  should  be  provided  with  a  dust  cap. 
"A  groove  on  one  side  of  the  neck  of  the  bottle, 
and  a  vent  on  the  other  connected  with  two 
grooves  in  the  back  of  the  stopper  allow  the 
contents  to  flow  out  drop  by  drop.  A  quarter 
turn  of  the  stopper  closes  the  bottle  tightly." 
The  water  used  for  making  the  solution  .should 
be  boiled  and  filtered  distilled  water.  The  hypo- 
dermic solution  can  be  made  extemporaneously 
in  a  few  seconds:  Place  a  tablet  in  a  sterile 
glass  di.sh,  add  20  minims  ( 1  c.c.)  of  water,  and 
to  facilitate  the  solution,  ma.sh  the  tablet.  The 
solution  is  now  ready  for  immediate  use. 


THE  HYPODERMIC   ARMAMENTARIUM 

A  hypodermic  .syringe  that  answers  all  dental  purposes  equally  well 
is  an  important  factor  in  carrying  out  the  correct  techni{|ue  of  the 
injection.  The  injection  into  the  den.se  gum  tissue  requires  from  15 
to  50,  or  even  more,  pounds  of  pressure  as  registered  by  an  interposed 


THE  HYI'ODEHMIC  ARM AMENT Alii (.' M 


635 


dynamometer,   while  in  pressure  anesthesia   100  or  more   pounds  are 
frequently  applied. 

The  selection  of  a  suitable  hypodermic  syringe  is  largely  a  matter 
of  choice.    All-glass  syringes,^  glass-barrel  syringes,  and  all-metal  syringes 
are  the  usual    types   found   in 
the  depots.  Fig.  676 

After  testing  most  of  the 
dental  hypodermic  syringes 
offered  in  the  dental  depots 
within  the  last  five  years  by 
means  of  the  pressure  gauge  and 
in  clinical  work,  subjecting  the 
syringes  to  a  routine  wear  and 
tear,  the  author  has  found  that 
the  all-metal  syringes  of  the 
"Imperial"  type  are  to  be  pre- 
ferred over  other  makes.  They 
are  usually  made  of  nickel- 
plated  brass,  which,  however, 
is  a  disadvantage,  as  the  nickel 
readily  wears  off  from  the  piston, 
and  exposes  the  easily  corroded 
brass.  The  Manhattan  all-metal 
platinoid  syringe  gives  the  best 
general  service,  and  can  be  con- 
scientiously recommended.  The 
syringe  holds  40  minims  (2  c.c.) 
is  provided  with  a  strong  finger 
cross-bar,  and  is  extremely 
simple  in  construction.  The 
piston  consists  of  a  plain  metal 
rod,  without  a  thickened  or 
ground  piston-end  or  packing. 
The  piston-rod  is  sufficiently 
long  to  allow  about  2  inches  of 
space  between  the  cross-bar  and 
the  piston-top.  This  space  is  of 
importance,  as  it  allows  the  last 
drop  of  the  fluid  to  be  expelled 
under  heavy   pressure    without 

tiring  the  fingers.     The  packing  consists  of  leather  washers  inserted 
at  the  screw  point,  and  are  quickly  removed  and  replaced  if  necessary.^ 

1  An  all-glass  syringe  that  answers  every  demand  regarding  asepsis,  diirability, 
and  perfect  construction,  is  made  by  Burroughs,  Wellcome  &  Co. 

-  An  all-metal  syringe  has  been  introduced  by  Parke,  Davis  &  Co.,  which  is  provided 
with  the  "  Schimmel"  aseptic  needles  and  a  right-angle  attachment  for  the  latter. 


^^.^ 


Metal  syringe. 


636  LOCAL  ANESTHESIA 

The  livpodermic  .syrinf,fc  rcciuircs  can'fiil  attention.  It  is  not  nooossary 
to  sterilize  it  by  boilintj;  after  eaeli  u.se,  unless  it  should  be  contuniinuted 
with  blood  or  pus.  The  simple  repeated  washings  with  alcohol  and 
careful  dryinti;  is  sufficient.  The  cap  is  readjusted,  and  the  piston  rod 
is  covered  with  a  thin  film  of  carbolated  vaselin  or  surolcal  lubricating 
jelly  and  placed  in  position.  If  the  syringe  is  boiled,  all  the  washers 
must  be  removed.  The  syringe  is  best  kept  in  a  covered  ghiss  or 
metal  case;  a  large  bacteriological  Petri  dish  is  suitable  for  this  purpose. 
Leather-lined  or  felt-lined  boxes  afford  breeding  places  for  bacteria, 
and  should  not  be  used.  Some  operators  j)refer  to  keep  their  syringes 
constantly  in  an  antiseptic  solution  when  not  in  use,  and  others  prefer 
to  place  them  in  a  special  sterilizing  bottle,  which  bottles  may  now  be 
purchased  at  dental  depots. 

Dental  hypodermic  needles  should  be  made  preferably  of  seamless 
steel,  or,  still  better,  of  nickel-steel,  26  to  28  B.  &  S.  gauge,  and  provided 
with  a  short  razor  edge  point.  Thicker  needles  cause  unnecessary  pain, 
and  thinner  needles  are  liable  to  break.  Iridioplatinum  needles  are 
preferred  by  some  operators,  as  they  may  be  readily  sterilized  in  an 
open  flame.  The  needle  should  measure  from  a  quarter  to  a  half-inch. 
For  infiltration  anesthesia  one  inch  needles  are  necessary,  and  curved 
needles  of  various  shapes  are  essential  in  reaching  the  posterior  parts 
of  the  mouth.  The  "Schimmel"  needles  are  excellent,  but  do  not, 
however,  fit  every  syringe.  For  pressure  anesthesia  special  needles 
are  required,  and  may  be  bought  at  the  depots,  or  cjuickly  prepared 
by  grinding  ofl  the  steel  needle  at  its  point  of  reinforcement.  The 
sterile  needle  should  be  kept  in  w^ell-protected  glass  containers.  The 
needles  are  sterilized  after  each  use  by  l)oiling  in  plain  water,  dried  with 
the  hot  air  syringe,  and  immediately  transferred  to  a  covered  sterile 
glass  dish.  The  sterile  needles  should  not  be  again  touched  with  the 
fingers,  and  the  customary  wire  insertion  is  unnecessary. 


TECHNIQUE  OF  INJECTION 

Various  methods  of  injecting  the  anesthetic  solution  about  the  teeth 
are  in  vogue.  For  the  sake  of  convenience  we  mav  divide  them  as 
follows : 

The  subperiosteal  injection. 

The  peridental  injection. 

The  intraosseous  injection. 

The  perineurial  injection. 

The  injection  into  the  pulp. 
Before  starting  anv  surgical  interference  in  the  mouth,  the  field  of 
operation  should  be  thoroughly  cleansed  with  an  antiseptic  solution.    A 
thin  coat  of  the  official  tincture  of  iodin  painted  over  the  surface  is  very 


TECHNIQUE  OF  INJECTION  637 

useful  for  (his  purpose.  After  the  diap^nosis  is  made  the  method  of  injec- 
tiou  best  suited  for  the  case  ou  hand  is  then  decided.  The  necessary 
quantity  and  the  concentration  of  the  anesthetic  solution  is  now  prepared, 
and  the  syringe  and  liypodermic  needle  fitted  ready  for  the  work.  To 
facilitate  the  ready  penetration  of  the  needle  into  the  tissues,  its  point 
may  be  coated  with  carbolated  vaselin.  The  correct  position  of  the 
syringe  in  the  hands  of  the  operator  and  its  proper  manipulation  is  an 
important  factor,  and  has  to  be  acquired  by  practice.  The  hand  holding 
the  syringe  is  exclusively  governed  in  its  movement  by  the  M-rist,  so  as 
to  allow  delicate  and  steady  movements,  and  the  fingers  must  be  trained 
to  a  highly  developed  sense  of  touch.  The  syringe  is  filled  by  drawing 
the  solution  up  into  it ;  it  is  held  perpendicularly,  point  upward,  and  the 
piston  is  pushed  until  the  first  drop  appears  at  the  needle  point,  which 
precaution  prevents  the  injection  of  air  into  the  tissue. 

The  Subperiosteal  Injection. — The  subperiosteal  injection  about  the 
root  of  an  anterior  tooth  is  best  started  by  inserting  the  needle  midway 
between  the  gingival  margin  and  the  approximate  location  of  the  apex. 
The  pain  of  the  first  puncture  may  be  obviated  by  a  fine,  very  sharp- 
pointed  needle,  the  simple  compression  of  the  gum  tissue  with  the  finger- 
tip, by  holding  a  pledget  of  cotton  saturated  with  the  prepared  anes- 
thetic solution  on  the  gum  tissue  for  a  few  moments,  or  by  applying  a 
very  small  drop  of  liquid  phenol  on  the  point  of  puncture.  The  needle 
opening  faces  the  bone,  the  syringe  is  held  in  the  right  hand  at  an  acute 
angle  with  the  long  axis  of  the  tooth,  while  the  left  hand  holds  the  lip 
and  cheek  out  of  the  way.  After  puncturing  the  mucosa,  a  drop  of  the 
liquid  is  at  once  deposited  in  the  tissue,  and  the  further  injection  is 
painless.  Slowly  and  steadily  the  needle  is  forced  through  the  gum 
tissue  and  periosteum  along  the  alveolar  bone  tow^ard  the  apex  of  the 
tooth,  depositing  the  fluid  under  pressure  close  to  the  bone  on  its  upward 
and  return  trip.  The  continuous  slow  moving  of  the  needle  prevents 
injecting  into  a  vein.  A  second  injection  may  be  made  by  partially 
withdrawing  the  needle  from  the  puncture  and  swinging  the  syringe 
anteriorly  or  posteriorly,  as  the  case  may  be,  from  the  first  route  of 
the  injection.  This  latter  method  is  especially  indicated  in  injecting  the 
upper  molars.  After  removing  the  needle,  place  the  finger  tip  over  the 
puncture  and  slightly  massage  the  injected  area.  A  circular  elevation 
outlines  the  injected  field.  The  naturally  pink  color  of  the  gum  will 
shortly  change  to  a  white  anemic  hue,  indicating  the  physiological 
action  of  the  adrenalin  on  the  circulation.  No  wheal  should  be  raised 
by  the  fluid,  as  that  would  indicate  superficial  infiltration  and  conse- 
quently failure  of  the  anesthetic. 

As  the  liquid  requires  a  definite  length  of  time  to  pass  through  the 
bone  lamina  and  to  reach  the  nerves  of  the  peridental  membrane  and 
the  pulp,  from  five  to  ten  minutes  should  be  allowed  before  the  extrac- 
tion is  started.    The  length  of  time  depends  on  the  density  of  the  sur- 


638  LOCAL  ANE6TIIE6IA 

rouiKlin<>"  structure  of  the  tooth.  The  progress  of  the  anesthesia  may 
be  tested  with  a  fine  pointed  probe,  and  its  completeness  indicates  the 
time  when  the  extraction  should  be  started. 

The  upper  eiojht  anterior  teeth  usually  recjuire  a  lal)ial  injection  only, 
while  the  molars  recjuire  both  a  buccal  and  a  palatal  injection,  using 
a  slightly  curved  needle  for  this  purpose.  Buccally  the  injection  is  made 
midway  between  the  mesial  and  distal  root,  and  on  the  palatal  side 
over  the  palatal  root. 

The  lower  eight  anterior  teeth  are  comparatively  easily  reached  by  the 
injection.  The  straight  needle  is  inserted  near  the  apex  of  the  tooth, 
the  syringe  is  held  in  a  more  horizontal  position,  and  the  injection  pro- 
ceeds now  as  outlined  above. 

The  lower  molars  require  a  buccal  and  lingual  injection.  The  curved 
needle  is  inserted  midway  between  the  roots,  the  gum  margin,  and  the 
apices.  The  external  and  internal  obli(|ue  lines  materially  hinder  the 
ready  penetration  of  the  injected  Huid,  and  therefore  ample  time  should 
be  allowed  for  its  absorption. 

If  two  or  more  adjacent  teeth  are  to  be  removed,  the  injection  by 
means  of  infiltrating  the  area  near  the  gum  fold  directly  over  the  apices 
of  the  teeth  is  to  be  preferred.  It  is  advisable  to  use  a  one  inch  needle 
for  this  purpose,  holding  the  syringe  in  a  horizontal  position,  so  as  to 
reach  a  larger  field  with  a  single  injection. 

The  injection  into  inflamed  tissue,  into  an  abscess,  and  into  phleg- 
monous infiltration  about  the  teeth  is  to  be  avoided.  The  injection 
into  engorged  tissue  is  very  painful;  the  dilated  vessels  quickly  absorb 
cocain  without  producing  a  complete  anesthesia,  and  general  poisoning 
may  be  the  result.  In  purulent  conditions  the  injection  is  decidedly 
dangerous,  as  it  forces  the  injection  beyond  the  line  of  demarcation.  If 
the  abscess  presents  a  definite  outline,  the  injection  has  to  be  made  into 
the  sound  tissue  surrounding  the  focus  of  infiltration.  If  a  tooth  is 
affected  with  acute  diffuse  or  purulent  pericementitis,  a  distal  and  a 
mesial  injection  usually  produce  successful  anesthesia  by  blocking  the 
sensory  nerve  fibers  in  all  directions. 

Peridental  Anesthesia. — Teeth  or  roots  standing  singly,  or  teeth  affected 
by  pyorrhea  or  similar  chronic  peridental  disturbances,  are  frequently 
quickly  and  satisfactorily  anesthetized  by  injecting  the  fluid  directly 
into  the  peridental  membrane.  This  method  is  known  as  peridental 
anesthesia,  and  its  technique  is  very  simple.  In  single- rooted  teeth 
a  fine  and  short  hypodermic  needle  is  inserted  under  the  free  margin  of 
the  gum,  or  through  the  interdental  papilla,  into  the  peridental  membrane 
between  the  tooth  and  the  alveolar  wall.  Sometimes  the  needle  may 
be  forced  through  the  thin  alveolar  bone  so  as  to  reach  the  peridental 
membrane  direct.  To  gain  access  to  this  membrane  in  teeth  set  close 
together,  slight  separation  with  an  orange-wood  stick  or  other  suitable 
means  is  often  found  to  be  of  advantage.     Two  and  sometimes  three 


TECHNIQUE  OF  INJECTION  639 

injections  are  necessary.  To  force  the  lk|ui(l  into  the  membrane  usually 
re(iuires  a  hioher  pressure  than  that  which  is  necessary  for  injecting 
into  the  periosteum  covering  the  alveolar  process,  hut  the  cjuantity  of 
the  anesthetic  Ii(iuid  is  less  than  that  which  is  required  for  the  former 
injection.  Acute  inflammatory  conditions  of  the  peridental  membrane 
and  its  sequehi^  prohibit  the  use  of  this  method.  Peridental  anesthesia 
is  the  purest  form  of  local  anesthesia,  since  the  seat  of  the  nerve  supply 
of  the  tooth  is  very  quickly  reached,  and  as  a  consequence  the  results 
obtained  are  in  the  majority  of  cases  extremely  satisfactory,  provided 
that  general  conditions  justify  its  application. 

Intraosseous  Injection. — To  facilitate  the  passage  of  the  injected  fluid 
into  the  bone  structure  proper,  Otte,  in  1896,  recommended  a  method 
by  which  he  forces  the  anesthetic  solution  directly  into  the  spongy 
cancelloid  bone.  Otte  terms  this  procedure  the  intraosseous  method  of 
injection,  and  its  technique  is  described  by  him  as  follows:  After  the 
gum  tissue  is  thoroughly  cleansed  with  an  antiseptic  solution,  it  is  anes- 
thetized about  the  neck  of  the  tooth  in  the  usual  manner.  After  waiting 
two  or  three  minutes,  an  opening  is  made  into  the  gum  tissue  and  the 
bone  on  the  buccal  side  with  a  fine  spear  drill  or  a  Gates-Glidden  drill. 
The  opening  should  be  made  more  or  less  at  a  right  angle  with  the  long 
axis  of  the  tooth,  a  little  below  the  apical  foramen  in  single-rooted  teeth 
or  between  the  bifurcation  in  the  molars.  The  right-angle  hand-piece 
is  preferably  employed  for  this  purpose.  The  drill  should  be  of  the 
same  diameter  as  the  hypodermic  needle.  The  gum  fold  is  tightly 
stretched  to  avoid  laceration  from  the  rapidly  revolving  drill.  As  soon 
as  the  alveolar  process  is  penetrated,  a  peculiar  sensation  conveyed 
to  the  guiding  hand  indicates  that  the  alveolus  proper  is  reached,  and 
the  sensation  felt  by  the  hand  is  about  the  same  as  that  experienced  when 
a  burr  enters  into  the  pulp  chamber.  In  this  artificial  canal  the  close- 
fitting  curv'ed  needle  of  the  hypodermic  syringe  is  now  inserted,  and  the 
injection  is  made  in  the  ordinary  way.  The  quantity  of  fluid  used  is 
much  less  than  is  usually  needed  for  a  subperiosteal  injection.  The 
roots  of  the  teeth  are  embedded  in  a  sieve-like  mass  of  bone  tissue  (diploe), 
which  allows  a  ready  penetration  of  fluid  when  injected  under  pressure. 
Very  recently,  Masselink,  advocates  this  method  for  the  anesthetization 
of  any  tooth  in  the  mouth  either  for  the  purpose  of  extraction  or  the 
removal  of  its  pulp.  He  employs  a  No.  4-  round  bur  for  penetrating 
the  alveolar  plate  and  a  very  short  needle  (about  one-sixteenth  of  an 
inch)  with  a  dull  point  for  the  injection. 

Perineuria!  Injection. — For  the  anesthetization  of  a  number  of  teeth 
in  the  upper  or  the  lower  jaw,  conductive  anesthesia  by  means  of  peri- 
neurial  injection  is  preferably  employed.  The  perineuria!  injection  is 
made  near  the  point  of  exit  or  entrance  of  the  various  nerves  about  their 
respective  foramina.  To  anesthetize  all  the  teeth  of  one-half  of  the 
upper  jaw  four  injections  are  necessary,  i.  e.,  two  bucally  and  two  on 


640  LOCAL  ANESTHESIA 

the  palatal  side  of  the  hone.  A  one-inch  nee<lle  is  required  for  such 
work.  To  reach  the  many  small  branches  of  the  posterior  dental  nerves 
at  the  alveolar  foramina,  the  injection  is  made  huccally  over  the  ret^ion 
of  the  tuberosity  about  ^  inch  above  the  gint^ival  line  between  the  first 
and  second  molar  tooth.  The  second  injection  is  made  below  the 
infraorbital  foramen,  so  as  to  reach  the  middle  and  anterior  dental 
nerves.  With  the  index  finder  of  the  left  hand  the  foramen  is  approx- 
imately located  by  exerting  pressure  upon  the  ner\'e-exit.  The  lip  is 
lifted  up  with  the  middle  finger  of  the  same  hand  and  the  needle  is  now 
inserted  between  the  apices  of  the  cuspid  and  first  bicuspid  teeth.  The 
needle  is  slowly  pushed  forward  until  its  point  is  felt  beneath  the  finger 
tip.  To  reach  the  nerve  supply  of  the  hard  palate  one  injection  is  made 
near  the  posterior  palatine  canal,  and  the  other  near  the  foramina  of 
Scarpa.  The  great  palatine  nerses  pass  through  the  posterior  palatine 
canals  on  either  side  of  the  hard  palate.  The  canals  lie  about  three- 
eighths  of  an  inch  above  the  edge  of  the  alveolar  process  and  the  last 
molar  tooth.  They  move  posteriorly  with  the  eruption  of  the  successive 
teeth.  The  nasopalatine  nerves  pass  through  the  foramina  of  Scarpa 
(incisive  foramen),  which  are  situated  in  the  line  of  the  suture  of  the 
maxillary  bones.  If  an  imaginary  line  be  drawn  from  the  distal  borders 
of  the  two  cuspids  and  passing  over  the  hard  palate,  the  line  will  ordin- 
arily pass  through  the  foramina.  The  needle  should  be  inserted  directly 
back  of  the  papilla,  which  lies  posteriorly  between  the  central  incisor 
teeth. 

To  anesthetize  one-half  of  the  mandible,  three  injections  for  the 
deposition  of  the  anesthetic  solution  are  necessary.  The  first  injection 
is  applied  near  the  mandibular  foramen,  the  second  near  the  mental 
foramen,  and  the  third  into  the  incisive  fossa.  To  locate  the  mandibular 
foramen  in  the  mouth,  the  lingual  surface  of  the  ramus  is  palpated  with 
the  finger,  the  anterior  sharp  border  of  the  coronoid  process  is  easily 
felt  about  five-eighths  of  an  inch  posterior  of  the  third  molar.  The 
process  passes  downward  and  backward  of  the  third  molar,  and  enters 
into  the  external  oblicpie  line.  ^lesially  from  this  ridge  is  to  be  found  a 
small  triangular  concave  plateau,  which  is  facing  downward  and  outward, 
being  bound  mesially  by  a  distinct  bony  ridge  and  covered  with  mucous 
membrane.  As  there  is  no  anatomical  name  attached  to  this  space, 
Braun  has  called  it  the  retromolar  triangle  (trigonum  retromolare).  In 
the  closed  mouth  it  is  located  at  the  side  of  the  upper  third  molar,  and 
in  the  open  mouth  it  is  found  midway  between  the  upper  and  lower 
teeth.  Immediately  back  of  the  mesial  border  of  this  triangle,  directly 
beneath  the  mucous  membrane,  lies  the  lingual  nerve,  and  about  three- 
eighths  of  an  inch  farther  back  the  mandibular  nerve  is  to  be  found. 
This  last  nerve  lies  close  to  the  bone,  and  enters  into  the  mandibular 
foramen,  which  is  partially  covered  by  the  mandibular  spine. 

Before  starting  the  injection  the  patient  should  be  cautioned  to  rest 


TECHNIQUE  OF  INJECTION  641 

his  head  quietly  on- the  head-rest  of  the  chair,  as  any  sudden  movement 
or  interference  witli  the  hand  of  the  operator  may  he  the  cause  of  break- 
ing the  needle  in  the  tissues.  The  syringe,  provided  with  a  one-inch 
needle,  is  held  in  a  horizontal  position,  resting  on  the  occluding  surfaces 
of  the  teeth  from  the  cuspid  backM^ard  and  slightly  toward  the  median 
linie.  The  needle  is  to  be  inserted  three-eighths  of  an  inch  above  and 
the  same  distance  back  of  the  occluding  surface  of  the  third  lower  molar, 
the  needle  o})ening  facing  the  bone.  This  position  will  insure  the 
correct  direction  of  the  needle  point  so  as  to  reach  the  tissues  immediately 
surrounding  the  nerves,  and  not  lose  the  injection  in  the  adjacent  thick 
muscle  tissue.  The  needle  must  always  be  in  close  touch  with  the  bone, 
and  is  now  slowly  pushed  forward,  depositing  a  few  drops  of  fluid  on 
its  way  until  the  ridge  is  reached.  About  five  drops  of  fluid  are  injected 
in  this  immediate  neighborhood  for  the  purpose  of  anesthetizing  the 
lingual  nerve.  The  needle  is  now  pushed  very  slowly  forward,  always 
keeping  in  close  touch  with  the  bone  and  depositing  fluid  on  its  way, 
until  it  is  pushed  in  about  five-eighths  of  an  inch.  It  is  important  to 
feel  the  way  carefully  along  the  bony  wall  of  the  ramus,  as  the  needle 
may  have  to  pass  over  the  roughened  and  bony  elevations,  which  afford 
attachment  to  the  internal  pterygoid  muscle.  During  the  injection  the 
syringe  should  remain  in  the  same  horizontal  position  as  heretofore 
outlined.  Soon  after  the  injection,  paresthesia  of  one-half  of  the  tongue 
on  the  side  of  the  injection  occurs,  which  is  soon  followed  by  anesthesia 
of  the  mandibular  nerve.  Paresthesia  of  the  mucous  membrane  and 
half  of  the  lower  lip  is  also  established.  The  pulps  of  the  lower  teeth, 
including  the  cuspid  and  lateral  incisor  and  the  gum  tissue  on  both  sides 
of  the  jaw,  are  anesthetized,  including  a  part  of  the  anterior  floor  of 
the  mouth.  The  complete  anesthesia  of  the  two  nerves  also  anesthetizes 
the  whole  alveolar  process  in  this  region.  About  five  minutes  are  re- 
quired for  the  complete  anesthetization  of  the  lingual  nerve,  and  at  least 
fifteen  minutes  for  the  mandibular  nerve.  Braun  claims  that  the  injec- 
tion is  absolutely  free  from  danger,  while  Roemer  states  that  danger  may 
arise  if  the  whole  quantity  of  the  solution  should  accidentally  be  injected 
into  a  vein. 

Conductive  mandibular  anesthesia  is  possible  only  when  the  patient 
can  open  the  mouth  sufficiently  to  allow  the  ready  introduction  of  the 
syringe.  If  the  tissues  about  the  third  molar  are  highly  infiltrated  with 
inflammatory  exudates,  local  anesthesia  is  absolutely  prohibited. 

The  mental  foramen  lies  midway  between  the  superior  and  inferior 
border  of  the  body  of  the  mandible  on  its  external  surface,  usually 
below  the  second  bicuspid  teeth.  Its  opening  always  faces  posteriorly. 
An  injection  near  this  point  increases  the  anesthesia  in  the  bicuspid 
region.  The  incisive  fossa  is  a  shallow  depression  on  the  external 
surface  of  the  mandible  betw^een  the  cuspid  teeth.  It  may  be  located 
by  the  palpating  finger  immediately  above  the  chin.  A  number  of  small 
41 


642  LOCAL  ANESTHESIA 

foramina  are  found  in  this  region  for  the  passaji^e  of  nenes  and  initrient 
vessels.  The  lower  incisors  may  be  anesthetized  by  making  injections 
anteriorly  into  the  incisive  fossa  and  one  posteriorly  in  the  region  corre- 
sponding to  the  fossa.  Usually,  peridental  anesthesia  is  to  be  preferred 
for  these  teeth. 

Conductive  anesthesia  is  serviceable  if  a  number  of  teeth  have  to  be 
removed  at  one  visit.  It  should  be  borne  in  mind,  however,  that  in 
general  onlv  one-half  of  either  jaw  should  be  anesthetized  at  one 
sitting,  so  as  to  keep  the  quantity  of  the  injected  anesthetic  solution 
within  the  limits  of  ordinary  dosage. 

The  Injection  into  the  Pulp.— By  pressure  anesthesia,  pressure  cata- 
phoresis,  or  contact  anesthesia,  as  the  process  is  variously  termed,  we 
understand  the  introduction  of  a  local  anesthetizing  agent  in  solution 
by  mechanical  means  through  the  dentin  into  the  pulp  for  the  purpose 
of  rendering  this  latter  organ  insensible  to  pain.  Simple  hand  pressure 
with  a  suitable  instrument,  the  hypodermic  syringe  or  the  so-called  high 
pressure  syringe,  is  recommended  for  such  purposes.  Regarding  the 
principles  of  pressure  anesthesia,  it  should  be  remembered  that  we 
cannot  force  a  liquid  through  healthy  dentin  by  a  mechanical  device 
without  injury  to  the  tooth  itself.  If  a  cocain  solution  is  held  in  close 
contact  with  the  protoplasmic  fibers  of  the  dentin,  the  absorption  of 
cocain  takes  place  in  accordance  with  the  law  of  osmosis.  The  imbib- 
ition of  the  anesthetic  is  enhanced  by  employing  a  physiological  salt 
solution  as  a  vehicle.  On  the  other  hand,  living  protoplasm  reacts 
unfavorably  against  the  ready  absorption  of  substances  by  osmosis 
for  two  reasons:  (1)  Its  albumin  molecule  is  relatively  large  and  not 
easily  diffusible,  and  (2)  as  an  integral  part  of  its  life  it  possesses  "vital" 
resistance  toward  foreign  bodies.  These  latter  factors  are  sufficiently 
demonstrated  by  the  fact  that  it  is  very  difficult  to  stain  living  tissue. 
Dehydration  of  the  protoplasm  increases  the  endosmosis  of  the  anes- 
thetic solution  markedly. 

When  we  apply  the  same  "pressure"  anesthesia  upon  carious  dentin, 
the  above  statements  do  not  hold  good.  We  are  able  to  press  fluids 
quite  readily  through  carious  dentin.  We  must  bear  in  mind  that  such 
dentin  has  been  largely  deprived  of  its  inorganic  salts,  leaving  an 
elastic  spongy  matrix  in  position.  By  drying  out  this  dentin  and  then 
confining  the  anesthetic  solution  under  a  suitable  water-tight  cover, 
the  pressure  applied  by  the  finger  is  quite  sufficient  to  obtain  the 
results.  Colored  fluids  may  be  readily  pressed  through  such  dentin 
and  even  stain  the  pulp. 

In  teeth  not  fully  calcified  and  in  so-called  soft  teeth,  pressure  anes- 
thesia is  more  readily  olitained,  while,  according  to  Zederbaum,  the 
process  fails  in  "teeth  of  old  persons,  teeth  of  inveterate  tobacco  chewers, 
worn,  abraded,  and  eroded  teeth,  teeth  with  extensive  secondary  calcific 
deposits,  teeth  whose  pulp  canals  are  obstructed  by  pulp  nodules,  teeth 


TECHNIQUE  OF  INJECT  ION  (J43 

with  metallic  oxids  in  tubules,  teeth  with  leaky  old  fillin<;-.s,  [)adly  calci- 
fied teeth-  inainjy  all  from  one  and  the  same  eause,  namely,  clogged 
tubuli.  In  most  cases  no  amount  of  persistent  pressure  will  prove 
successful." 

From  the  foreg-oini;'  it  will  he  observed  that  the  so-called  high  pressure 
syringes  possess  little  merit  relative  to  pressure  anesthesia.  The  pressure 
which  can  be  produced  by  a  good  working  all-metal  syringe,  holding  it 
between  the  index  and  middle  fingers  and  forcing  the  piston  with  the 
thumb,  amounts  to  2o0  to  300  pounds  in  the  average  man.  The  pressure 
retpiired  in  pressure  anesthesia  to  produce  a  perfect  contact  is  usually 
much  less  than  the  above  force. 

Mcihods  of  Anesthetizing  the  Pulp. — 1.  The  pulp  is  wholly  or  partially 
exposed:  Isolate  the  tooth  with  the  rubber  dam  and  clean  it  with 
water  and  alcohol.  Excavate  the  cavity  as  much  as  possible,  and  if  the 
pulp  is  not  exposed,  dehydrate  with  alcohol  and  hot  air.  Saturate  a 
pledget  of  cotton  or  a  piece  of  spunk  with  a  concentrated  cocain  or 
novocain  solution,  place  it  into  the  prepared  cavity  and  cover  it  with 
a  piece  of  vulcanizable  rubber,  and  with  a  suitable  burnisher  apply 
slowly,  increasing  continuous  pressure  from  one  to  three  minutes.  The 
pulp  may  now  be  exposed  and  tested.  If  it  is  still  sensitive,  repeat 
the  process.  Loeffler  states  that  "this  pressure  may  be  applied  by 
taking  a  short  piece  of  orange  wood,  fit  it  into  the  cavity  as  prepared, 
and  direct  the  patient  to  bite  down  upon  this  with  increasing  force. 
In  this  way  we  can  obtain  a  well-directed  regulated  force  or  pressure, 
and  with  less  discomfort  to  the  patient  and  operator."  JNIiller  described 
this  process  as  follows:  "After  excavating  the  cavity  as  far  as  convenient 
and  smoothing  the  borders  of  it,  take  an  impression  in  modelling  com- 
pound, endeavoring  to  get  the  margins  of  the  cavity  fairly  well  brought 
out;  put  a  few  threads  of  cotton  into  the  cavity  and  saturate  them  thor- 
oughly with  a  5  to  10  per  cent,  solution  of  cocain,  cover  this  with  a 
small  bit  of  rubber  dam,  and  then  press  the  compound  impression 
down  upon  it.  We  obtain  thereby  a  perfect  closure  of  the  margin,  so 
that  the  liquid  cannot  escape  and  one  can  then  exert  pressure  with  the 
thumb  sufficient  to  press  the  solution  into  the  dentin." 

2.  The  pulp  is  covered  with  a  thick  layer  of  healthy  dentin:  With 
a  very  small  spade-drill  bore  through  the  enamel  or  direct  into  the 
dentin  at  the  most  convenient  place,  guiding  the  drill  in  the  direction  of 
the  pulp  chamber.  Blow  out  the  chips,  dehydrate  with  alcohol  and  hot 
air,  and  apply  the  syringe  provided  with  a  special  needle,  making  as 
nearly  as  possible  a  water-tight  joint.  Apply  slow  continuous  pressure 
from  two  or  three  minutes.  With  a  round  bur  the  pulp  should  now  be 
exposed,  and  if  still  found  sensitive,  the  process  is  to  be  repeated. 

Recently  a  method  has  come  into  vogue  which  allows  successful 
anesthetization  of  the  pulp  by  injecting  the  anesthetic  solution  around 
the  apex  of  the  tooth.     The  spongy  alveolar  process,  which  contains 


644  LOCAL  ANESTHESIA 

lymph  cliamiels,  allows  the  ready  penetration  oF  the  lluid.  The  iujeetion 
should  be  made  close  to  the  bone,  pushing  the  needle  slowly  toward  the 
apex,  while  the  fluid  is  deposited  drop  by  drop.  No  wheal  should  be 
raised  by  the  injection,  otherwise  the  benefits  of  the  pressure  from  the 
dense  gum  tissue  is  lost. 

According  to  Ilertwig,  the  protoplasm  of  the  cell  primarily  transfers 
irritation,  and,  secondly,  transmits  absorbed  materials.  Therefore,  the 
anesthetic  solution  has  to  pass  through  the  entire  dentinal  fiber  before 
the  nerve  tissue  of  the  pulp  proper  is  reached.  C\)nse(|uently  a  certain 
period  of  time  is  required  before  the  physiological  effect  of  the  anes- 
thetic is  manifested.  This  period  of  latency  is  dependent  upon  the 
thickness  of  the  intermediate  layer  of  dentin  or  bone.  The  successful 
anesthetization  of  the  pulp  depends  largely  upon  this  most  important 
factor  of  allowing  sufficient  time  for  the  proper  migration  and  action  of 
the  drug. 


LOCAL  ANESTHESIA  FOR  OPERATIONS  ABOUT  THE  MOUTH, 
EXCLUSIVE  OF  THE  EXTRACTION  OF  TEETH 

In  operating  about  the  mouth  for  an  abscess,  a  cystic  or  a  solid  tumor 
of  the  approximate  size  of  a  large  walnut,  a  malposed  tooth,  or  for  any 
other  purpose,  the  rhomboid  infiltration  according  to  Hackenbruch 
affords  the  simplest  means  of  producing  a  most  satisfactory  anesthesia. 
After  previously  cleansing  the  field  of  operation  with  an  antiseptic 
solution,  a  very  small  drop  of   phenol  is  placed  at  a  and  h  (Fig.  077) 

Fig.  677 


to  obtund  the  point  of  puncture  superficially.  The  needle  is  (piickly 
thrust  through  the  mucosa  at  a,  and  at  once  slow  pressure  is  exerted  on 
the  piston,  moving  the  needle  steadily  along  the  external  line  of  the 
tumor.  The  needle  is  now  partially  withdrawn,  without,  however, 
leaving  the  original  ])uncture,  and  a  second  injection  or  as  many  as 
may  be  needed  are  made  in  opposite  directions.     This  maneuver  is  now 


OPERATIONS  ABOUT  THE  MOUTH  045 

repeated  at  h,  and  thus  a  rirciiinscrilx'd  infiltration  of  tlu-  whole  tumor 
is  obtained.  If  tiie  tumor,  etc.,  is  very  hirge,  additional  punctures  and 
injections  may  he  made  as  outlined  in  the  schematic  drawino-.  After  ten 
to  fifteen  minutes'  waitin<i;  the  extirpation  of  the  tumor  may  be  l)egun. 
For  injecting  the  soft  tissues  other  than  the  gum,  a  1  per  cent,  novocain- 
adrenalin  solution — one  tablet  dissolved  in  2  c.c.  of  water — is  quite 
sufficient. 

The  anesthetization  of  the  soft  and  hard  palate  is  comparatively 
easily  accomplished.  The  injection  on  the  hard  palate  is  started  at  the 
gingival  i^^Vj,^  of  the  alveolar  periosteum  on  both  sides  of  the  jaw  toward 
the  median  line.  As  the  gum  tissue  is  extremely  dense,  great  force  is 
required  for  a  complete  infiltration  in  this  region,  and  only  small  quan- 
tities of  the  solution  are  required.  The  soft  palate  is  easily  infiltrated 
by  inserting  die  curved  needle  posteriorly  to  the  third  molar. 

Small  tumors  and  cysts  on  the  tongue  or  the  floor  of  the  mouth  are 
best  anesthetized  by  the  rhomboid  infiltration  of  Hackenbruch.  For 
the  complete  extirpation  of  a  ranula,  the  injection  is  made  into  the 
cyst  wall  near  the  periphery,  after  v^'hich  the  cyst  is  slit  open  and  a 
small  quantity  of  the  anesthetic  solution  is  injected  into  the  inner  surface 
of  the  cyst.  Large  cysts,  tumors,  and  major  operations  on  the  tongue 
require  the  anesthetization  of  both  lingual  nerves.  In  injecting  and 
operating  on  the  floor  of  the  mouth,  the  index  finger  of  the  left  hand 
should  be  placed  on  its  external  surface  as  a  guide  to  the  needle  or  the 
knife. 

Local  anesthesia  is  indicated  in  all  minor  and  in  relatively  many 
major  operations  on  the  mucous  surfaces,  the  skin,  and  the  teeth. 
Local  anesthesia  is  not  a  substitute  for  general  anesthesia;  its  usefulness 
is  materially  increased  by  familiarizing  one's  self  with  the  modern 
methods  of  its  production  and  with  a  perfect  mastering  of  the  technique. 
The  danger  of  poisoning  has  been  practically  eliminated  by  using  iso- 
tonic solutions  containing  a  relative  small  percentage  of  the  anesthetic 
in  combination  with  the  alkaloid  of  the  suprarenal  capsule.  Even 
if  the  danger  of  general  narcosis  is  small  under  the  very  best  conditions, 
the  danger  from  local  anesthesia  is  always  less.  The  greater  majority  of 
all  dental  operations  can  be  safely  carried  out  under  local  anesthesia, 
provided  the  operator  has  acquired  a  complete  working  knowledge  of 
the  various  components  which,  as  a  whole,  constitute  this  important 
branch  of  dental  therapeutics. 


CHAPTER    XIX 
PLANTATION  OF  TEETH 

By  LOUIS  OTTOFV,  D.D.S. 

The  transplantation  of  a  tooth  signifies  the  insertion  of  a  natural 
tooth  into  a  natural  alveokis  other  than  the  one  it  ()ri<i;inally  occupied. 
The  tooth  may  be  an  old  and  dry  specimen  transplanted  into  an  alveolus 
from  which  a  tooth  has  been  recently  removed,  or  it  may  be  a  freshly 
extracted  tooth  transplanted  from  one  part  of  the  mouth  of  an  individual 
to  another  part  of  the  mouth  of  the  same  individual,  or  it  may  be  a 
freshly  extracted  tooth  transplanted  from  the  mouth  of  one  person 
into  that  of  another. 

Replantation  sitrnifies  the  replacing  of  a  tooth  in  the  alveolus  whence 
it  had  been  removed  by  design  or  accident.  The  operation  may  be 
performed  at  once  or  at  any  time  before  the  socket  is  filled  with  new 
tissue. 

Under  the  term  implantation  are  included  all  those  operations  which 
involve  the  formation  of  an  artificial  alveolus  for  the  reception  of  the 
root  of  a  human  tooth.  The  operation  of  altering  the  size  or  form 
of  an  existing  alveolus  to  receive  a  tooth  belongs  to  this  class,  although 
it  is  a  combination  of  transplantation  and  implantation. 

The  operation  of  replantation  probably  far  antedated  that  of  trans- 
plantation, as  the  latter  preceded  implantation,  but  its  definite  history 
is  unknown.  It  is  safe  to  presume  that  it  has  been  practised  ever  since 
mankind  conceived  of  the  natural  healing  power  of  the  body.  Even 
when  performed  with  crudity  and  without  any  clear  comprehension 
of  the  mode  of  repair,  favorable  results  have  been  reported.  The 
operation  is  at  present  an  uncommon  one;  the  condition  for  the  relief 
of  which  it  was  at  one  time  practised  with  comparative  frequency, 
chronic  alveolar  abscess,  has  been  found  amenable  to  less  radical 
treatment. 

The  operation  of  transplantation  is  first  noted  in  the  writings  of 
Ambroise  Pare  in  the  sixteenth  century,  although  credit  has  generally 
been  given  to  Dr.  John  Hunter,  who  gave  the  subject  considerable 
attention.  Hunter's  experiment  of  implanting  a  tooth  in  the  comb 
of  a  cock  is  classical.  The  records  of  the  operation  do  not  exhibit 
any  great  measure  of  success  attending  it.  Hunter  noted  cases  of 
transplantation  of  dead  teeth  which  remained  for  years. 

No  one  disputes  with  Dr.  Younger,  of  Paris,  the  authorship 
(646) 


BIOLOGICAL  COXDITIOXS  IN  PLANTATION 


647 


of  the  operatit)!!  of  implantation.  The  date  of  his  first  operation 
was  June  15,  1S85,  ahhough  Bourdet  in  1780  was  the  first  to  mention 
the  operation,  statin<i|;  that  "irresponsible  persons  claim  to  make  a 
socket,  and  implant  into  it  a  tooth."  An  attempt  at  partial  implanta- 
tion is  recorded  in  Dental  Cosmos,  vol.  xix,  p.  25S. 

In  order  that  an  intelligent  conception  may  be  had  of  the  intimate 
nature  of  the  biological  conditions  which  surround  the  teeth  after  inser- 
tion bv  either  of  these  operations,  it  is  essential  to  study  the  general 
processes  which  attend  the  repair  of  tissues,  and  their  behavior  toward 
foreign  bodies. 


Fig.  6781 


Fig.  679 


15        1 

A  tooth  and  its  normal  attachment  and  vas- 
cular supply:  1,  1,  apical  pericementum  in  which 
is  seen  the  main  pericemental  artery.  5;  2,  2,  anas- 
tomosing bloodvessels  or  channels  of  the  alveolar 
walls;  3,  3.  the  marginal  anastomosis  of  alveolar 
and  pericemental  arteries. 


Conditions  following  replantation:  1,  1', 
the  pericementum  and  inflammatory  effu- 
sion between  pericementum  and  alveolar 
walls;  2.  2.  source  of  blood  supply  to  the 
area  of  repair;  3,  3,  terminations  of  alveolar 
arteries;  5,  obliterated  apical  artery. 


As  all  of  these  operations  are  performed  under  the  strictest  antiseptic 
precautions,  the  consideration  of  bacterial  influence  is  omitted  at  this 
juncture.  As  it  is  impossible  to  secure  specimens  which  would  show 
these  several  parts  in  their  true  relations,  the  illustrations  are  neces- 
sarily diagrammatic  and  theoretical. 

Fig,  67S  exhibits  a  longitudinal  section  of  an  incisor,  its  attachments 
and  support,  together  with  its  vascular  supply,  in  its  normal  relations, 


1  Figs.  678  and  6S1  are  from  drawings  bv  Dr.  H.  H.  Burchard. 


64S 


PL  AX  TAT  I  ON  OF   rKETIl 


the  bloodvessels  from  the  periceineiitiini  anastoinosinoj  with  those  of 
the  alveolar  periosteum.  The  perieemental  space  is  filled  with  fibrous 
tissue.  To  avoid  coufusion  the  nerves  and  veins  have  been  omitted. 
Fip;.  ()79  represents  the  c-onditions  followino'  re])lantation.  The  tooth 
has  been  sterilized  and  its  pulp  canal  hermetically  sealed.  The  peri- 
cemental bloodvessels  have  been  destroyed  in  extraction.  Portions  of 
the  ])ericementum  are  seen  clingintij  as  fibrous  remnants  to  the  cemen- 
tum.     The  remainder  of  the  alveolus  is  filled  with  inflanunatorv  eor- 


FiG.  680 


Fig.  G81 


Conditions  following  transplantation: 
1,  l',  embryonic  tissue  which  will  be 
organized  into  repair  tissue  replacing 
the  original  pericementum;  o,  obliterated 
apical  vessels. 


Conditions  following  implantation:  1,  1, 
alveolar  arteries;  2,  2,  gingi\al  margin;  3, 
inflammatory  still  unorganized  tissue  filling 
the  space  between  the  cementum  and  walls 
of  the  artificial  alveolus;  4.  4,  phagocytes, 
multinucleated  cells  attacking  cementum  of 
implanted  tooth;  5,  obliterated  apical 
vessels. 


puscles.  The  vascular  supply  to  the  regenerated  pseudo-pericementum 
is  derived  first  from  the  vessels  of  the  alveolar  periosteum  via  the  alveolar 
process. 

Fig.  OSO  sho%vs  the  conditions  existing  soon  after  the  o])eration  of 
transplantation.  The  mechanical  violence  of  extraction  has  irregularly 
enlarged  the  natural  alveolus.  The  tooth,  its  apex  rounded,  is  shown 
with  the  blunted  extremity.  The  vascular  su])ply  is  similar  to  that 
of  Fig.  G79.     The  alveolar  space  is  filled  with  inflammatory  corpuscles. 

Fig.  681  exhibits  the  conditions  probably  existent  soon  after  an 
implantation  operation.     The  vascular  supply  is  the  same  as  shown 


REPLANTATION  AND  TRANSPLANTATION  G49 

in  Figs.  (17',)  and  (iSO.  Instead  of  haviiio-  a  layer  of  periosteal  l)one, 
the  foriuatioii  of  the  artificial  alveolus  is  into  the  spongy  medullary 
bone.  The  artilieial  alveolus,  beini>'  necessarily  difl'erent  in  size  and 
outline  from  the  tooth,  is  filled  with  inflannnatory  products.  Some  of 
the  cells,  becoming  nndtinucleated,  are  seen  to  be  exercising  their  phago- 
cytic— in  this  connection,  rcsorptive — function  upon  the  cementum. 


REPLANTATION  AND  TRANSPLANTATION 

Replantation. — In  the  present  state  of  dental  practice  the  following 
conditions    may    be    regarded    as    warranting    replantation: 

1 .  ^Yllen  a  tooth  has  been  dislodged  l)y  traumatism,  a  blow  by  a 
ball,  club,  or  fall,  etc. 

2.  ^Yhen  a  tooth  has  been  accidentally  removed  by  the  slipping  of 
the  forceps  din'ing  the  performance  of  a  dental  extraction. 

3.  When  some  disease,  otherwise  incurable,  affects  either  the  root 
or  some  portion  of  its  alveolus. 

The  first  two  causes  are  practically  the  most  frecjuent  under  which 
replantation  is  justifiable. 

In  case  a  tooth  has  thus  been  dislodged  and  found,  it  should  at  once 
be  cleansed  of  all  foreign  matter  and  then  be  carefully  examined  for 
fractures  or  other  injury.  Any  cavities  present  should  be  filled,  the 
contents  of  the  root  canal  removed,  and  the  space  filled  in  the  manner 
described  later;  fractured  or  abraded  portions  or  surfaces  are  to  be 
made  smooth,  and  the  tooth  placed  in  an  antiseptic  solution.  A  careful 
examination  of  the  socket  should  then  be  made.  It  will  be  noticed 
when  the  accident  has  befallen  a  young  individual,  that  as  a  result 
of  the  flexibility  of  the  bone,  the  alveolar  process  is  seldom  fractured — 
an  accident  more  prone  to  happen  in  adult  life. 

Some  discrimination  should  be  exercised  as  to  the  promptness  w4th 
which  to  replant  the  tooth.  If  there  is  considerable  inflammation 
as  the  result  of  injury,  it  is  not  advisable  to  replace  the  tooth  imme- 
diately. In  that  event  the  socket  should  be  made  aseptic  and  if  possible 
normal  hemorrhage  reestablished.  As  a  general  rule,  several  days 
should  be  allowed  to  intervene  when  the  inflammation  is  excessive; 
otherwise  a  tooth  may  be  replaced  at  any  time  as  soon  as  it  has  been 
prepared. 

The  governing  pathological  principle  is  as  follows:  Immediately 
after  an  injury,  a  certain  amount  of  inflammation  takes  place  and  there 
is  retrograde  metamorphosis — a  destruction  or  breaking  down  of  tissue; 
and  this  is  not  the  most  favorable  time  to  expect  re-attachment  to  take 
place.  As  a  rule,  within  a  few  days  a  building-up  process,  constructive 
metamorphosis,  has  set  in,  and  the  replacement  of  a  tooth  at  this  time 
is  likely  to  be  followed  by  more  favorable  results.     This  period  sets  in 


050  rLAXTATKJX   OF   TEETH 

at  any  time  from  three  days  to  a  week,  the  S(K-ket  l)eiii<,'  then  j)artially 
filled  with  aetive  living  cells.  Just  prior  to  the  replacement  of  the 
tooth  the  socket  and  the  gum  surrounding  it  having  been  cleansed  and 
sterilized,  the  tooth  itself  being  brought  forth  from  its  antisej^tic  medium, 
it  must  be  promptly  replanted.  As  a  rule,  constant  but  not  severe 
pressure  will  permit  the  tooth  to  assume  its  original  position  in  the 
socket,  although  sometimes  it  is  necessary  to  remove  a  })art  of  the  apex 
of  the  root  or  slightly  deepen  the  socket  by  means  of  a  suitably  shaped 
bur.  It  happens  occasionally  that  the  location  of  the  tooth  and  the 
general  surroundings  are  such  that  a  tooth  like  this  may  be  retained 
without  any  further  attachment,  but,  as  a  rule,  it  is  not  safe  to  trust 
to  uncertainties  regarding  the  retention  of  the  tooth.  An  impression 
of  the  tooth  and  its  neighbors  can  be  quickly  secured  with  Melotte's 
compound  or  in  clay,  a  die  is  easily  made,  from  which  a  cap,  such  as 
will  be  described,  is  quickly  made. 

It  is  needless  to  dwell  upon  the  second  cause  mentioned.  Xo  dentist 
can  ever  be  excused  for  accidentally  removing  a  sound  tooth,  but  in 
case  the  accident  does  happen  the  above  procedure  is  indicated. 

The  opportunities  enumerated  under  the  third  section  are  also, 
fortunately,  exceedingly  rare.  The  cases  in  which  formerly  replantation 
was  resorted  to,  on  the  ground  that  the  case  was  incurable,  are  now 
much  less  frecjuently  met  with,  and  when  they  are  encountered  they 
often  yield  to  treatment,  which  is  now  more  clearly  understood — such  as 
amputation  of  the  root,  removal  of  the  necrosed  portion  of  the  alveolar 
process,  etc.  When,  however,  it  has  been  decided  to  extract  a  diseased 
tooth  and  to  replant  it,  diseased  portions  of  the  root  should  be  removed 
and  a  sufficient  time  allowed  to  elapse  before  replantation  for  the 
socket  and  tissues  to  have  assumed  a  healthy  aspect,  even  if  this  should 
necessitate  the  enlargement  of  the  socket. 

In  case  of  pyorrhea  alveolaris,  which  sometimes  has  been  suggested 
as  coming  under  this  class,  treatment  by  re})lantation  is  out  of  the 
question,  provided  the  case  has  made  sufficient  progress  to  suggest 
such  a  course.  Replantation  implies  the  presence  of  a  socket,  and 
when  pyorrhea  alveolaris  has  made  any  great  degree  of  progress,  the 
socket  is  wanting.  Hence  it  is  but  in  rare  cases  that  an  attempt  to 
cure  by  this  method  is  justifiable. 

Dr.  Louis  Jack*  has  recorded  marked  success  in  several  cases  attend- 
ing an  operation  of  modified  replantation  for  the  cure  of  some  of  the 
earlier  phenomena  of  phagedenic  pericementitis,  notably  the  common 
malposition  due  to  what  has  been  termed  voluntary  tooth  movement. 

Transplantation. — There  is  a  broader  range  for  the  practice  of  trans- 
plantation than  either  of  the  other  operations  treated  in  this  chapter. 
As  has  been  seen,  replantation  is  limited  in  its  application,  and  implan- 

1  See  Transactions  Academy  of  Stomatology,  1895. 


Ph'lil'Ah'ATJOX   OF    TKKTII    FOli   I'LAXT  AT  ION  Gol 

tation  must,  from  llic  nature  of  tlie  ojjcration,  ho  al.s<i  confined  to  a 
conij)aratively  circiunscrihed  sphere. 

Tlie  operation  may  be  performed  at  any  period  of  an  individual's 
life,  although,  as  a  rule,  young,  vigorous,  and  mature  adult  life  ofi'ers 
the  greatest  promise  of  success.  Any  socket  in  any  part  of  the  mouth, 
when  placed  in  a  healthy  condition,  is  a  more  or  less  favorable  location 
for  the  reception  of  a  tooth  about  to  be  transplanted.  It  is  true  that 
sometimes  a  socket  needs  to  be  enlarged  or  deepened  for  this  purpose, 
but  this  is  a  comparatively  simple  matter.  Before  the  advent  of  the 
intelligent  practice  of  crown-and-bridge  work,  treatment  of  diseases 
of  the  pulp  and  peridental  membrane,  the  bleaching  of  teeth,  and  the 
intelligent  practice  of  orthodontia,  transplantation  was  resorted  to  as 
a  remedy  for  the  correction  of  many  trivial  disorders.  In  the  light 
of  the  present  day,  transplantation  is  confined  to  sockets  whence  teeth 
have  been  removed  for  any  cause  which  could  not  be  remedied  by  some 
other  method  of  treatment — sockets  which  remain  as  the  result  of 
the  loss  of  teeth  from  accident  of  any  kind  (the  lost  teeth  not  having 
been  recovered) ;  from  which  roots  beyond  salvation  have  been  extracted ; 
from  which  diseased  teeth  must  be  removed;  from  which  roots  have 
been  removed,  having  carried  crowns  or  having  served  as  abutments 
for  bridges  until  their  period  of  usefulness  has  passed. 

The  same  rule  laid  down  for  the  care  of  a  socket  previous  to  replan- 
tation holds  good  for  transplantation;  namely,  that  inflammation  must 
be  reduced,  and  the  tooth  transplanted  into  the  socket  at  a  time  when 
progressive  constructive  metamorphosis  is  taking  place.  This  period 
is  stated  as  usually  from  three  to  seven  days  after  the  removal  of  the 
tooth.  In  instances  where  considerable  disease,  such  as  a  chronic 
alveolar  abscess  of  years'  standing  has  been  present,  even  a  longer 
time  should  be  allowed  to  intervene  before  transplantation. 


PREPARATION  OF  TEETH  FOR  PLANTATION 

With  the  exception  of  such  special  directions  as  are  necessary  in 
each  class  of  the  operations  described  in  this  chapter,  the  following 
general  directions  are  applicable  to  all  cases : 

The  Scion  Tooth. — For  replantation  a  recently  dislodged  tooth  is 
supposed  to  be  at  hand,  hence  there  is  a  fresh  tooth.  For  transplanta- 
tion it  is  implied  that  the  tooth  is  either  at  hand  or  about  to  be  secured, 
but  in  a  case  of  transplantation  or  implantation  the  age  of  the  tooth 
may  be  unknown  and  indefinite.  Teeth  have  been  planted  w^hose 
age  and  origin  have  been  absolutely  unknown,  and  they  have  become 
firm  in  their  new  locations.  Nevertheless  it  seems  reasonable  to  take 
the  ground  that  whenever  it  is  possible,  teeth  should  be  fresh  and  some- 
thing of  their  previous  environment  should  be  known.     There  are  no 


652  PLANTATION  OF  TEETH 

cases  on  record  where  disease  has  been  transmitted  thntn^h  the  medium 
of  a  planted  tooth,  aUliough  portions  of  the  early  literature  of  this 
subject  do  indicate  such  results.  The  principal  objection  to  old  and 
dry  teeth  is  that,  the  water  having  been  evaporated,  these  teeth  are 
almost  invariably  fractured  or  cracked  from  shrinkage.  When  these 
fractures  extend  to  the  crown  portion,  the  enamel  frecjuently  chips 
off  within  a  short  time  after  the  tooth  has  been  planted;  while  in  some 
instances  the  entire  root  has  been  fractured.  Another  objection  to 
teeth  promiscuously  gathered  is  that  it  is  seldom  possible  to  find  teeth 
in  which  the  crowns  are  sufficiently  perfect  to  be  serviceable  and  to 
be  presentable  in  the  mouth.  The  crown  of  a  dry  tooth  permits  of 
but  slight  alteration  with  the  grinding  stone  or  sandpaper  disk  with- 
out endangering  its  integrity;  while  if  it  is  atl'ected  by  caries  to  such 
an  extent  as  to  recjuire  an  extensive  operation,  the  life  of  the  filling 
is  likely  to  be  of  shorter  duration  than  a  similar  operation  performed 
on  a  freshly  extracted  tooth  or  a  tooth  with  living  connections.  For 
this  reason  it  is  preferable  to  use  only  the  roots  of  teeth,  attaching  to 
them  artificial  crowns.  This  permits  the  selection  of  a  crown  suitable 
in  size,  color,  and  shape,  and  which  may  be  ground  for  articulating 
purposes — an  important  matter  in  these  cases. 

If,  therefore,  an  old,  dry  tooth  must  be  used,  let  it  be  carefully  selected 
with  regard  to  the  absence  of  checks  or  cracks  or  fractures,  and  if  it 
be  impossible  to  secure  a  tooth  with  such  a  crown,  let  there  be  selected 
a  good  root  to  which  a  crown,  as  described  later,  can  be  attached. 

If  a  freshly  extracted  tooth  can  be  secured,  even  though  the  crown 
may  ])e  slightly  carious,  the  necessary  filling  operation  is  advisable, 
and  such  a  tooth  should  be  used,  if  possi})le. 

Root-filling, — Roots  may  be  filled  either  from  the  apex  or  through 
an  opening  or  cavity  in  the  crown.  Gutta-percha  seems  to  answer 
all  the  necessary  purposes,  but  for  a  short  distance  from  the  apical 
extremity  it  is  well  to  fill  with  gold  wire  or  foil. 

Pericementum, — The  theory  that  the  pericementum  becomes  revivified 
does  not  seem  to  be  tenable;  at  least  the  proposition  that  life  is  main- 
tained in  the  pericementum  for  any  considerable  period  of  time  after 
the  tooth  has  been  removed  from  vital  attachment  is  not  in  accord 
with  general  physiological  laws,  although  periosteum  as  a  tissue,  main- 
tains its  vitality  for  a  time  after  separation.^  For  the  purpose  of  secur- 
ing an  attachment  there  is  no  necessity  for  the  presence  of  the  peri- 
cementum; but  it  is  reasonable  to  assume  that  the  nearer  to  natural 
states  the  root  and  the  socket  are  in,  the  more  favorable  will  be  the 
prognosis.  It  is,  therefore,  a  safe  rule  to  follow,  to  preserve  as  much 
of  the  pericementum  as  is  possible.  The  preservation  of  the  peri- 
cementum has  an  advantage  from  the  fact  that  after  the  tooth  has  been 

>  See  Ziegler's  General  I'athulogy. 


PREPARATION  OF  TEETH  FOR  PLANTATION  653 

planted,  the  poriccMiuMitiim  under  the  influences  of  l)()(hly  heat  and 
moisture  expands  and  thus  acts  in  the  nature  of  a  sponge  graft,  enabling 
the  tissues  more  Cjuickly  to  obliterate  spaces  which  are  present  and 
to  attach  themselves  to  the  root. 

Subsequent  Caxe  of  Planted  Teeth. — Numerous  methods  for  the  reten- 
tion of  planted  teeth  have  been  recommended  l)y  various  authors  at 
ditl'erent  times.  While  many  of  them  are  original  and  ingenious,  all 
are  to  be  condemned  except  those  means  which  look  to  the  firm,  rigid, 
innnovable  retention  of  the  planted  tooth  for  a  definite  period,  that 
of  surgical  repair.  Neither  the  rubber-dam  splint,  silk  ligature,  nor 
gold  or  other  metal  wire  comes  under  this  heading.  Planted  teeth 
must  be  retained  immovably  for  a  period  of  two  to  six  weeks,  occasionally 
from  two  to  eight,  ten,  or  twelve  weeks.  The  shortest  time  of  immobility 
consistent  wdth  subsequent  attachment  is  preferable.  The  tooth  to 
be  transplanted  or  implanted  should  be  fitted  after  preparation  in  a 
model,  made  from  an  impression  of  the  gum  w^here  the  tooth  is  to  be 
planted  and  of  the  adjoining  teeth,  as  shown  in  Fig.  682. 

Fig.  682  Fig.  683 


Model  showing  prepared  tooth  in  place:   (a)  gold  Model  showing  retention  cap  in  situ, 

filling  at  cervical  joint. 

An  impression  is  then  taken  of  it  and  of  the  adjoining  teeth  on  each 
side.  A  retention  cap  is  then  swaged  to  cover  the  grinding  surfaces 
of  three  or  more  teeth,  half  the  length  of  the  crown  on  the  labial  surface 
and  nearly  the  full  length  on  the  lingual  or  palatal  surface,  as  shown 
in  Fig.  683. 

The  cap  may  be  made  of  pure  gold,  platinum,  or  German  silver. 
The  gauge,  according  to  the  metal  used,  should  be  from  No.  32  to 
No.  38.  This  cap  is  cemented  upon  the  crowns  adjoining  the  planted 
tooth  in  such  a  manner  that  it  may  be  removed  without  disturbing 
the  planted  tooth.  The  operator  can  remove  the  cap  by  springing  the 
metal  away  from  the  teeth,  examine  the  condition  of  attachment  of 
the  planted  tooth,  and  replace  the  cap  if  it  should  be  necessary.  When 
the  articulation  interferes  with  the  retention  of  the  cap,  the  latter  may 
be  ligated  to  the  adjoining  teeth  in  addition  to  being  cemented  to  them, 
and  still  admit  of  removal  without  disturbing  the  planted  tooth.     There 


654  PLAXTATION  OF   TEETH 

is  at  present  no  method  of  lif^aturing  or  l)an(Jing  the  teeth  whir-h  will 
permit  removal  of  the  ligature  or  band  without  more  or  less  disturbance 
of  the  planted  tooth. 

Aside  from  the  necessity  of  immobility  for  a  certain  period,  the  planted 
tooth  and  surrounding  tissue  generally  require  but  little  attention. 
In  occasional  cases  the  tissues  may  be  stimulated  by  painting  the  gum 
with  a  mixture  of  ecjual  parts  of  tincture  of  aconite  root,  c-hloroform, 
and  iodin  paint  (the  latter  is  a  saturated  solution  of  iodin  in  alcohol), 
or  by  the  use  of  stimulating  mouth  washes,  notably  those  containing 
capsicum.  The  patient  should  be  cautioned  to  encourage  the  down- 
ward growth  of  the  gum  by  the  use  of  the  toothbrush,  to  prevent  the 
accumulation  of  remnants  of  food  or  saliva,  and  to  prevent  their 
subsefjuent  putrefaction  should  particles  become  unavoidably  lodged 
around  the  tooth  or  cap.  This  is  best  accomplished  by  using  a  camel's- 
hair  brush  dipped  in  hydrogen  dioxid  or  pyrozone,  electrozone,  phenol- 
sodique,  etc.,  and  washing  out  the  interstices  frefjuently.  A  syringe 
f)r  spray  from  an  atomizer  may  l)e  used. 

Artificial  Roots. — Experiments  have  been  performed  looking  toward 
the  use  of  roots  other  than  those  of  natural  teeth.  Roots  made  of 
ivory,  corrugated  or  perforated  porcelain,  lead,  gold,  platinum,  and 
other  metals  have  been  used.  The  writer's  experiments  in  this  direc- 
tion have  all  resulted  in  failure.  There  is  no  recorded  evidence  that 
any  have  resulted  successfully. 

Mode  of  Attachment. — As  to  the  mode  of  attachment  of  ])laMte(l  teeth 
the  subject  is  clouded  in  obscurity.     From  the  nature  of  the  conditions 

it  is  difficult   to  secure  definite  information. 
i-io-  684  Dr.   Younger  holds   to   the   belief   that   the 

pericementum  becomes  revivified,  and  hence 
the  attachment  is  almost  physiological.  It 
is  probable  that  the  filling  of  the  space 
around  the  root  of  the  tooth  with  compact 
bone  tissue  is  sufficient  to  account  for  the 
retention  of  the  tooth  by  bony  encapsula- 
tion or  ankylosis.  It  is  probable  that  a 
planted  tooth,  by  reason  of  the  absence  of 

An    implanted     tooth    in    situ:         ,i  i   •  e  i       i  xl  i:..; „„_; 

,  ^,  .  the    cushion    formed     bv    the    livmg   peri- 

a,  a,  excavations  of  the  cementum         •-  ^  ^  r>^    r  _ 

due  to  resorptive  process.  cementum,  causcs    iiiorc  or    less    irritation 

in  the  socket  through  the  impact  of  u.se  in 
mastication,  and  that  this  irritation  leads  to  resorption  of  the  root;  that 
in  this  resorption  and  the  subsequent  filling  up  of  these  resorbed  .surfaces 
are  found  reasons  for  the  success  of  the  operation.  Fig.  f)84,  at  a,  a, 
shows  how  a  partially  resorbed  root  may  be  retained  in  place.  The 
length  of  time  during  which  a  planted  tooth  is  retained  depends  entirely 
upon  the  rapidity  of  the  resorptive  process  and  the  activity  of  the  tissues 
in  maintaining  a  healthy  condition.     Replanted  and  transplanted  teeth 


PREPARATION  OF  TEETH  FOR  PLANTATION  655 

have  been  known  to  do  good  service  for  from  twenty  to  forty  years.  The 
time  of  the  observation  as  to  implanted  teeth  is  shorter,  the  oldest  cases 

being  less  than  twenty  years  old.  In  the  writer's  observations,  extend- 
ing over  a  period  of  nearly  eighteen  years,  a  numi)er  of  teeth  have  been 
noted  which  ha\e  been  retained  successfully  for  ten  years;  how  much 
longer  they  will  remain  serviceable,  and  what  percentage  of  success 
will  attend  later  cases,  will  require  further  time  to  determine.  Dr. 
Younger  has  had  successfully  implanted  teeth  under  observation,  at 
last  report,  for  eleven  years. 

Precautions. — There  is  no  special  danger  connected  with  any  of  the 
operations  described  in  this  chapter,  provided  the  usual  antiseptic 
precautions  are  observed  and  dangerous  anesthetics  avoided.  Aside 
from  these,  during  the  operation  of  replantation  and  transplantation 
no  special  skill  is  necessary;  certain  precautions  are,  however,  essential. 
Inasmuch  as  implantation  is  an  essentially  esthetic  operation,  it  should 
be  borne  in  mind  that  it  is  confined  principally  to  the  ten  anterior  teeth, 
and  that  it  is  more  frequently  performed  in  the  upper  jaw  than  in  the 
lower.  The  territory  involved  is  therefore  limited.  The  operator  who 
contemplates  forming  in  this  territory  a  socket  for  the  reception  of  the 
root  of  a  tooth  should  be  intimately  acquainted  with  the  anatomical 
and  histological  relationships  of  the  various  parts. 

In  the  first  place  it  should  be  remembered  that  when  alveolar  resorp- 
tion has  taken  place,  the  relative  depth  of  bone  is  considerably  less 
than  when  a  tooth  is  still  in  situ  and  surrounded  by  the  normal  alveolar 
process.  The  operator  must,  therefore,  not  penetrate  deeper  into  the 
bone  than  the  original  depth  of  the  socket  may  have  been.  Indeed, 
it  is  not,  as  a  rule,  necessary  to  penetrate  so  far. 

In  the  upper  jaw  the  principal  danger  in  making  a  socket  for  the 
reception  of  central  incisors  lies  in  the  proximity,  posteriorly,  of  the 
anterior  palatine  nerve,  artery,  and  vein,  which  have  their  exit  from 
the  bone  throucrh  its  foramen,  often  near  the  roots  of  these  teeth.  With 
the  lateral  incisor  the  principal  precaution  necessary  is  the  preservation 
of  the  labial  plate  of  the  alveolus.  If  the  lost  tooth  has  been  absent 
for  some  time,  and  much  resorption  has  taken  place,  it  is  sometimes 
impossible  to  drill  a  socket  so  that  the  tooth  has  a  proper  direction 
and  prominence  in  the  arch,  and  yet  be  able  to  secure  a  bone  covering 
for  its  labial  surface.  As  a  rule,  there  is  sufficient  process  in  the  canine 
region  to  enable  the  operator  to  secure  all  the  attachment  desirable. 
The  bicuspid  and  molar  regions  present  the  danger  of  perforation 
of  the  floor  of  the  ma:sillary  sinus.  This  is  liable  to  happen  anywhere 
from  the  first  bicuspid  to  the  second  molar.  Extreme  caution  should 
be  exercised  to  avoid  it.  In  two  instances  in  practice  the  perforation 
was  followed  by  no  unpleasant  complications.  Care  was  taken  not 
to  infect  the  sinus,  the  teeth  were  implanted  in  the  usual  manner,  and 
the  cases  resulted  successfully.     Subsequently  one  of  these  teeth  was 


656  PLANTATION  OF   T EFT II 

lost,  but  during  the    process   of    root    attachineiit    or  eneystnient  the 
perforiition  into  the  sinus  was  closed. 

In  the  lower  jaw  the  principal  difficulties  encountered  are  the  follow- 
ing: In  the  incisive  region  there  is  a  deficiency  of  alveolar  process, 
and  hence  much  difficulty  is  encountered,  at  times,  in  securing  a  suffi- 
ciently deep  bony  socket.  At  the  location  of  the  canine  tooth  the  lower 
jaw  becomes  broader  and  there  is  usually  sufhcient  room  to  enable 
the  making  of  a  good  socket.  In  the  premolar  region  the  principal 
precaution  necessary  is  in  regard  to  the  mental  foramen.  It  must 
be  borne  in  mind  that  normally  the  exit  of  the  nerves  and  vessels  at 
this  point  is  directly  below  the  second  bicuspid  tooth,  and  that  when 
resorption  of  the  alveolar  process  has  taken  place  this  foramen  is  often 
near  the  upper  border  of  the  jaw.  From  this  point  posteriorly  implanta- 
tions are  rarely  performed,  and  when  done  the  principal  precaution 
must  be  in  regard  to  the  inferior  dental  canal,  which  is  near  the  surface 
if  much  resorption  has  taken  place. 

Artificial    Crowns. — The    precautions    necessary    in    the    selection    of 

a  tooth  for  transplantation  or  implantation  have  been  noted,  and  it 

might  be  proper  at  this  time  to  describe  the  prepa- 

FiG.  685  ration  of  a  root  with  an  artificial  crown,  presuming 

that   it   is    only   in    rare    instances  that  a    suita])le 

entire    natural    tooth   can    be   obtained.     Attention 

was  called   to  the  necessity  of   securing   asepsis   of 

the  root,  and  the  filling  of  the  root  canals  has  been 

described.     The  most   suitable   form  of  crown  has 

.  ^     ,.       been  found   to  be   the  Logan,  which   is  ground   to 

Natural  root  with  arti-  _  _  . 

ficiai  crown.  suit  tlic  occlusiou  and  cemented  mto  the  root  canal 

without  much  regard  as  to  a  careful  fit  at  the  cervix 
of  the  crown  to  the  root.  After  the  cement  has  hardened,  the  margin 
between  the  root  and  crown  is  prepared  with  engine  burs,  and  a 
filling  of  gold  introduced,  making  a  circle  around  the  tooth.  When 
this  is  polished  down  there  is  a  perfect  gold  filling  level  with  the 
root  and  crown,  which  is  preferable  to  a  soldered  band  (Fig.  ()S5). 

A  similar  result  may  now  be  much  more  satisfactorily  obtained  by 
adapting  the  crown  to  the  root  end  with  casting  wax  and,  after  carefully 
trimming  to  shape,  withdrawing  the  crown  with  lid  attached,  investing 
the  whole  and  replacmg  the  wax  by  a  gold  casting  by  means  of  any  of 
the  modern  casting  machines. 


GENERAL  CONSIDERATIONS 

Asepsis. — The  operations  described  in  this  chapter  must  always  be 
performed  under  perfect  aseptic  conditions;  that  is,  the  hands  and 
person,  instruments  and  other  accessories,  the  tooth  about  to  be  planted, 


GENERAL  CONSIDERATIONS  657 

and   the   field   (if   surgical    operation   must  be  maintained    in  a  clean, 
aseptic  condition. 

Any  of  the  usual,  accepted  methods  can  be  resorted  to.  As  a  rule, 
however,  the  drugs  selected  for  this  purpose  should  not  be  of  an  irri- 
tating nature.  For  the  hands  and  person,  pure  soap  followed  by  a 
5  per  cent,  solution  of  carbolic  acid  is  sufficient.  The  instruments 
and  other  accessories  can  be  kept  free  from  inoculating  bacteria  by  the 
use  of  pyrozone,  formalin,  euthymol,  or  a  5  per  cent,  solution  of  carbolic 
acid.  The  use  of  bichlorid  of  mercury  in  the  proportion  of  1  part  to 
2000  of  water  is  also  permissible,  although  it  is  not  as  advisable  on 
account  of  its  irritating  nature.  The  sterilization  of  the  tooth  about 
to  be  planted  ditiers  according  to  circumstances.  A  tooth  whose  source 
is  unknown,  and  which  has  been  kept  in  a  dry  state  for  a  long  period, 
will  not  be  benefited  by  being  placed  into  an  antiseptic  solution  until 
just  prior  to  the  time  when  it  is  to  be  used.  Hence  dry  teeth  can  be 
kept  in  any  clean  box  covered  with  clean  cotton  until  they  are  ready 
for  use.  After  the  necessary  preparation  hereinafter  described,  the 
dry  tooth  should  be  placed  in  a  solution  of  glycerol  and  carbolic  acid 
(about  5  per  cent,  of  the  latter),  and  just  before  using,  it  can  be  placed 
in  a  pyrozone  solution  or  in  a  solution  of  carbolic  acid  and  water. 
Freshly  extracted  teeth  should,  of  course,  have  their  pulp  chambers 
and  root  canals  cleansed  and  hermetically  sealed,  and  then  be  placed 
at  once  in  fluid,  preferably  in  diluted  glycerol  to  which  a  few  drops  of 
carbolic  acid  have  been  added.  Teeth  and  roots  so  treated  have  been 
preserved  for  eight  years. 

The  field  of  operation  may  be  quickly  sterilized  and  cleansed  of 
adhering  mucus  by  mopping  the  surface  with  a  ball  of  cotton  saturated 
with  hydrogen  dioxid,  3  per  cent,  solution,  just  previous  to  operating. 

It  is,  of  course,  of  exceeding  importance  that  the  socket  into  which 
a  tooth  is  about  to  be  planted  shall  be  free  from  disease  germs  or  bacteria. 
As  a  general  rule,  flowing  blood  is  the  best  of  antiseptics,  washing  away 
any  bacteria  which  may  become  lodged  from  external  sources;  hence 
so  long  as  a  socket  is  constantly  being  filled  with  flowing  blood  during 
an  operation  but  little  further  care  need  be  bestowed  upon  it.  As 
a  general  rule,  the  socket  and  the  tissues  surrounding  it  will  react  more 
quickly  after  operation  the  less  the  medication  has  been;  hence  the 
very  slightest  and  mildest  of  antiseptics  are  indicated.  Zinc  chlorid 
2  to  5  grains  to  the  ounce  of  lukewarm  water,  hydrogen  dioxid,  3  per 
cent.,  or  the  5  per  cent,  solution  of  carbolic  acid  in  lukewarm  water, 
give  most  satisfactory  results.  These  solutions  will  be  found  quite 
sufficient  to  maintain  the  field  of  surgical  operation  aseptic. 

Anesthesia. — For  the  purpose  of  allaying  pain,  the  use  of  anesthetics 
is  justified  w^hen  imperatively  demanded;  but  unfortunately  in  certain 
cases  the  benefits  derived  are  frequently  outweighed  by  the  disadvantages 
accruing  from  their  use. 
42 


658  PLAXTATION  OF  TEETH 

Anesthetics  are  either  general  or  local.  An  operator  would  scarcely 
be  justihed  in  assuming  the  risks  attendant  up(jn  tiie  use  of  chloroform, 
ethylic  ether,  ethyl  bromid,  or  any  of  the  combinations  in  which  these 
anesthetics  are  administered.  Nitrous  oxid  would,  in  the  majority  of 
instances,  be  contraindicated  by  reason  of  the  shortness  of  the  period 
of  anesthesia  which  it  induces. 

There  do  not  appear  to  be  any  records  of  satisfactory  results  with 
hypnosis.     Local  anesthesia,  therefore,  is  the  means  generally  employed. 

The  method  adopted  has  usually  been  confined  to  the  injection  or 
other  introduction  of  cocain,  the  dose  being  variable,  but  usually  about 
5  to  15  minims  of  a  1  per  cent,  solution  of  the  hydrochlorid.  For  a  full 
description  of  the  technique  consult  Chapter  XVIII  on  Local  Anesthesia. 
A  serious  objection  has  been  noted  to  injection  through  the  gum,  viz., 
that  more  or  less  sloughing  or  destruction  of  the  tissues  may  result, 
and  this  is  very  unfavorable  for  subsequent  success.  In  replantation  or 
transplantation,  sufficient  anesthesia  is  often  obtained  from  the  wash 
used  in  cleansing  the  socket;  but  in  implantation  the  formation  of  the 
new  socket  is  often  an  exceedingly  painful  operation,  and  in  these  cases 
good  results  may  be  had  by  dipping  the  instrument  with  which  the 
socket  is  being  made  into  crystals  of  cocain,  and  thus  by  the  friction 
of  the  instrument  rubbing  it  into  the  parts  that  are  being  operated 
upon. 

The  subject  of  anesthesia  may  be  dismissed  with  the  sole  injunction 
that  its  use  should  be  resorted  to  only  in  those  instances  where  it  is 
absolutely  necessary.  The  majority  of  the  cases  of  plantation  are 
performed  with  no  more  pain  than  is  inflicted  in  filling  ojjerations. 

The  same  care  should  be  given  to  the  retention  of  transplanted  teeth 
as  is  given  to  the  retention  of  replanted  teeth.  Teeth  thus  carefully 
transplanted,  in  individuals  of  good  health,  often  remain  useful 
for  a  number  of  years.  In  the  past  insufficient  attention  has  been 
given  to  asepsis,  and  this,  coupled  with  the  fact  that  the  root  had 
not  always  been  properly  filled,  has  not  resulted  in  as  much  success 
as  is  attained  with  present  methods,  and  yet  transplanted  teeth  are 
"known  to  have  remained  in  a  healthy  and  serviceable  condition  for 
from  twenty  to  forty  years. 


THE  OPERATION  OF  IMPLANTATION 

Implantation,  in  order  to  yield  the  best  results,  should  be  confined 
to  mouths  which  are  habitually  clean  and  free  from  disease,  and  to  a 
part  of  the  individual's  life  during  which  the  power  of  the  developed 
mental  processes  is  not  impaired.  Unclean  personal  habits,  the 
excessive  use  of  stimulants,  and  occupations  calling  for  an  unusual 
expenditure  of  nerve  force  are  unfavorable.     A  suitable  case  having 


THE  or  KR  AT  ION  OF  IMPLANTATION  059 

been  selected,  an  impression  of  the  space  and  of  the  teetli  adjoininp^ 
it  is  taken.  A  phister  cast  is  made,  the  proper-sized  socket  drilled 
therein,  the  tooth  is  selected  and  prepared,  either  with  or  without  an 
artificial  crown  in  the  manner  previously  described,  the  occlusion  is 
adjusted,  and  a  retention  cap  is  made.  These  preliminaries  having 
been  satisfactorily  accomplished,  the  case  is  ready  for  the  operation. 
Under  the  heading  of  (leneral  Considerations  the  ((uestion  of  anesthesia 
has  been  already  treated. 

The  first  step  in  the  operation  is  the  making  of  an  incision  through 
the  ffum  tissue.  A  number  of  different  kinds  of  incisions  have  been 
recommended  by  different  operators,  nearly  all  of  them  looking  toward 
the  preservation  of  the  largest  amount  of  gum  tissue.  Some  recom- 
mend a  crucial  incision  X,  turning  back  the  four  corners  of  the  gum 
tissue.  Others  have  recommended  an  incision  in  the  shape  of  the 
letter  H,  turning  back  the  two  flaps  thus  made. 

The  principal  objection  to  all  of  the  incisions  recommended  lies  in 
the  fact  that  they  all  look  toward  the  preservation  of  the  gum  tissue 
equally  for  the  labial  and  lingual  surfaces;  while,  as  a  matter  of  fact, 
if  proper  provision  is  made  for  the  protection  of  the  cervical  line  on  the 
labial  surface,  the  lingual  surface  will  take  care  of  itself,  for  it  will  be 
noticed  in  cutting  through  the  gum  tissue  that  it  is  much  thinner  where 
it  reflects  over  the  alveolar  border  upon  its  labial  aspect  than  upon  its 
lingual.  Hence,  frequently,  if  no  attention  whatever  has  been  paid  to 
the  retention  of  gum  tissue  on  the  lingual  surface,  the  neck  of  the  tooth 
will  nevertheless  be  sufficiently  protected. 

Fig.  686 


Incision  in  guni  for  implantation. 

Another  serious  objection  to  an  incision  which  leaves  two  or  more 
points  or  margins  to  be  preserved,  is  that  the  tenacity  of  the  gum  tissue 
makes  it  utterly  impossible  to  preserve  these  various  flaps  and  pro- 
jections intact  from  the  cutting  instruments. 

The  writer's  method  consists  in  an  incision  resulting  in  one  flap, 
with  a  view  of  protecting  the  labial  surface  of  the  tooth  to  be  implanted, 
and  of  preserving  this  single  flap  from  injury  during  the  progress 
of  the  operation.  A  combination,  or  rather  a  modification,  of  the 
most  suitable  incisions  recommended  is,  therefore,  the  one  shown  in 
Fig.  686. 

This  incision  is  made  with  ordinary  chisels  as  shown  in  Fig.  687, 


660 


PLANTATION  OF  TEETH 


ciittiiiir  with  (lu-  clusfl  to  and  includincr  the  ])eri().st(nim,  hftiiicj  it  forward 
and  holding  it  out  of  the  way  of  the  operator  by  means  of  an  instrument 


Fig.  688 


similar  to  the  one  shown  in  Fig.  688.  The  operation 
thus  far  is  usually  simple  and,  as  a  general  rule,  not 
very  painful.  The  drilling  of  the  socket  varies  with  dif- 
ferent individuals  according  to  the  density  of  the  bone, 
the  length  of  time  that  the  tooth  has  been  out,  etc.  In 
some  instances,  the  reamer  or  trephine  or  knife  pro- 
gresses rapidly,  while  in  others  the  progress  is  very  slow, 
or  sometimes  variable  as  the  instrument  enters  into 
medullary  spaces  or  passes  through  the  more  or  less  dense 
partitions  which  divide  these  medullary  spaces  from 
each  other. 

The  operator  will  determine  during  the  operation, 
by  the  progress  he  is  making  with  different  instruments, 
which  are  the  best  to  use.  In  some  instances  the  entire 
socket  can  be  made  with  an  ordinary  engine  bur,  while 
in  others  the  strongest  instruments  especially  designed  for 
implantation  are  none  too  strong.  In  some  instances  an 
instrument  which  clears  itself  well  during  one  operation 
clogs  annoyingly  during  another.  It  is  desiral:>le  to 
describe  at  this  point  the  various  useful  instruments 
which  have  been  designed  and  are  now  upon  the 
market.  While  all  of  them  are  not  necessary,  some 
one  or  more  of  each  class  are  indispensable.  The  tre- 
phines of  Dr.  Younger,  of  Paris,  which  have  been  im- 
proved by  Dr.  W.  W.  Walker,  of  New  York,  have  (as 
shown  in  Fig.  689)  a  set-screw  collar,  also  show^n  de- 
tached, which  slides  on  the  shank,  and  is  first  fixed  by 
a  set-screw  as  a  gauge  of  the  length  of  the  tooth  root. 
As  will  be  noticed,  the  trephines  cut  only  on  the  edge, 
and  hence  they  do  not  entirely  clear  themselves;  the  reamers  de- 
scribed on  a  succeeding  page  are  then  used  to  remove  the  core  and 
enlarge  the  socket. 


Instrument  for 
holding  flap  dur- 
ing theoperation. 


THE  OPERATION  OF  IMPLANTATION 


661 


The  spiral  knives  (Fig.  GIK))  devised  by  Dr.  W.  H.  Rollins,  of  Boston, 
are  in  many  cases  very  useful. 

They  are  also  open  to  the  objection  of  clogging.  As  an  improve- 
ment upon  these  the  spiral  crib  knife  shown  in  Fig.  691  has  the  advantage 
of  permitting  the  core  to  pass  within  it. 


Fig.  689 


Fig.  C90 


12      3      4      5 

Younger- Walker  trephines. 


1      2 

Rollins'  spiral  knives. 


Dr.  R.  Ottolengui,  of  New  York,  has  devised  a  set  of  reamers  (Fig. 
693).  There  are  nine  leaves  to  each  reamer  and  each  leaf  is  divided 
into  five  teeth.     Three  of  the  leaves  reach  the  apex  of  the  cone  point 


Fig.  691. 


Fig.  692 


Fig.  693 


1       2 

1             2 

Ottofy  spiral 

Two  forms  oi   Cryer's 

crib  knife. 

spiral  osteotome. 

12  3      4         5 

Ottolengui's  reamers. 


and  thus  allow  a  more  rapid  forward  drilling  into  the  bone.     A  sliding 
collar  forms  a  gauge  to  indicate  the  proper  depth  to  drill. 

The  reamers  designed  by  Dr.  Younger,  illustrated  in  Fig.  694,  are 
also  very  suitable  for  this  purpose.  Dr.  Cryer's  spiral  osteotome — 
two  forms  of  which  are  shown  in  Fig.  692,  one  with  dentate  edges,  the 


662 


PLANTATION  OF  TEETH 


other  without — is   an   achniiaMc   instrimiciit    for  forniiiiff   the  artificial 
socket. 

When  it  is  necessary  to  deepen  or  alter  the  shape  of  the  socket,  it  is 
done  very  simply  with  either  the  ordinary  hnrs  of  the  dental  engine 
or,  what  is  preferable,  a  bur  with  a  loniii;  shank  such  as  shown  in  the 
accompanying  illustration  (Fig.  695). 


Fici.  G94 


e    #   «? 


1       2       3 

Dr.  Younger's  re;vmers. 


( 


I-K..   (iO.-) 


'4\ 


12      3      4 

Ilnsine  burs  with  lone  shank. 


The  following  are  to  be  recommended:  Xos.  1  and  3  of  the  Walker- 
Younger  trephines,  Nos.  1  and  3  of  the  Younger  reamers,  Nos.  1  and 
2  of  the  Rollins  spiral  knives,  Nos.  1  and  2  of  the  Ottofy  spiral  crib 
knives,  and  Nos.  1,  3,  and  4  of  the  Ottolengui  reamers  and  Cryer's 
osteotome. 

During  the  progress  of  the  drilling  of  the  socket,  the  tooth  should 
be  frequently  inserted  until  a  proper  adjustment  has  been  secured. 
Occasionally  these  teeth  can  be  implanted  and  so  perfectly  fitted  that 
it  is  almost  impossible  to  remove  them  with  the  unaided  fingers;  while 
at  times  the  bone  is  so  cancellated  and  the  tissues  so  flabby  that  a  socket, 
no  matter  how  carefully  drilled,  will  not  retain  the  tooth  in  place.  Noth- 
ing is  gained  by  a  too  clo.se  adjustment  of  the  root,  as  pressure  must 
undoubtedly  be  exerted,  and  pressure  causes  resorption,  and  may  be 
followed  by  inflammation.  A  fair,  moderate  fitting  of  the  root  is  all 
that  should  be  aimed  at.  Just  before  the  final  adjustment  the  socket, 
gums,  tooth,  and  all  parts  contiguous  thereto  should  be  placed  in  an 
aseptic  condition  and  the  cap  adjusted  in  the  manner  before  described. 
Though  the  tooth  may  be  adjusted  to  its  socket  so  that  inmiediately 
afterward  it  exhibits  much  firmness,  yet  in  a  few  days  subsequent  to 
the  operation  it  invariably  shows  less  rigidity  and  an  apparent  tendency 
to  loosening.  This  result  is  probably  due  to  the  resorption  of  those 
areas  of  contact  between  the  tooth  and  its  artificially  formed  alveolus 
where  the  greatest  amount  of  pressin-e  is  exerted.     The  period  of  loosen- 


THE  OPERATION  OF  1 M I'LAXTATWN  663 

ino;  is  (Generally  (Hiickly  followed  l)y  a  proo-resslvely  iiicrea.sing  firmness 
aiul  iimnohility  of  tlie  tooth  caused  by  calcification  of  the  exudate 
thrown  out  by  the  walls  of  the  alveolus  in  the  process  of  repair  of  the 
surgical  injury  to  which  it  has  been  subjected  by  the  operation.  Planted 
teeth,  when  lost,  are  lost,  as  a  rule,  as  a  result  of  resorption  of  their 
roots.  The  process  seems  analogous  to  the  resorption  of  the  roots 
of  deciduous  teeth.  Present  records  seem  to  indicate  that  resorption 
of  the  roots  is  slowest  in  progress  in  replanted  teeth;  it  is  more  rapid 
in  transplanted  teeth,  and  most  rapid  in  implanted  teeth.  Intelligent 
observation  over  replantations  and  transplantations  extends  from 
twenty  to  forty  years.  The  observation  of  implanted  cases  extends  at 
this  writing  to  about  twenty-five  years,  and  successful  cases  have  been 
under  observation  which  have  remained  in  the  mouth  over  twelve 
years.  The  writer  has  the  records  of  cases  which  have  remained  and 
done  good  service  for  the  same  length  of  time. 


CHAPTEll    XX 

MANAGEMENT  OF  THE  DECIDUOIS  TEETH 

By  CLARK  L.  GODDARD,  A.M.,  D.D.S. 

Eruption. — Tlie  first  operation  the  dentist  is  called  npon  to  perform 
for  the  deciduous  (temporary)  teeth  is  lancintij  the  gums  as  an  aid  to 
eruption  of  those  organs.  This  is  not  necessary  in  normal  but  only 
in  pathological  cases.  Although  gum  tissue  in  its  normal  condition  is 
comparatively  insensitive,  when  it  is  inflamed  it  is  exceedingly  tender. 

The  principal  source  of  pain,  however,  is  not  in  the  tissue  overlying, 
but  when  a  tooth,  bound  down  by  the  dense  gum  tissue  above  it,  l)y  the 
growth  of  its  own  root  presses  upon  the  fc)rmati\'e  organ  below,  it  causes 
pain  which  in  many  cases  may  be  so  excessixe  as  to  cause  reflex  dis- 
orders of  alarming  character. 

Dr.  J.  W.  White^  says:  "The  manifestation  of  functional  inhar- 
mony  from  pathological  dentition  will  depend,  as  in  trouble  arising 
from  any  other  disturl)ing  cause,  upon  the  temperament  and  health 
of  the  child,  its  dietetic  management,  and  its  hygienic  surroundings. 
In  some  cases  there  is  a  gradual  development  of  biliary,  gastric,  enteric, 
and  cerebral  complications,  a  slow  but  steady  loss  of  vital  power,  with 
effort  at  recuperation  and  feeble  resistance  to  the  undermining  influ- 
ences which  gradually  but  surely  wear  out  the  young  life. 

"  In  other  cases  the  indications  of  disturbance  of  function  are  mani- 
fested primarily  in  the  nervous  system;  the  symptoms  are  all  charac- 
teristic of  acute  derangement  and  are  dangerous  from  their  violence 
and  uncontrollability.  High  fever,  vomiting,  choleraic  diarrhea,  men- 
ingitis, convulsions,  stupor,  anfl  death  are  the  ra])idly  succeeding 
phenomena.  Between  these  two  phases  there  is  exery  conceivable 
grade  of  symptoms,  every  imaginable  complication." 

By  many  it  has  been  urged,  as  an  objection  to  lancing  the  gums,  that, 
in  case  the  tooth  does  not  erupt  mmediately,  cicatricial  tissue  is  formed 
over  it  which  will  bind  the  tooth  down  more  rigidilv  than  before.  Cica- 
tricial tissue  is,  however,  of  a  lower  degree  of  organization  than  normal 
tissue,  and  is  more  easily  broken  down.  Furthermore  it  has  been  proved 
by  actual  test  that  teeth  erupt  more  readily  and  sooner  through  cicatri- 
cial gum  tissue  after  lancing  than  through  the  gum  ti.ssue  in  the  same 
mouth  over  corresponding  teeth  that  has  not  been  lanced. 

'  American  System  of  Dentistry,  vol.  iii,  j).  .'}27. 
(664) 


ERUPTION  AND  DURATION 


GG5 


Fk;.  696 


The  indications  for  interference  are  not  so  nnich  local  as  general — 
the  fretfulness,  inability  to  sleep,  and  other  symptoms  mentioned  by 
Dr.  White.  The  gum  tissue  over  the  erupting  tooth  may  or  may  not 
be  highly  inflamed,  but  the  absence  of  such  inflammation 
does  not  contraindicate  lancing.  In  fact  some  of  the 
gravest  systemic  disturbances  occur  when  no  local  mani- 
festations are  evident. 

The  object  is  to  divide  the  gum  tissue  which  binds 
down  the  tooth  and  to  allow  it  free  egress.  The  most 
suitable  instrument  is  shaped  like  that  shown  in  Fig. 
G9G,  and  sometimes  used  for  lancing  around  teeth 
before  extraction.  It  should  be  held  like  a  pencil  in 
writing,  so  that  one  or  more  fingers  can  form  a  rest  and 
guide. 

For  operating  on  the  lower  jaw  the  child  is  best  seated 
in  the  lap  of  the  operator  with  the  head  against  his  breast. 
•By  passing  the  left  arm  around  the  infant's  head  and  insert- 
ing ithe  left  thumb  in  its  mouth  with  the  fingers  under 
the  chin,  the  lower  jaw  can  be  held  rigidly  while  the  right 
hand  'performs  the  operation. 

For  operating  on  the  upper  jaw  it  is  best  to  lay  the 
child  upon  a  pillow  across  the  nurse's  lap.  The  operator 
takes  the  head  on  'or  between  his  knees,  opens  the  mouth 
by  inserting  one  or  more  fingers  of  the  left  hand,  and  holds 
the  thumb  and  forefinger  on  each  side  of  the  alveolar 
ridge,  thus  preventing  injury  to  contiguous  parts  during 
possible  stru.ggles  of  the  child. 

For  incisors  a  simple  longitudinal  incision  is  made,  a 
little  longer  than  the  cutting  edge  of  the  tooth.  The 
lancet  should  be  sharp,  so  as  to  easily  penetrate  to  the 
tooth.  No  harm  will  be  done  except  to  the  blade  of  the 
lancet.  For  the  canines  a  single  incision  is  good,  but  a 
crucial  incision  is  better.  Sometimes  lancing  is  necessary 
for  the  canine  after  it  is  partially  erupted,  as  the  gum 
tissue,  pierced  by  the  point  only  of  the  tooth,  may  form  a 
dense  ring  around  this  point  and  interfere  with  further 
eruption.  In  such  a  case  a  division  of  this  ring  in  two  or 
more  opposite  places  will  give  relief. 

For  the  molars  a  crucial  incision  is  best,  one  cut  extend- 
ing from  the  posterior  buccal  to  the  anterior  lingual  cusp, 
and  the  next  from  the  posterior  lingual  to  the  anterior 
buccal.  Sometimes  lancing  is  necessary  for  these  teeth 
after  partial  eruption.  After  the  cusps  have  pierced  the  gum,  the 
tooth  may  be  held  back  by  the  bands  of  tissue  in  the  sulci.  In  such 
cases  division  of  these  bands  in  the  same  direction  as  before  described 


Gum  lancet. 


cm 


MAXAGEMENT  OF   THE  DECIDVOIS   TEETH 


Fig.  697 


for   an    uiieruptcd    tooth   will    give    relief.       Sharj)-poiiitecl    curved 
scissors  are  well  adapted  to  this  latter  operation. 

Fig.  697  will  illustrate  the  direction  of  the  incisions  described.  The 
relief  afforded  is  generally  immediate.  In  one  case  a  child  who  had 
been  fretful  for  several  days,  and  who  had  not  slept  at  all  during  the 
day,  was  asleep  in  the  writer's  arms  within  five  minutes  after  the  opera- 
tion. The  gum  tissue  is  not  very 
sensitive,  so  the  operation  is  often 
painless.  The  little  sufferer  will 
often  recognize  the  relief  obtained 
4  and  point  to  other  portions  of  the 
gums  for  further  relief. 

Duration  of  the  Deciduous  Teeth. — 
The  importance  of  filling  cavities 
^b  in  the  children's  temporary  teeth 
is  often  overlooked,  even  by  den- 
tists themselves,  as  these  teeth  are 
supposed  to  be  lost  so  early  as  to 
render  such  operations  unnecessary. 
This  is  generally  true  with  the  in- 
cisors, is  less  true  with  the  canines, 
while  the  molars  often  need  attention.  Fig.  634  (see  Chapter  XVIII) 
shows  the  relations  of  the  deciduous  to  the  permanent  dentures  in  a 
child  of  about  six  years  of  age.  A  study  of  the  following  table  will 
show  that  while  the  incisors  are  Superseded  early  by  their  successors 
the  molars  are  in  place  nearly  twice  as  long: 


Lines  of  incision  in  lancing:  a,  a,  over  the 
molars;  6,  b,  over  the  canines  and  incisors 
before  eruption;  c,  c,  c,  over  the  molars 
and  canines  after  partial  eruption.  (J.  W. 
White.) 


Time  of  eruption.  I>oss. 

Central  incisors       ....  6  to    8  months.                 (ith  to     7th  year. 

Lateral 7  to    9  months.                  7th  to     8th  year. 

First  molars 14  to  16  months.                 9th  to  10th  year. 

(1  yr.  2  mo.  to  1  yr.  4  mo.) 

Canines 17  to  18  months,  f  Inf.      8th  to  10th  year. 

(l|  yrs.)  L  Sup.  11th  to  12th  year. 

Second  molars IS  to  24  months.                12th  to  1.3th  year. 

(1^  yrs.  to  2  yrs.) 


Duration. 
Sj  to  65  years. 
5  2  to  62  years. 
75  to  9    years. 


7  to  10  years. 
10  to  11  years. 


The  temporary  molars  should  be  preserved  for  three  reasons : 

1.  To  prevent  the  child  suffering  pain. 

2.  To  allow  proper  mastication  of  food. 

This  latter  is  of  extreme  importance,  as  these  years  are  especially 
important  ones  in  the  child's  growth.  If  he  is  prevented  by  pain  from 
properly  masticating  his  food  it  will  not  be  assimilated,  and  a  habit  of 
swallowing  food  without  masticating  may  be  continued  even  when  the 
permanent  teeth  have  erupted. 

3.  To  preserxe  the  fulness  of  the  arch  for  the  permanent  teeth  and 
assure  the  correct  positioning  of  the  first  permanent  molar,  upon  which 
depends  much  of  the  regularity  of  the  permanent  denture. 


THE  CHARACTER.  OF   THE  PAT  I  EXT 


007 


Early  loss  of  the  (kriduous  sceoiul  molar  will  allow  the  first  per- 
manent molar  to  m()\e  forward  and  occupy  room  that  should  be  pre- 
served for  the  i)reni()lars  (hieuspids).  Early  loss  of  the  first  temporary 
molar  will  allow  the  seeond  temporary  and  the  first  permanent  molar  to 
move  forward. 

The  crowns  of  the  temporarN-  molars  are  much  larger  than  the  necks, 
and  caries  of  the  proximal  surfaces  will  allow  them  to  crovv'd  together 
with  the  same  result.  Proximal  fillings  inserted  should  be  so  shaped  as 
to  preserve  the  original  contour.  If  the  first  permanent  molar  thus 
moves  forward  of  its  natural  position  a  smaller  arch  is  left  for  the  suc- 
cessional  teeth.  The  result  may  be  a  constricted  arch,  a  pointed  arch, 
upper  protrusion,  or  the  labial  displacement  of  the  canines. 


Fig.  6981 


}\ 


12 


Decalcification  of  the  deciduous  teeth.     The  numbers  indicate  years. 


THE  CHARACTER  OF  THE  PATIENT 

The  conditions  of  operating  on  the  deciduous  teeth  vary  so  much 
from  those  pertaining  to  the  permanent  teeth  that  a  different  consid- 
eration must  be  taken  of  filling  materials. 

The  little  patients'  mouths  are  small.  They  are  often  too  young  to 
reason  with  or  to  understand  the  purpose  of  the  operation.  They  have 
been  too  often  frightened  by  thoughtless  remarks  of  their  elders  in 
speaking  of  their  dentist. 

Oftentimes  the  first  sitting  must  be  utilized  merely  to  make  the 
acquaintance  of  the  child,  perhaps  cleaning  the  teeth  a  little,  or  intro- 
ducing some  palliative  dressing  in  an  aching  tooth.  The  greatest  care 
should  be  taken  not  to  hurt  the  child.  After  it  has  gained  a  little 
experience  it  recognizes  the  benefit  of  the  treatment,  and  wall  often 
submit  to  operations  that  older  patients  even  shrink  from. 

Odontalgia. — The  first  visits  by  children  are  usually  for  the  relief 
of  "toothache,"  and  may  occur  at  any  age  from  two  years  upward. 


^  Prof.  Pierce  in  American  System  of  Dentistry,  vol.  iii,  ]i.  639. 


668  MANAGEMENT  OF  THE  DECHJl'ors  TEETH 

The  first  treatment  of  most  children's  teeth  slionld  be  palhative. 
In  many  eases  a  fear  of  the  dentist  has  been  engendered,  w  hich  it  should 
be  the  prime  object  to  remove.  ]\lake  the  acquaintance  of  the  Httle 
patient  in  the  recej)tion  room,  talking?  perhaps  of  things  altogether 
foreign  to  the  case  in  hand,  and  distract  its  attention.  If  the  child  is 
very  timid,  examine  the  teeth  while  it  is  seated  in  an  ordinary  chair,  or 
in  its  parent's  laj),  and  apply  some  dressing  to  relieve  the  pain. 

In  the  operating  room  the  chair  should  be  adjusted  to  its  smallest 
size;  a  special  child's  seat  may  be  used,  or  a  cushion  half  the  size  of  the 
chair  seat,  and  not  too  soft.  The  child's  head  should  be  made  comfort- 
able in  the  head-rest.  The  operator  should  not  let  the  child  detect  him 
in  an  endeavor  to  hide  instruments;  the  necessary  ones  may  be  shown 
to  him  if  they  arouse  his  curiosity,  and  their  purpose  exj)lained. 

On  account  of  the  difficulty  the  child  has  in  making  himself  under- 
stood, or  from  his  not  knowing  what  he  wishes  to  describe,  diagnosis  is 
difficult.  A  child  cannot  always  distinguish  just  Mhere  pain  is  felt,  nor 
always  remember  its  exact  location.  In  most  cases  the  first  occurrence 
of  pain  is  during  mastication. 

It  is  necessary  to  ascertain  whether  pain  is  caused  by  an  erui)ting 
tooth,  a  nearly  exposed  pulp,  a  pulp  inflamed  and  dying,  a  putrescent 
pulp,  or  an  alveolar  abscess.  If  the  nearly  exposed  pulp  is  suspected, 
test  it  by  the  application  of  a  drop  of  cold  w^ater.  Pain  during  masti- 
cation may  be  caused  by  thermal  changes,  by  pressure  of  food  in  the 
cavity,  or  by  pressure  on  a  tooth  whose  pericementum  is  inflamed. 

If  the  tooth  is  aching  while  the  child  is  in  the  chair,  syringe  out  the 
cavity  with  warm  water,  dry  it  with  bibulous  paper,  and  apply  a  pledget 
of  cotton  saturated  with  oil  of  cloves,  campho-phenique,  or  whatever 
has  been  found  effective  with  permanent  teeth.  Fletcher's  carbolized 
resin  1  has  been  invaluable  for  this  purpose  in  the  writer's  practice. 
Applied  on  a  pellet  of  cotton  it  acts  as  an  anodyne,  and  the  resin 
hardens  in  the  cotton,  forming  with  it  a  temporary  stopping  which  will 
even  bear  the  force  of  mastication  for  a  few  days.  It  is  sometimes 
best  to  renew  this  dressing  a  few  times  before  attempting  a  more  per- 
manent treatment  or  filling. 

If  the  child  cannot  be  brought  to  the  office  again  within  a  few  days, 
let  the  parent  provide  himself  with  a  bottle  of  the  carbolized  resin  and 
an  inexpensive  pair  of  dressing  pliers.  Instruct  the  patient  how  to 
apply  the  cotton  dressing.  This  is  the  best  domestic  remedy  for  odon- 
talgia. Other  medicaments  may  be  used  by  the  parent,  such  as  oil  of 
cloves,  campho-phenique,  etc.,  but  their  eflPect  is  much  more  temporary. 
A  more  durable  dressing  may  be  made  by  mixing  zinc  oxid  and  car- 
bolized resin  to  the  consistence  of  putty  and  applying  it  in  the  cavity 

'  Carbolic  acid, 

Resin  (colophony) aa     51 

Chloroform fSss 


TREATMENT  WITH  til LV Eli  NITRATE  669 

previously  dried.  It  Iiardeiis  under  moisture,  and  makes  a  stopping 
that  will  remain,  in  some  eases,  for  several  weeks. 

During:  sueli  ])alliative  treatment,  sometimes  unavoidaLly  extended 
over  se\-eral  weeks  or  even  months,  the  ehild  is  growing  older,  is  gain- 
ing experience,  is  becoming  used  to  manipulation,  begins  to  recognize 
the  l)enefit  of  treatment  of  the  teeth — in  a  word,  is  being  trained  or 
educated  for  a  good  patient  for  whom  more  permanent  operations  may 
be  attempted. 

Prof.  L.  L.  Dunbar  says:  "As  a  domestic  palliative  always  at 
hand,  in  the  treatment  of  pulp  exposure  and  restricting  odiMitalgia,  use 
ammonia  on  cotton;  its  repeated  use  will  devitalize  the  pulp,  at  the 
same  time  effecting  its  removal  by  saponification." 


TREATMENT   WITH    SILVER   NITRATE 

More  than  forty  years  ago  the  application  of  silver  nitrate  for  arrest- 
ing decay  was  advocated,  but  for  many  years  no  notice  was  taken 
of  it.  Within  the  last  five  years  it  has  been  advocated  again,  especially 
for  use  in  the  temporary  teeth.  The  fact  that  it  blackens  the  decayed 
surface  is  not  as  objectionable  as  with  permanent  teeth.  Dr.  Stebbins^ 
advocated  the  use  of  a  solution  of  the  crystals  of  silver  nitrate  in  cari- 
ous cavities  in  temporary  teeth.  He  applies  it  by  means  of  a  small 
stick  inserted  in  a  socket  instrument  as  shown  in  Fig.  699.     JNIany 

Fig.  699 


cases  will  need  no  further  treatment,  decay  being  completely  arrested. 
Some  cases  will  need  secondary  treatment  after  a  few  months.  In 
many  cases  he  advises  filling  the  cavity  with  gutta-percha  after  the 
application. 

Dr.  C.  N.  Peirce-  advises  saturating  pieces  of  blotting  paper  with  40 
per  cent,  solution  of  silver  nitrate,  and  keeping  these  on  hand  for 
use. 

Dr.  E.  C.  Kirk  advises  the  use  of  asbestos  felt  for  saturation  with 
the  solution  in  preference  to  blotting  paper  or  cotton.  He  says:^  "  The 
contact  of  silver  nitrate  with  vegetable  fiber  'of  any  sort  involves  not 
only  a  destruction  of  the  fiber,  but  also  of  the  silver  nitrate,  so  that  the 

1  International  Dental  Journal,  1891,  p.  661.  ^  Ibid.,  1893,  p.  152. 

3  Dental  Cosmos,  1893,  p.  667. 


G70  MAXAdEMEXT  OF  THE  DECIDUOUS  TEETH 

preparation  in  a  short  time  loses  its  desirable  qualities."  He  advises 
that  the  asbestos  felt  be  heated  before  the  blowpipe  before  saturation, 
to  burn  out  any  organic  material  which  may  be  present. 

Dr.  A.  M.  Holmes^  advises  its  use  as  follows  for  proximal  cavities: 
"Cut  away  the  walls  to  a  V  shape,  and  with  a  piece  of  gutta-percha, 
softened  by  heat,  of  the  proper  size  to  fill  tlie  space,  bring  the  surface 
to  come  in  contact  with  the  diseased  part  of  the  teeth,  into  contact  with 
the  powdered  crystals  of  silver  nitrate  and  carry  it  to  the  place  in  the 
tooth  or  teeth  prepared  for  its  reception,  x^t^cking  it  firmly  and  leaving 
it  there  to  be  worn  away  by  use  in  mastication.  When  that  takes  place 
the  surfaces  of  the  teeth  treated  will  be  found  black  and  hard,  with 
no  sensitiveness  to  the  touch  or  to  change  of  temperature,  and  they 
will  remain  so  indefinitely.  In  case  the  child  is  so  timid  as  to  prevent 
this  course,  dry  the  cavity,  take  out  as  much  softened  dentin  as  the 
patient  will  permit,  carry  the  crystals  on  softened  gutta-percha  into 
the  cavity  and  pack  it,  leaving  it  until  such  time  as  desirable  to  make 
a  more  thorough  operation." 

In  the  writer's  opinion  it  is  better  to  open  proximal  cavities  from 
the  occlusal  surface  rather  than  make  V-shaped  spaces,  as  the  full 
diameter  of  the  teeth  should  be  left  to  preserve  the  fulness  of  the  arch. 

Silver  nitrate  in  its  action  penetrates  but  a  short  distance. 


FILLING  MATERIALS 

Gutta-percha. — Pink  base-plate  gutta-percha  is  a  most  valuable 
filling  material.  In  proximal  cavities  where  it  is  not  exposed  to  wear 
and  where  the  shape  of  the  cavity  is  such  as  to  retain  it,  it  is  prac- 
tically indestructible.  In  occlusal  and  compound  cavities  in  which  it 
is  exposed  to  wear  it  has  wonderful  durability,  lasting  in  some  cases 
for  several  years. 

Directions  for  Use. — Cut  the  gutta-percha  in  small  pieces  and  place 
them  on  a  gutta-percha  warmer,  where  they  can  be  kept  soft  but  not 
heated  enough  to  injure  the  material.  The  instruments  also  should 
be  warmed. 

Occlusal  Cavities. — Cut  away  the  margins  of  thin  enamel  with 
suitably  shaped  chisels,  and  remove  the  decayed  and  softened  dentin 
with  spoon  and  hatchet  excavators.  Do  this  as  thoroughly  as  the 
patient  will  permit,  but  do  not  sacrifice  the  patient  to  thoroughness,  for 
the  thorough  removal  of  softened  dentin  is  not  as  essential  with  the 
deciduous  as  with  permanent  teeth,  because  the  gutta-percha  is,  by 
mastication,  kept  in  such  accurate  contact  with  all  the  walls  of  the 
cavity  that  further  softening  will  go  on  very  slowly  if  at  all.    No  special 

1  Dental  Cosmos,  1892,  j).  982. 


FILLING  MATERIALS  671 

attention  need  })e  ])ai(l  to  the  form  of  the  cavity,  except  that  its  moutii 
should  not  be  larger  than  the  interior,  nor  should  any  parts  of  the  cavity 
be  inaccessible  to  the  filling  material.  After  excavating,  dry  the  cavity 
with  bibulous  paper,  and  apply  campho-phenique,  oil  of  cloves,  or 
carbolic  acid,  to  sterilize  any  softened  dentin  which  may  not  have  been 
removed.  For  drying  ca^'ities,  prepare  paper  cylinders,  of  different 
sizes,  as  follows :  Tear  the  bibulous  paper  in  strips  from  half  an  inch  to 
two  inches  in  width.  Roll  or  twist  each  of  these  strips  into  a  rope, 
but  not  too  tightly — just  enough  to  retain  the  shape.  Cut  these  ropes 
into  cylinders  from  a  quarter  to  half  an  inch  in  length.  Some  of  these 
will  be  as  large  around  as  a  lead  pencil  and  others  no  larger  than  the 
lead  itself. 

Protect  the  tooth  from  moisture  as  well  as  possible.  For  lower 
cavities  fold  a  small  napkin  diagonally  from  the  corner  until  it  is  about 
half  an  inch  wdde.  Put  the  end  of  this  between  the  gum  of  the  upper 
canine  and  the  lip  and  extend  the  napkin  back  between  the  upper 
molars  and  the  cheek  beyond  the  last  tooth,  then  down  behind  the  last 
lower  molar,  and  press  it  between  the  lower  teeth  and  tongue.  Tell 
the  patient  to  raise  the  tongue  as  it  is  applied,  then  to  lower  the  tongue 
and  hold  the  napkin  with  it.  The  part  of  the  napkin  between  the  upper 
teeth  and  the  cheek  will  cover  the  mouth  of  the  duct  of  Steno,  and 
prevent  or  absorb  the  flow  of  saliva.  It  is  better  to  cover  the  mouth 
of  this  duct  with  a  piece  of  spunk  about  half  an  inch  in  diameter  before 
applying  the  napkin.  The  folds  of  napkin  between  the  lower  teeth  and 
tongue  and  under  the  tongue  will  absorb  the  saliva  from  the  sub- 
maxillary glands.  This  part  of  the  napkin  can  be  held  in  place  with 
a  mouth  mirror  or  other  blunt  instrument,  by  the  operator  or  assis- 
tant. After  applying  the  napkin  use  a  large  bibulous  paper  cylinder 
to  absorb  the  moisture  from  the  tooth  to  be  filled  and  also  from  con- 
tiguous ones.  With  smaller  cylinders  or  pellets  dry  the  cavity.  Apply 
once  more  campho-phenique  or  other  medicament,  and  absorb  the 
excess. 

The  gutta-percha  having  been  meanwhile  warmed  and  softened, 
pick  up  a  small  piece  of  it  with  a  cold  round-pointed  instrument  and 
press  it  into  the  cavity.  If  the  cavity  is  not  large,  a  single  piece  of 
gutta-percha  of  a  diameter  less  than  that  of  the  cavity,  but  longer 
than  the  cavity  is  deep,  can  be  pressed  in  quickly  and  at  one  move- 
ment. For  medium-sized  cavities  select  a  piece  of  gutta-percha  large 
enough  to  cover  the  floor  of  the  cavity  and  press  it  into  place  with 
a  cold  instrument,  as  a  warm  instrument  might  drag  it  from  its  place. 
Add  similar  pieces,  pressing  each  one  to  the  place  in  which  it  is  to 
remain,  until  the  cavity  is  full.  If  at  any  time  the  gutta-percha  in  the 
cavity  becomes  so  hard  as  to  lose  its  plasticity,  apply  a  warm  instru- 
ment to  soften  the  surface,  so  that  the  next  piece  will  adhere  to  the  others. 
As  the  filling  nears  completion  select  a  small  piece  for  the  last,  just 


C72  MAXAdEMENT  OF   THE   DECIDUOCS   TEETH 

large  eiiough  to  (•()ini)l('tc  the  fillin<ij  jiiul  no  iiioiv,  so  tli;it  none  will 
have  to  be  trimnicd  away,  for  in  triinniinj^  tlie  siiri)Ius  away  the  lilliiig 
may  be  drawn  from  contact  with  the  walls  of  the  cavity. 

In  fillinfi^  lar<j;e  cavities  it  may  be  necessary  to  hold  the  first  ])iece  in 
position  with  anotlier  instrument  nntil  sufficient  material  is  added  for 
self-retention.  At  the  completion  of  tlie  filling  slight  pressure  with  a 
Marm  instriuncnt  should  be  made  in  such  a  manner  as  to  force  the 
material  against  all  the  margins  of  the  cavity. 

Proximal  Cavities. — Where  possible,  proximal  cavities  should  be 
opened  from  the  buccal  surfaces,  as  advised  by  Dr.  l^onwill,  as  in 
such  cases  gutta-percha  fillings  will  not  be  exposed  to  the  force  of 
mastication.  This  plan  is  not  often  practicable  because  the  patient 
is  seldom  presented  till  the  ca\'ity  has  become  visible  by  opening 
into  the  occlusal  surface  of  the  tooth.  In  such  cases  cut  away  the 
enamel  only  enough  to  give  access  to  the  cavity,  excavate  the  decayed 
dentin,  and  trim  the  buccal,  lingual,  and  cervical  walls  until  a  smooth, 
firm  margin  is  obtained. 

In  filling  such  a  cavity  use  small  pieces  of  softened  gutta-percha, 
pressing  each  piece  where  it  is  to  "remain,  and  avoid  a  surplus.  Press 
the  gutta-percha  against  the  adjoining  tooth  as  if  it  were  a  matrix  or  a 
fourth  wall  of  the  cavity  and  let  it  remain.  It  is  useless  to  trim  it 
away  from  the  adjoining  tooth,  because  the  force  of  mastication  would 
soon  spread  the  filling  against  it  again. 

If  a  proximal  cavity  cannot  be  readily  shaped  so  that  it  will  retain 
the  gutta-percha,  it  may  be  packed  against  the  adjoining  tooth,  as 
if  it  were  an  occlusal  cavity.  It  will  prevent  decay,  esjjecially  if  silver 
nitrate  is  applied,  as  already  described,  and  may  be  retained  until  the 
patient  is  older,  when  a  more  thorough  operation  may  be  performed. 

The  spreading  of  the  gutta-percha  by  the  force  of  mastication  will 
tend  to  separate  the  teeth^ — which  is  sometimes  an  advantage;  and  also 
to  press  ui)on  the  gum  in  the  interj)roximal  space — which  is  a  disad- 
vantage. In  filling  children's  teeth  we  cannot  always  reach  the  ideal, 
but  must  select  the  method  and  material  which  will  have  the  greatest 
advantage  with  the  least  disadvantage.  If  the  teeth  separate  so  much 
that  the  pressure  of  the  gutta-percha  upon  the  gum  tissue  becomes  a 
serious  annoyance,  some  other  material  must  be  substituted. 

To  prevent  the  impinging  of  the  gutta-])ercha  upon  the  gum  in  the 
interproximal  space.  Dr.  ]\I.  W.  Hollingsworth^  has  invented  a  space 
guard,  consisting  of  a  concave  elliptical  piece  of  metal  coated  on  the 
convex  surface  with  gutta-percha.  This  guard  is  to  bridge  over  the 
interproximal  space.  It  is  placed  in  position  with  the  instrument 
shown  in  h.  Fig.  700,  which  is  warmed  slightly,  so  that  the  point  can 
enter  a  small  hole  in  the  guard  and  adhere  to  the  gutta-percha  on  the 

■  Dental  Cosmos,  189G,  vol.  xxxviii,  p.  553. 


FILLINd  MA  TE RIALS 


67:: 


under  side,  as  shown  at  c.  The  guard  is  i)la('e(l  in  the  cavities,  after 
warming  the  gutta-percha,  as  shown  in  Fig.  701,  and  thus  covers  the 
cervical  borders.  Gutta-percha  is  now  filled  in  over  the  guard  as  if 
the  two  cavities  formed  a  single  crown  cavity. 


Fu;.  700 


Fig.  701 


Advantages  of  Gutta-percha. — It  is  easily  applied  to  the  cavity;  it  is 
insoluble;  is  durable  even  w4ien  masticated  upon;  is  a  non-conductor  of 
thermal  impulses;  the  filhng  is  finished  as  soon  as  the  cavity  is  full;  it 
spreads  under  the  force  of  mastication,  and  is  thus  kept  in  contact  with 
the  walls  of  a  cavity;  it  can  be  used  even  under  moisture. 

Disadvantages. — Gutta-percha  is  softer  than  other  filling  materials, 
and  hence  wears  away  more  rapidly.  In  proximal  cavities  it  will 
spread  the  teeth  apart,  and  may  then  press  upon  and  irritate  the  gum. 

Dryness  of  the  cavity,  though  very  desirable,  is  not  absolutely 
necessary. 

Advantage  of  Zinc  Phosphate  Cement. — It  is  a  poor  conductor  of 
heat;  it  withstands  the  force  of  mastication  better  than  gutta-percha; 
it  adheres  to  the  walls  of  the  cavity,  and  hence  will  remain  where  no 
other  material  can;  it  is  easily  applied;  its  color  may  be  selected  to 
match  the  tooth. 

Ames'  copper  cement  seems  to  be  even  a  better  preservative  than  zinc 
cements  in  places  where  the  black  color  is  not  objectionable. 

Disadvantages. — Absolute  dryness  of  the  cavity  is  a  prerequisite  to 
its  success;  it  must  be  kept  dry  for  several  minutes  after  it  is  inserted 
in  the  cavity.  Zinc  phosphate  cement  disintegrates  in  some  mouths 
much  more  rapidly  than  in  others.  If  placed  too  near  the  pulp  it  may 
by  chemical  irritation  devitalize  it. 

Application  of  the  Rubber  Dam. — While  many  hesitate  to  attempt 
the  use  of  the  rubber  dam  with  children,  it  will  be  found  upon  trial  that 
most  of  them  will  submit  to  it  without  trouble,  and  many  will  prefer  it 
to  other  means  of  keeping  cavities  dry. 
43 


67i  MAXAGEMEXT  OF  THE  DECIDUOUS   TEETH 

Although  there  is  an  advantage  in  applying  the  rubber  dam  before 
excavating — because  dryness  makes  the  teeth  less  sensiti\e,  and  a  clearer 
view  of  the  cavity  is  obtained — still,  for  the  sake  of  not  tiring  the  little 
patients  by  too  long  restraint  in  one  position,  it  is  better  to  do  most  of 
the  excavating  before  its  application. 

The  small  size  of  the  necks  of  the  deciduous  teeth  compared  with 
that  of  the  crowns  renders  the  retention  of  the  rubber  dam  easier  than 
with  permanent  teeth.  Even  considering  the  smallness  of  the  patients' 
mouths,  the  application  of  the  rubber  dam  is  not  difficult  in  many 
cases. 

For  retaining  the  rubber  dam  on  the  second  molar  a  clamp  will 
sometimes  be  necessary,  but  for  the  other  deciduous  teeth  a  floss  silk 
ligature  will  be  sufficient.  Having  punched  holes  of  suitable  size 
through  the  rubber  dam,  apply  it  over  the  teeth  affected.  If  the  cavity 
is  in  the  occlusal  or  buccal  surface  only,  it  will  not  be  necessary  to 
apply  it  over  more  than  one  tooth;  but  if  the  cavity  is  in  the  proximal 
surface  it  will  be  necessary  to  apply  the  rubl)er  dam  over  two  or  some- 
times three  teeth,  or  even  more,  if  several  ca^'ities  are  to  be  filled  at 
one  sitting. 

It  is  not  always  necessary  to  tie  a  ligature  around  the  neck  of  the 
tooth,  as  merely  passing  the  waxed  floss  silk  between  the  teeth  will 
often  force  the  rubber  around  the  neck  of  the  tooth  enough  to  retain  it 
even  above  a  proximal  cavity.  The  silk  may  then  be  removed  by 
drawing  the  end  through  between  the  teeth. 

With  a  thin  burnisher  or  spatula  turn  up  the  edge  of  the  rubber 
around  the  neck  of  the  tooth  toward  the  gum.  The  tendency  of  the 
rubber  then  will  be  to  slide  in  that  direction  and  not  over  the  crown. 
If  a  ligature  be  necessary  to  hold  the  rubber  above  the  edge  of  a  proximal 
cavity  tie  it  tightly  around  the  neck  of  the  tooth,  e^•en  forcing  it  toward 
or  under  the  edge  of  the  gum  with  an  instrument  when  necessary. 
The  clamp  on  a  second  molar  may  often  be  dispensed  with  after  a 
ligature  is  applied,  unless  it  is  needed  to  hold  the  rubber  out  of  the 
operator's  way.  The  only  object  in  omitting  the  clamp  is  to  prevent 
pain  or  discomfort  to  the  child. 

If  a  simple  ligature  will  not  retain  the  rubber  on  a  second  molar 
before  the  first  permanent  molar  has  appeared,  its  efficiency  may  be 
greatly  increased  by  stringing  a  bead,  about  an  eighth  of  an  inch  or  less 
in  diameter,  on  the  thread  and  tying  a  simple  knot  in  it  so  that  the 
bead  will  be  in  about  the  middle  of  the  ligature.  Tie  the  ligature  around 
the  tooth  so  that  the  bead  will  lie  against  the  distal  surface  of  the 
second  molar  on  or  near  the  gum.  This  bead  will  prevent  the  rubber 
slipping  off  the  tooth.  A  short  cylinder  of  bibulous  paper  may  be  tied 
in  the  ligature  and  applied  with  the  same  effect,  and  even  a  large  knot 
in  the  ligature  on  the  distal  surface  of  the  tooth  will  often  answer  the 
purpose. 


FILLING  MATERIALS  675 

The  corners  of  the  rubber  dam  should  be  held  out  of  the  way  by  a 
suitable  holder  extending  around  the  head.  The  lower  border  may  be 
held  out  of  the  operator's  way  by  small  weights,  hooked  in  the  edge. 

Dry  the  cavity  and  the  whole  tooth  or  teeth,  and  complete  the 
excavation. 

Filling  Cavities  and  Cement. — As  cement  can  be  applied  easily 
in  undercuts  and  very  irregularly  shaped  cavities  it  is  not  necessary  to 
cut  away  the  enamel  more  than  is  sufficient  to  enable  the  operator  to 
remove  the  disintegrated  dentin  thoroughly.  Even  the  thorough  re- 
moval of  the  latter  is  not  as  essential  for  a  cement  filling  as  for  other 
materials,  for,  if  the  edge  of  the  cavity  can  be  made  smooth  and  the 
softened  dentin  be  thoroughly  sterilized,  the  cement  will  hermetically 
seal  it  and  prevent  further  disintegration  until  it  is  worn  away  beyond 
the  sound  edges. 

It  must  be  remembered  in  excavating  cavities  in  deciduous  teeth 
that  the  pulp  is  much  larger  in  proportion  to  the  size  of  the  crown  than 
in  permanent  teeth,  and  that  in  trying  to  make  undercuts  or  retaining 
grooves  deep  enough  to  retain  a  filling,  the  pulp  may  be  exposed — an 
accident  which  should  be  carefully  guarded  against,  for  the  deciduous 
pulp  has  not  the  recuperative  power  possessed  by  the  pulp  of  a  perma- 
nent tooth.  Moreover,  death  of  the  pulp  prevents  normal  resorp- 
tion of  the  root,  and  may  thus  cause  irregularity  of  the  permanent 
teeth. 

For  most  cases  the  cement  should  be  mixed  as  thick  as  can  be  easily 
and  quickly  manipulated,  but  if  the  pulp  is  nearly  exposed  the  cement 
should  be  used  so  thin  that  it  can  be  applied  without  pressure,  by 
flowing  it  over  the  floor  of  the  cavity.  Cement  mixed  moderately  thin 
will  adhere  better  to  the  walls  of  the  cavity  than  when  it  is  as  thick 
as  it  is  possible  to  apply  it.  The  thinner  the  cement  the  longer  time 
it  will  take  to  harden,  but  the  thicker  it  is  mixed  the  more  durable  it 
will  be.  Do  not  keep  the  little  patient  in  a  constrained  position  longer 
than  necessary.  The  easier  the  first  operation  is  for  him  the  more 
readily  will  he  return  for  the  second. 

If  the  pulp  is  very  nearly  exposed  apply  Fletcher's  carbolized  resin 
over  the  floor  of  the  cavity.  For  this  purpose  remove  the  stopper  of 
the  bottle  until  by  evaporation  the  carbolized  resin  has  thickened  to  the 
consistence  of  syrup.  Dip  a  small  probe  in  the  thickened  mass,  so 
that  a  small  drop  will  adhere  to  the  end.  This  drop  may  be  then  con- 
veyed to  and  spread  over  the  floor  of  the  cavity.  This  will  prevent 
contact  of  the  cement  with  the  most  sensitive  dentin  and  lessen  the 
possibility  of  deleterious  action  on  the  pulp. 

Where  it  is  possible  to  apply  the  rubber  dam  and  to  excavate  thor- 
oughly the  same  excellent  result  with  cement  may  be  expected  as  when 
it  is  used  in  permanent  teeth,  but  often  it  is  not  possible  to  operate  as 
thoroughly. 


676  MANAGEMENT  OF  THE  DECIDUOVS  TEETH 

By  applying  virlfed  paraffin^  or  sandardc  vdniish  to  the  cement  the 
rubber  dam  may  be  removed  sooner  than  otherwise,  and  the  cement 
will  be  protected  from  moisture  by  the  coating  of  paraffin  or  varnish. 

As  paraffin  is  insohible  in  any  agent  that  can  attack  it  in  the  mouth, 
the  more  it  is  absorbed  by  tlie  cement  the  longer  it  will  protect  it  from 
everything  but  wear;  therefore,  do  not  l)e  content  merely  to  flow  the 
melted  paraffin  over  the  cement,  but  hold  a  heated  instrument  in  con- 
tact with  the  filling  and  keep  the  paraffin  melted  until  all  that  is  possible 
is  absorbed.  If  a  proximal  filling  has  been  inserted  pass  a  very  thin 
heated  spatula  between  the  cement  filling  and  the  adjoining  tooth  to 
make  sure  that  the  paraffin  covers  it  to  its  cervical  margin. 

When  the  rubber  dam  cannot  be  applied,  cement  may  still  be  used 
with  success  if  the  ca\ity  can  be  kept  dry  with  napkins  or  rolls  of  cotton 
or  spunk  until  it  is  inserted  and  quickly  covered  with  melted  paraffin. 

Deep  cavities  may  be  advantageously  lined  with  cement  and  pro- 
tected with  paraffin  until  the  cement  is  hard,  when  the  paraffin  may  be 
removed  and  gutta-percha  or  amalgam  inserted. 

Occlusal  fillings  of  cement  can  be  kept  dry  by  applying  temporary 
stopping  very  soft  as  soon  as  the  cement  is  put  in.  Gilbert's  is  excel- 
lent for  the  purpose,  as  it  adheres  to  the  cement.  Buccal  fillings,  some- 
times approximal,  may  be  protected  in  the  same  way.  A  thin  tempo- 
rary stopping  may  be  left  to  be  worn  away  by  occluding  teeth. 

Cavities  in  Incisoks. — Decay  in  deciduous  incisors  is  much  more 
rare  than  in  the  other  teeth,  and  they  are  lost  so  early  in  child  life  that 
it  is  seldom  necessary  to  fill  them.  Zinc  phosphate  cement  is  the  best 
filling  material  for  these  teeth,  because  they  are  so  small  that  it  is  very 
difficult  to  shape  the  cavities  properly  for  retaining  other  materials. 

If  it  is  found  that  cement  disintegrates  rapidly  in  proximal  cavities, 
an  attempt  should  be  made  to  shape  them  so  as  to  retain  gutta-percha. 
The  first  filling  of  cement  may  have  removed  the  sensitiveness  suffi- 
ciently to  allow  deeper  excavating  at  a  subsequent  sitting,  or  there 
may  have  been  a  deposit  of  secondary  dentin,  thus  removing  the  pulp 
from  danger  of  exposure  in  properly  shaping  the  cavity. 

Amalgam. — While  amalgam  is  a  valuable  filling  material,  its  use 
necessitates  much  greater  care  in  the  preparation  of  cavities  than  is 
necessary  with  gutta-percha  or  cement,  for  it  neither  spreads  under 
mastication  like  the  former  nor  does  it  adhere  to  the  walls  of  a  cavity 
like  the  latter.  The  spreading  of  gutta-percha  will  stop  a  leak  that 
would  be  fatal  to  an  amalgam  filling,  and  cement  will  adhere  in  a  cavity 
from  which  amalgam  would  be  easily  dislodged. 

Amalgam  should  be  used  when  the  decay  can  be  thoroughly  exca- 
vated and  the  cavity  prepared  with  strong,  smooth  edges,  and  good, 
retaining  form.     As  amalgam  is  a  better  conductor  of  thermal  im- 

'  Dr.  Bonwill's  suggestion. 


FILLIXG  MATERIALS  677 

pulses  than  either  of  the  materials  before  mentioned,  it  will  not  be 
tolerated  so  near  the  pulp,  hence  deep  caxities  must  be  Uned  with  either 
gutta-percha  or  zinc  phosphate. 

The  large  size  of  the  pulp  of  deciduous  teeth — greater  in  proportion 
than  that  of  the  permanent  teeth — must  not  be  forgotten  in  exca- 
vating, and  often  it  is  impossible  to  make  suitable  retaining  grooves 
for  amalgam  without  cutting  dangerously  near  the  pulp,  especially  in 
proximal  cavities. 

The  preparation  of  occlusal  cavities  is  comparatively  simple,  as  the 
enamel  may  be  easily  cut  away  so  as  to  make  firm  edges,  slightly 
bevelled,  and  to  allow  thorough  excavation  of  softened  dentin. 

The  burring  engine  can  be  used  to  greater  advantage  with  children 
than  many  would  suppose.  The  whirring  noise  often  distracts  their 
attention  from  a  slight  pain  they  might  otherwise  notice,  and  the  assur- 
ance that  the  work  can  be  done  more  quickly  is  a  great  encouragement. 

In  preparing  proximal  cavities  for  amalgam  a  free  opening  should 
be  made  in  the  occlusal  surface  and  given  a  dovetail  shape,  extending 
farther  upon  the  occlusal  surface  in  proportion  to  the  size  of  the  cavity 
than  in  permanent  teeth,  because  more  reliance  must  be  placed  on  it  for 
retention  than  upon  lateral  grooves,  for  there  is  not  much  depth  of 
dentin  in  which  to  make  them.  The  cervical  border  of  the  cavity  must 
be  smooth  and  the  floor  at  right  angles  to  the  long  axis  of  the  tooth. 
The  lateral  walls  must  be  cut  smooth  and  bevelled,  and  may  be  slightly 
grooved.     If  the  cavity  extend  below  the  margin 

Fig   70*^ 

of  the  gum,  the  latter  should  be  crowded  away 
with  a  temporary  stopping  or  by  packing  a  tightly 
rolled  pledget  of  cotton  between  the  teeth  and 
relying  on  its  swelling. 

In  many  cases  it  is  possible  to  extend  a  proxi- 
mal cavitv  to  the  sulcus  and  make  a  step  anchorage,       „        .,     ■     ^    . 

^  "  J.  o    '  Prepared  cavity  showing 

as  in  permanent  teeth.  bevelling  of  enamel  edges. 

While  the  apphcation  of  a  rubber  dam  is  not  as     t;:^'  ^°f  "^"'^'^  ^^'^  ^°' 

.  .  .     .  filling,  B. 

essential  as  m  using  cement,  it  is  a  great  advantage, 
for  it  renders  the  proper  preparation  of  the  cavity  more  certain,  but  it 
need  not  be  applied  until  the  cavity  is  nearly  prepared.    Its  use  is  more 
often  necessary  with  the  lower  teeth  than  with  the  upper. 

Amalgam  should  not  be  mixed  too  dry,  but  should  be  plastic  enough 
to  be  packed  easily  without  crumbling.  In  occlusal  cavities  introduce  a 
piece  half  as  large  as  the  cavity,  and  with  a  small  ball  burnisher  spread 
it  over  the  floor  of  the  cavity  toward  the  walls.  Introduce  other  smaller 
pieces  and  proceed  as  before  until  the  cavity  is  nearly  full.  Excess  of 
mercury  is  thus  forced  to  the  edges  of  the  ca\'ity,  whence  it  can  be 
brushed  away  with  cotton  or  bibulous  paper. 

The  last  pieces  of  amalgam  should  be  "wafered,"  as  recommended 
by  Prof.  J.  Foster  Flagg — that  is,  squeezed  in  chamois  skin  with  large 


678  MANAGEMENT  OF  THE  DECIDIOIS  TEETH 

flat-iiowd  pliers  until  as  imicli  mercury  as  possible  is  pressed  out.  This 
leaves  the  amalgam  in  a  thin,  brittle  wafer,  too  hard  for  ordinary 
use.  Break  it  up  in  pieces  half  the  diameter  of  the  cavity.  Press  one 
of  these  in  the  middle  of  the  nearly  comi)leted  filling.  It  will  readily 
absorb  the  excess  of  mercury  that  has  been  worked  to  the  surface, 
and  can  be  spread  toward  the  margins  with  a  round  burnisher.  Other 
pieces  can  be  burnished  on  until  the  filling  is  (luite  hard. 

In  filling  proximal  cavities  the  same  plan  may  be  followed  if  a  matrix 
of  thin  steel  or  German  silver  be  used.  In  lieu  of  the  matrix  a  very 
thin  s])atula  may  be  held  between  the  teeth. 

Whenever  possible,  fillings  in  deciduous  molars  should  be  gi\en  full 
contour  to  pre^•ent  the  crowding  of  food  between  the  teeth  and  also  to 
prevent  the  first  permanent  molar  from  crowding  them  together  and 
thus  taking  up  room  which  will  be  needed  by  the  bicuspids. 

The  child  should  be  cautioned  against  masticating  too  soon  upon 
proximal  fillings,  although  no  caution  is  needed  in  case  of  occlusal  fill- 
ings hardened  by  the  "wafering"  process. 

Tin  and  gold  are  excluded  from  the  list  of  desirable  filling  materials 
for  temporary  teeth,  not  because  they  are  not  good  filling  materials,  but 
because  the  circumstances  are  such  that  they  cannot  be  used  to  advan- 
tage. Although  a  small  gold  filHng  may  be  inserted  in  a  few  minutes  in 
an  occlusal  cavity,  the  insertion  of  a  large  gold  filling  would  be  inflict- 
ing a  needless  cruelty  on  a  child  on  account  of  the  length  of  time  it  must 
be  held  in  one  position. 

As  the  insertion  of  a  tin  filling  is  nearly  if  not  quite  as  difficult  and 
tedious  an  operation,  it  is  open  to  the  same  objection. 


EXPOSED   PULPS 

On  account  of  the  difficulty  of  properly  capping  an  exposed  pulp  in 
a  deciduous  tooth,  the  operation  should  seldom  be  attempted.  It  is 
better  to  devitalize  the  pulp  and  remove  it. 

Extirpation  of  the  pulp  may  ordinarily  be  accomplished  painlessly  after 
anesthetizing  it  with  cocain  under  pressure. 

If,  however,  for  any  reason,  immediate  extirpation  under  cocain 
anesthesia  becomes  impracticable  in  a  given  case,  then  resort  may  be 
had  to  the  use  of  arsenous  oxid  paste  as  a  devitalizing  agent,  always 
having  in  mind  that  but  a  minute  quantity  of  the  paste  is  required  and 
less  time  is  needed  to  eflFect  the  devitalization  of  a  deciduous  tooth 
pulp  than  that  of  a  permanent  tooth.  Any  of  the  numerous  arsenical 
pulp-devitalizing  pastes  may  be  used  in  children's  teeth  under  reason- 
able restrictions  as  to  quantity  of  the  drug  used  and  length  of  time  of 
the  application. 


EXPOSED  I' U LI'S  679 

The  writer  has  found  the  following  formula^  an  excellent  one: 

I^ — Acidi  arscniosi, 
Morphia?  acetatis, 

Pulv.  opii aa    equal  parts 

Creosoti q.  s.  to  make  paste. 

Why  opium  and  acetate  of  morphine  should  both  be  used  in  the  same 
prescription  is  not  clear,  as  their  properties  are  so  nearly  the  same,  but 
the  paste  has  been  satisfactory  in  devitalizing  pulps  with  no  pain,  or 
with  a  minimum  amount.     Other  formuhe  may  be  equally  satisfactory. 

In  occlusal  cavities  its  application  is  simple.  Excavate  the  softened 
dentin  as  thoroughly  as  possible  without  inflicting  pain,  using  spoon- 
shaped  excavators  to  prevent  puncturing  the  pulp.  If  the  excavation 
can  be  carried  far  enough  to  apply  the  paste  directly  to  the  pulp  its 
action  will  be  more  rapid.  Dry  the  cavity,  apply  a  small  amount,  not 
larger  than  half  a  pinhead  in  size,  with  a  small  probe  and  cover  it  with 
a  pellet  of  cotton,  or  place  in  the  cavity  a  small  pellet  of  cotton  one 
side  of  which  has  been  touched  to  the  paste.  Add  enough  pellets  of 
dry  cotton  to  fill  the  cavity,  then  apply  a  drop  of  sandarac  varnish, 
sufficient  to  saturate  at  least  half  the  depth  of  cotton.  This  is  a  better 
plan  than  dipping  the  pellets  in  the  varnish  before  inserting,  because  an 
excess  of  the  latter  is  apt  to  come  in  contact  with  the  pulp  and  cause 
pain,  or,  penetrating  between  the  paste  and  the  pulp,  may  render  the 
former  inoperative.  Temporary  stoppings,  such  as  Gilbert's,  White's,  or 
Fowler's,  are  excellent  for  sealing  the  cavity,  but  take  a  little  more 
time  than  cotton  and  varnish.  Such  temporary  stopping  should  be  well 
softened  by  heat  to  prevent  pressure  on  the  pulp  in  its  insertion.  A 
good  plan  is  to  warm  the  end  of  the  long  stick  of  stopping  and  press 
it  into  the  cavity,  using  the  remainder  of  the  stick  as  a  handle,  then 
remove  the  surplus  and  smooth  with  a  warm  instrument. 

In  proximal  cavities  extending  near  to  or  under  the  margin,  the  gum 
should  be  protected,  before  applying  the  paste,  as  follows: 

Make,  by  rolling  between  the  fingers,  a  cylinder  of  cotton  as  long 
as  the  width  of  the  tooth  and  about  the  size  of  the  lead  of  a  pencil. 
Saturate  it  with  sandarac  varnish  and  pack  it  between  the  teeth  upon 
the  gum,  extending  part  of  it  below  the  edge  of  the  cavity,  thus  sealing 
this  portion  of  the  cavity  and  reducing  it  nearly  to  the  form  of  an 
occlusal  cavity.  Paste  applied  in  a  proximal  cavity  so  protected  can- 
not flow  upon  the  gum  unless  too  great  a  quantity  has  been  used. 
The  paste  should  be  applied  and  sealed  as  in  an  occlusal  cavity. 

"Devitalizing  fiber"  is  very  satisfactory  and  may  be  used  with  less 
fear  of  its  affecting  the  gum  tissue. 

The  paste  may  be  allowed  to  remain  in  the  cavity  for  from  twelve 
to  forty-eight  hours.    The  possibility  of  the  dressing  being  dislodged,  so 

1  Used  by  Dr.  E.  N.  Clarke  in  the  "fifties." 


GSO  MANAGEMENT  OF  THE  DECIDUOUS  TEETH 

as  to  allow  the  paste  to  come  in  contact  with  the  gum  tissue,  should 
warn  one  to  have  the  patient  return  much  sooner  than  when  the  case 
is  an  occlusal  cavity  from  which  it  is  impossible  for  the  paste  to  escape. 

Much  has  been  said  about  the  danjjjer  of  application  of  arsenic  in 
deciduous  teeth  when  the  roots  are  undergoing  resorption,  but  the 
writer  has  never  seen  any  bad  effects  from  such  use;  still  it  must  be 
admitted  that  the  ratio  of  danger  varies  with  the  degree  of  resorption 
of  the  root.  An  examination  of  Prof.  Peirce's  diagram  (P'ig.  G98)  will 
show  the  average  amount  of  resorption  at  different  ages,  and  enable 
one  to  discriminate.  The  writer  believes  that  the  sensitiveness  of  a 
deciduous  pulp  varies  inversely  with  the  amount  of  resorption  of  the 
root,  and  that  devitalization  is  called  for  in  very  few  cases  in  which 
there  is  danger  of  deleterious  action. 

Prof.  L.  L.  Dunbar  advises  the  use  of  aqua  ammonise  for  devitalizing 
the  pulp  of  a  temporary  tooth,  by  applying  it  on  a  pledget  of  cotton  in 
the  cavity,  one  or  two  applications  being  sufficient  in  most  cases.  This 
plan  is  not  open  to  the  objections  urged  against  the  use  of  arsenous  oxid. 

When  the  pulp  is  devitalized,  open  the  cavity  freely  into  the  pulp 
chamber  and  apply  on  cotton  glycerite  of  tannic  acid.  Leave  this 
about  a  week,  by  which  time  the  pulp  tissue  will  have  become  so 
hardened  by  the  tannin  that  it  may  be  removed  much  more  readily 
than  without  such  treatment. 

The  application  of  mummifying  paste  is  advised  by  many,  after 
devitalization,  to  avoid  the  necessity  of  removing  the  pulp.  If  a  real 
mummifying  paste  can  be  found,  its  application  will  be  the  ideal  treat- 
ment, but  experience  has  demonstrated  that  the  use  of  those  thus  far 
proposed  is  less  satisfactory  than  the  practice  of  radical  remo\al  of 
the  pulp  tissue  and  obliteration  of  the  chamber  and  canals  by  a  suitable 
filling  material. 

FILUNG  PULP  CANALS 

In  the  pulp  canals  apply  iodoform  paste  made  by  mixing  iodoform 
with  oil  of  cassia  and  glycerol  to  such  a  consistence  that  it  can  be  readily 
applied  on  a  probe. 

P'ill  the  pulp  chamber  with  "temporary  stopping"  or  gutta-percha, 
and  the  cavity  with  cement,  gutta-percha,  or  amalgam,  according  to 
indications. 

If  the  tooth  be  very  frail,  fill  the  cavity  with  cement,  because,  owing 
to  its  adhesive  properties,  it  strengthens  the  tooth.  If  the  caAity  be 
proximal  and  it  is  desirable  to  wedge  the  teeth  apart,  use  pink  gutta- 
percha. 

If  the  walls  be  strong  and  some  time  will  elapse  before  the  natural 
exfoliation  of  the  tooth  will  occur,  fill  with  amalgam. 

If  absorption  of  the  roots  occurs,  the  iodoform  in  the  canals  will  not 
interfere.  • 


ALVEOLAR  ABSCESS  G81 

Salol,  wliich  was  ad\'ocated  as  a  root  filling  for  permanent  teeth  by 
Dr.  A.  E.  Mascort/  of  Paris,  France,  is  well  adapted  also  for  filling  the 
canals  of  deciduous  teeth.  "  It  is  a  white  crystalline  powder,  insoluble 
in  water  and  glycerol,  but  soluble  in  alcohol,  ether,  chloroform,  etc.; 
fuses  at  40°  C,  but  crystallizes  quickly  again,"  Melted  together,  salol 
and  aristol,  salol  and  iodoform,  or  salol  and  paraffin,  become  liquid 
like  salol  alone.  After  a  pulp  canal  is  thoroughly  dried  the  salol  may 
be  fused  on  a  small  spatula  and  carried  to  the  canal,  into  which  it  will 
be  taken  by  capillary  attraction,  or  a  broach  may  be  heated  and  inserted 
in  the  salol.  A  small  quantity  will  adhere  like  a  drop  of  liquid  and 
may  thus  be  carried  to  the  canal.  The  heated  broach  may  be  again 
introduced  in  the  canal  to  insure  thorough  application.  Dr.  JMascort 
uses  the  hypodermic  syringe  with  a  small  needle  for  introducing  into 
the  canals.    It  will  crystallize  in  a  very  short  time,  making  a  solid  filling. 


ALVEOLAR  ABSCESS 

The  treatment,  as  with  the  permanent  teeth,  consists  in  removal  of 
the  cause,  i.  e.,  almost  invariably,  a  decomposed  pulp.  Even  here  an 
abscess  seldom  occurs  if  there  be  any  opening  from  the  cavity  of  decay 
to  the  pulp  chamber,  unless  a  foreign  substance  has  stopped  this  opening. 

Make  a  free  opening  into  the  pulp  chamber  and  with  a  syringe 
wash  out  as  much  of  the  contents  as  possible.  Dry  the  chamber  and 
apply  a  dressing  of  formo-cresol  (Buckley)  or  formo-phenol,  the  former 
consisting  of  equal  parts  formalin  and  tricresol,  the  latter  of  equal  parts 
phenol  and  formalin.  The  dressing  should  be  sealed  in  with  a  porous 
dressing  seal,  such  as  cotton  saturated  with  carbolized  resin  or  a  thick 
solution  of  aristol  in  chloroform  and  the  case  dismissed  until  all  inflam- 
matory symptoms  have  subsided,  when  the  roots  may  be  filled  with 
iodoform  paste  and  a  permanent  filling  inserted  in  the  carious  cavity. 

If  a  fistulous  opening  has  formed  through  the  outer  alveolar  plate, 
but  not  through  the  gum,  an  opening  should  be  made  through  the  latter 
with  a  sharp  lancet  about  five  minutes  after  the  application  of  4  per 
cent,  cocain  hydrochlorid  solution  on  a  wad  of  cotton. 

If  a  mild  antiseptic  solution  such  as  electrozone  or  1  per  cent,  potas- 
sium permanganate  can  be  forced  from  the  pulp  chamber  through 
the  root  canals  and  fistulous  opening,  the  accumulated  pus  will  be 
thoroughly  evacuated  and  the  cure  hastened.  As  a  rule,  however,  the 
abscess  disappears  after  the  cause  is  removed,  that  is,  the  putrescent  or 
decomposed  contents  of  the  pulp  chamber  and  canals. 

After  drying  the  pulp  chamber  and  canals,  apply  iodoform  paste 
therein  and  seal  the  cavity  for  a  few  days  with  temporary  stopping. 

1  Dental  Cosmos,  1894,  p.  352. 


682  MANAGEMENT  OF  THE  DECIDUOUS  TEETH 

When  tlie  inflammation  of  the  pericementum  has  disappeared  the  pulp 
chamber  and  canals  may  l)e  filled  as  hefore  directed. 

Often  the  inflammation  of  the  pericementum  will  be  so  great,  or  in 
popular  expression  the  tooth  so  "sore"  to  the  toucii,  when  the  case  is 
presented  that  at  the  first  sitting  nothing  more  can  be  done  than  to 
make  an  oj)ening  into  the  pulp  chamber  to  allow  the  escape  of  pus  or 
gases  of  decomposition.  This  relieves  the  pain,  and  manipulation  and 
treatment  mav  be  left  until  the  inflammation  has  subsided. 


PROPHYLACTIC  TREATMENT 

This  lies  more  in  the  hands  of  the  parent  than  of  the  practitioner,  but 
should  be  strongly  urged  by  the  latter  upon  the  former.  The  nurse 
or  parent  should  begin  early  to  clean  the  child's  teeth  by  means  of  a 
cloth  wrapped  around  the  finger.  If  the  teeth  cannot  be  kept  clean  in 
this  manner  a  small  brush  should  be  used,  especially  after  eruption  of 
the  molars.  Floss  silk  should  be  used  daily  between  the  teeth.  One  end 
of  the  silk  should  be  held  in  each  hand  so  as  to  pass  over  the  end  of 
each  index  finger  and  be  made  taut  between  them.  This  taut  part 
can  be  pressed  down  between  the  teeth  and  passed  up  and  down  against 
the  proximal  surface  of  each  tooth,  then  one  end  of  the  thread  should 
be  released  and  pulled  through  the  interdental  space. 
.  This  will  drag  out  any  particles  of  food  that  may  be  there,  and  is 
much  better  than  the  toothpick  for  the  purpose.  If  particles  of  meat 
or  other  food  have  lodged  so  firmly  that  the  plain  waxed  silk  will  not 
dislodge  them,  tie  a  single  knot  in  the  thread  and  pull  that  through. 
;  This  cleansing  with  the  cloth,  brush,  and  silk  should  be  done  before 
the  child  retires  at  night,  for  that  is  the  "period  of  decay."  The  parts 
are  at  rest  longer  than  at  any  other  time,  and  the  fluids  of  the  mouth 
are  not  kept  in  circulation  between  the  teeth  by  means  of  the  tongue, 
lips,  and  cheeks.  Theoretically  the  teeth  should  be  thus  thoroughly 
cleaned  after  each  meal,  but  "satiety  breeds  disgust,"  and  it  is  not 
best  to  insist  on  more  than  will  probably  be  accomplished. 

Children  will  soon  learn  to  use  the  brush  and  floss  silk  themselves, 
and  finding  the  mouth  much  more  comfortable  when  "clean,"  they  will 
endeavor  to  keep  it  so.  I\Iany  a  child  has  been  denied  candy  for  years 
from  the  belief  that  "sweets  decay  the  teeth,"  but  parents  may  be 
assured  that  no  harm  will  be  done  by  the  moderate  use  of  pure  candy 
if  the  "sweet"  is  not  allowed  to  remain  between  and  around  the  teeth 
until  it  becomes  acid,  and  that  may  be  prevented  by  cleansing  the  teeth 
after  the  candy  or  sugar  is  eaten.  A  child  may  be  taught  cleanliness  in 
this  manner  who  would  be  only  taught  rebellion  by  the  repeated  denial 
of  sweets,  the  reasons  of  which  he  cannot  understand. 

Prophylactic  mouth  washes  should  be  used — such  as  Listerine  diluted 
to  a  10  per  cent,  solution. 


CHAPTER    XXI 

ORTHODONTIA 

By  EDWARD  H.  ANGLE,  M.D,,  D.D.S. 

OCCLUSION 

"Substantial  progress  in  any  science  is  impossible  in  the  absence  of  a 
working  hypothesis  which  is  universal  in  its  application  to  the  phenomena 
pertaining  to  the  subject-matter.  Indeed,  until  such  a  hypothesis  is 
discovered  and  formulated,  no  subject  of  human  investigation  can 
properly  be  said  to  be  within  the  domain  of  the  exact  sciences.  It 
enables  one  skilled  in  the  science  to  practise  it  with  a  certainty  of 
results  in  exact  proportion  to  his  knowledge  of  its  principles  and  skill 
in  applying  them  to  the  work  in  hand." — Hudson. 

Orthodontia}  is  the  science  of  occlusion  of  the  teeth  and  the  art  of 
correcting  malocclusion. 

Occlusion  is  the  basis  of  the  science  of  orthodontia.  The  shapes  of 
the  cusps,  crowns,  and  roots,  and  even  the  very  structural  material  of 
the  teeth  and  their  attachments,  are  all  designed  for  the  purpose 
of  making  occlusion  the  one  grand  object,  in  order  that  they  may  best 
serve  the  chief  purpose  for  which  they  were  intended,  namely,  the 
cutting  and  grinding  of  food.  We  will  define  occlusion  as  being  the 
normal  relations  of  the  occlusal  inclined  'planes  of  the  teeth  when  the  jaws 
are  closed. 

Malocclusion  of  the  teeth  is  but  the  perversion  of  their  normal  relations. 
It  can  be  studied  intelligently  only  from  the  basis  of  the  normal,  and 
to  begin  its  study  without  first  being  familiar  with  the  normal  would 
be  as  unfruitful  as  the  study  of  the  pathology  of  any  other  of  the  struc- 
tures of  the  body  without  first  mastering  their  anatomy  and  physiology. 

There  must  be,  then,  clearly  fixed  in  the  mind  of  the  student  of  ortho- 
dontia not  only  Nature's  plan  of  the  normal  denture  when  complete, 
but  also  of  its  beginnings — the  growth  and  development  of  parts,  and 
their  co-relations. 

The  normal  human  denture  in  its  completeness  includes  not  only  the 
jaws,  alveolar  process,  dental  arches,  and  especially  the  teeth  and  peri- 
dental membrane,  which  to  the  orthodontist  are  of  prime  importance, 
since  on  them  chiefly  his  operations  are  performed,  but  also  the  muscles 

^  From  the  Greek,  opdog,  straight ;  oJ(5uf,  tooth. 

(683) 


684  ORTHODONTIA 

of  lips,  cheeks,  tongue,  and  mouth,  the  nasal  passages,  palate,  and 
throat,  as  these  assist  the  teeth  in  performing  their  functions.  They 
are  also  powerful  factors  in  establishing  and  maintaining  either  har- 
mony or  inharmony  in  the  development  and  arrangement  of  the  teeth, 
and  this  just  in  proportion  as  they  are,  singly  or  collectively,  normal 
or  abnormal  in  their  own  development  and  functions. 

It  is,  of  course,  not  within  the  ])rovince  of  a  brief  treatise  on 
orthodontia  to  teach  as  minuteh-  and  thoroughly  as  is  necessary  to 
a  complete  understanding  thereof,  the  embryology,  histology,  and 
anatomy  of  the  human  denture.  The  student  is  therefore  strongly 
recommended  to  their  study  elsewhere,  and  especially  to  the  works 
of  Drs.  Noyes,  Black,  Broomell,  Cryer,  and  Kyle.  A  thorough 
knowledge  of  the  individual  teeth  is  of  such  inestimable  value  to  the 
orthodontist  that  the  student  is  urged  to  carve,  or  model  in  clay,  the 
different  tooth  forms,  as  in  no  other  way  will  there  be  such  a  vivid 
impression  stamped  upon  his  mind  of  the  correct  outlines  of  their  crowns 
and  the  positions  and  relative  proportions  of  their  cusps,  together  with 
their  marginal,  triangular,  and  oblicjue  ridges,  their  grooves  and  sulci, 
and  their  proper  relations  to  the  teeth  of  their  own  arch  and  to  those  of 
the  opposing  arch. 

Nature  in  building  the  dental  apparatus  requires  a  long  period  of 
time — twenty  years  or  more — and  from  the  beginning  of  the  formation 
of  the  dental  follicle  and  the  tissues  that  support  and  precede  it,  to  the 
eruption  of  the  last  third  molar,  she  works  in  accordance  with  a  definite 
plan  toward  a  definite  end,  viz.,  the  production  of  a  type  that  has  been 
the  type  of  man's  denture  as  long  as  man  has  been  man. 

By  referring  to  Figs.  703  and  704,  which  represent  the  teeth  in  normal 
occlusion,  it  will  be  seen  that  each  dental  arch  describes  a  graceful 
curve,  and  that  the  teeth  in  these  arches  are  so  arranged  as  to  be  in 
greatest  harmony  with  their  fellows  in  the  same  arch,  as  well  as  with 
those  in  the  opposite  arch. 

In  their  normal  relations  the  external  curve  of  the  lower  arch  is 
slightly  smaller  than  that  of  the  upper,  so  that  in  occlusion  the  labial 
and  buccal  surfaces  of  the  teeth  of  the  upper  jaw  slightly  overhang 
those  of  the  lower. 

The  mesio-buccal  cusp  of  the  upper  first  molar  is  received  in  the 
buccal  groove  of  the  lower  first  molar.  The  teeth  posterior  to  the  first 
molars  engage  with  their  antagonists  in  a  precisely  similar  way;  those 
anterior  to  the  first  molars  interlock  with  one  another  in  the  interspaces 
until  the  incisors  are  reached;  of  these,  the  upper  usually  overhang  the 
lower  about  one  third  the  length  of  their  crowns,  although  the  length  of 
overbite  varies  according  to  the  ty'pal  pattern  of  the  teeth. 

The  upper  central  incisor  being  broader  than  the  lower,  it  necessarily 
extends  beyond  it  distally,  overlapping  in  addition  about  one-half  of 
the  lower  lateral  incisor;  the  upper  lateral  occludes  with  die  remaining 


OCCLUSION 


G85 


Pre:.   703 


Typical  occlusion.     (Cryer.) 


Fig.  704. 


Normal  occlusion. 


686 


ORTIIODOATIA 


portion  of  this  tootli  and  witli  the  mesial  incline  of  the  lower  canine;  the 
mesial  incline  of  the  upper  canine  occludes  with  the  distal  incline  of  the 
lower  canine,  the  distal  incline  of  the  upper  occluding  with  die  mesial 
incline  of  the  buccal  cusp  of  the  lower  first  premolar.  In  the  same 
order  the  series  of  buccal  cusps  of  the  premolars  occlude — the  mesial 
incline  of  each  upper  occluding  with  the  distal  incline  of  the  correspond- 
ing lower  tooth. 

The  distal  incline  of  the  buccal  cusp  of  the  second  upper  premolar 
occludes  with  the  mesial  incline  of  the  mesio-buccal  cusp  of  the  lower 
first  molar.  The  mesial  incline  of  the  mesio-buccal  cusp  of  die  upper  first 
molar  occludes  with  the  distal  incline  of  the  mesio-buccal  cusp  of  the 
lower  first  molar;  the  distal  incline  of  the  mesio-l)uccal  cusp  of  the  upper 


Fig.  705 


Normal  occlusion. 


first  molar  occludes  with  the  mesial  incline  of  the  disto-buccal  cusp 
of  the  lower  first  molar;  the  mesial  incline  of  the  disto-buccal  cusp  of 
the  upper  first  molar  occludes  with  the  distal  incline  of  the  disto-buccal 
cusp  of  the  lower  first  molar,  and  the  distal  incline  of  the  disto-buccal  cusp 
of  the  upper  first  molar  occludes  Avith  the  mesial  incline  of  the  mesio- 
buccal  cusp  of  the  lower  second  molar.  This  same  order  is  continued 
with  the  buccal  cusps  of  the  second  and  third  upper  molars,  the  distal 
incline  of  the  disto-buccal  cusp  of  the  upper  third  molar  having  no 
occlusion. 

It  will  thus  be  seen  that  each  of  the  teeth  in  both  jaws  has  two  antag- 


OCCLUSION 


687 


onist.s  or  supports  in  tlic  opposite  jaw,  except  the  lower  central  incisor 
and  upper  third  molar. 

As  the  inclined  planes  match  and  harmonize  most  perfectly  in  the 
bucco-occlusal  relations  of  the  teeth,  so  there  is  a  similar  arrangement 
in  their  linguo-cx-clusal  relations,  except  that  the  lingual  cusps  of  the 
lower  premolars  and  molars  project  beyond  those  of  the  upper  teeth 
into  the  oral  space,  as  shown  in  Fig.  705. 

Likewise,  in  the  transverse  arrangement,  the  buccal  cusps  of  the  lower 
molars  and  premolars  rest  between  the  buccal  and  lingual  cusps  of  the 
upper  molars  and  premolars,  and  the  lingual  cusps  of  the  upper  molars 
and  premolars  rest  between  the  buccal  and  lingual  cusps  of  the  lower 
molars  and  uremolars,  as  in  Fig.  706. 


Fig.  706 


Typical  occlusion  of  molars;  transverse  view.     (Cryer.) 


The  grinding  surfaces  are  thus  enormously  increased  in  extent  and 
efficiency  over  what  would  be  possible  if  they  consisted  of  a  single  row 
of  cusps  or  of  plane  surfaces. 

But  increase  of  masticating  surface  is  not  the  only  reason  for  this 
complex  interdigitation  of  the  cusps  and  inclined  planes  of  the  teeth,  it 
is  likewise  of  great  importance  in  providing  for  the  teeth  a  mutual 
support. 

The  sizes,  forms,  interdigitating  surfaces,  and  positions  of  the  teeth 
in  the  arches  are  such  as  to  give  to  one  another,  singly  and  collectively , 
the  greatest  possible  support  in  all  directions. 

This  is  the  pattern,  the  form,  the  type  of  the  normal  in  occlusion — 
the  normal  denture. 

In  the  normal  building  of  the  human  denture,  nature  works  toward  a 

definite  end  to  produce  the  most  efficient  parts  with  the  most  efficient 

.  arrangement  of  these  parts  that  they  may  in  function  be  most  efficient. 

Each  tooth  is  not  only  in  harmonious  relation  with  every  other  tooth,  but 

helps  to  maintain  every  other  tooth  in  these  harmonious  relations,  for 


088  ORTIIODOXriA 

the  cusps  interlock  and  each  inclined  occlnsid  picmc  serves  to  prevent 
each  tooth  from  sliding  out  of  position,  and  further,  to  wed(je  it  into  posi- 
tion if  but  slightly  malposed,  that  is,  if  not  beyond  the  normal  inlhience 
of  the  incHned  planes. 

A  careful  study  of  the  relations  of  the  inclined  occlusal  j)lanes  and 
the  marginal,  triangular,  and  oblique  ridges,  in  connection  with  the 
movements  of  the  jaw,  cannot  fail  to  impress  thoughtful  persons  not 
only  with  the  influence  which  these  exert  in  maintaining  each  individual 
tooth  in  correct  position,  but  as  well  Uieir  wonderful  efficiency  for  incising 
and  triturating  the  food  required  by  omnivorous  man,  and  with  their 
marvellous  forms  and  arrangement  for  self-cleansing  and  consequent 
self-preservation.  So  perfect  is  the  plan  in  the  relations  of  the  teeth  as 
a  whole  that  each  cusp  or  part  of  a  cusp  contributes  perfectly  to  the 
balance,  harmony,  and  efficiency  of  all,  and  consecjuently  die  mesio- 
distal  diameter  of  a  tooth,  or  any  portion  of  it,  cannot  be  sacrificed 
without  proportionately  disturbing  the  delicate  balance  and  integrity  of 
form  and  function  of  the  whole.  To  one  versed  in  occlusion  no  argument 
is  needed  to  impress  the  importance  of  the  complete  and  perfect  restora- 
tion to  contour  of  missing  portions  of  teeth,  or  of  the  adjustment  to  normal 
position  of  those  teeth  that  are  malposed. 

Not  only  are  the  individual  tooth  patterns  and  the  relations  of  the  teeth 
most  perfectly  designed  for  performing  their  functions,  but  j)robably 
no  other  forms  or  relations  could  produce  so  beautiful  and  artistic  an 
effect  as  an  individual  feature,  or  give  so  much  of  beauty  in  lines  and 
expression  to  the  face.  The  denture,  with  the  teeth  in  normal  occlusion, 
is  a  marked  element  of  beauty  to  any  face,  however  imperfect  in  other 
respects. 

There  is  great  harmony  in  the  lines  of  the  teeth,  although  all  vary, 
the  result  being  most  pleasing.  How  the  beauty  of  the  central  incisor 
would  be  impaired  if  its  mesial  lines  were  the  same  as  its  distal  lines. 
How  much  less  pleasing  would  be  the  result  if  the  lateral  incisor  were 
of  the  same  size  as  the  central,  or  even  of  the  same  pattern,  instead  of 
possessing  the  majesty  of  a  pattern  and  proportionate  size  of  its  own.  It  is 
like  the  central,  yet  how  beautiful  in  its  difference.  The  canine,  although 
reseml)ling  both  central  and  lateral,  adds  much  beauty  to  the  whole 
in  the  lines  peculiar  to  its  own  pattern,  and  how  much  the  general  effect 
is  enhanced  by  the  lateral  incisor  being  shorter  and  slightly  less  prom- 
inent in  the  line  of  occlusion  than  either  the  central  or  canine.  In 
orthodontic  operations,  or  in  unanatomically  fashioned  dentures,  when 
the  lateral  is  made  prominent  or  of  the  same  length  as  the  other  teeth,  the 
result  is  pronouncedly  unpleasing.  Again,  how  unpleasing  is  the  effect 
when  these  beautiful  lines  are  impaired  by  grinding  any  of  the  marginal 
surfaces — a  fact  that  should  lend  caution  to  the  hand  of  both  orthodontist 
and  dentist. 


OCCLUSION  689 

Key  to  Occlusion. — According  to  nature's  plan  of  the  human  denture 
all  of  the  teeth  are  essential,  yet  in  function  and  influence  some  are  of 
greater  importance  than  others,  the  most  important  of  all  being  the  first 
permanent  molars.  They  are  the  largest  of  the  teeth  and  the  firmest 
in  their  attachment,  which,  together  with  their  location  in  the  arches, 
makes  them  the  most  important  of  all  the  teeth  in  the  function  of  masti- 
cation. By  the  lengths  of  their  crowns  they  also  determine  the  extent 
of  separation  of  the  jaws  and  length  of  bite,  and  in  this,  as  well  as  in 
many  other  ways,  are  factors  in  the  artistic  proportions  of  the  face. 
Being  the  first  of  the  permanent  teeth  to  take  their  positions  in  the  arches, 
they  exercise  great  control  over  the  positions  which  the  other  permanent 
teeth  anterior  and  posterior  to  them  shall  occupy  as  they  erupt  at  their 
respective  periods  and  take  their  respective  positions  in  the  arches. 
As  they  are  already  developed  and  firmly  attached  in  the  alveolar  process 
when  the  other  permanent  teeth  appear,  the  latter  are  built  into  the 
dental  apparatus  around  them,  as  it  were.  They  are  not  only  the 
most  constant  in  the  time  of  taking  their  positions,  but  by  far  the  most 
constant  in  taking  their  normal  positions,  especially  the  upper  first 
molars. 

A  better  understanding  of  the  reason  why  these  teeth  take  correct 
positions  is  gained  if  we  will  but  remember  that  theirs  are  the  first 
permanent  tooth  germs  formed,  and  also  that  they  are  the  first  of  the 
permanent  teeth  to  develop  and  erupt,  which  they  do,  unhampered, 
immediately  posterior  to  the  twenty  teeth  comprising  the  deciduous 
set,  and  that  the  deciduous  teeth  are  free  to  erupt  normally  according 
to  nature's  plan,  under  the  most  favorable  conditions,  and  do  so 
nearly  always  in  normal  occlusion  and  in  perfect  accordance  with  the 
requirements  for  harmony  and  beauty  of  the  developing  child's  face. 
So  the  permanent  molars  in  erupting  are  not  only  unhampered  in  taking 
their  positions,  but,  on  the  contrary,  they  are,  as  it  were,  guided  into 
and  guarded  in  correct  positions  by  the  usually  normal  child  denture 
anterior  to  them  (Fig.  707),  and  by  their  normal  locking  on  eruption 
is  made  possible  the  normal  eruption  and  locking  of  all  the  other 
teeth  both  anterior  and  posterior  to  them  in  both  lateral  halves  of 
each  arch. 

So  important  is  the  influence  of  these  teeth  in  the  building  of  the 
dental  apparatus  that  we  believe  nature  exercises  the  greatest  care  in 
locating  them  in  the  line  of  occlusion,  especially  the  upper  first  molars^ — 
which  we  call  the  keys  to  occlusion — and  so  places  them  that  the  rest  of 
the  dental  apparatus  may  be  completed  normally,  and  if  completed 
normally  and  in  harmony  with  these  teeth,  the  dental  apparatus  will 
be  in  best  balance  and  harmony  with  the  skull  and  the  other  essential 


^  Angle,  "The  Upper  First  Permanent  Molar  as  a  Basis  of  Diagnosis,"  Items  of 
Interest,  June  1906. 
44 


690 


ORTHODONTIA 


organs,  as  the  eyes,  the  ears,  the  nose,  etc. — indeed,  with  the  strurturai 
type  of  the  individual  throughout. 


Fig.  707 


Normal  denture  of  ohiM. 


The  fact  that  the  upper  first  permanent  molar  varies  considerably 
mesially  or  distally  as  to  its  location  in  different  individuals,  which  is 
always  noted  in  anything  like  an  extensive  study  of   the  subject,  has 


OCCLUSION  691 

led  superficial  students  to  regard  these  positions  as  abnormal,  taken  by 
chance,  and  often  out  of  harmony  with  other  principles  in  the  anatomy 
of  individuals,  but  in  reality  these  variations  are  to  be  expected,  and 
are  necessary  in  the  creation  of  different  types  and  different  individuals. 
As,  for  example,  this  molar  is  found  to  be  located  farther  anterior  in  its 
relation  to  the  skull  in  some  of  the  lower  orders  of  man  and  the  primates 
than  in  the  highly  developed  civilized  man,  and  even  in  civilized  man 
the  mesio-distal  position  of  this  tooth  may  vary  in  each  individual,  yet 
this  is  necessary  in  the  typal  requirements. 

Theoretically  the  first  upper  molars  may  differ  slightly  in  their  mesio- 
distal  position,  even  in  each  lateral  half  of  the  dental  arches  of  an  appar- 
ently normal  individual,  just  as  the  eyes  or  ears  may  slightly  differ  as 
to  height  or  location  in  the  same  person.  Probably  the  first  molars  are 
never  exactly  constant  as  to  the  two  sides,  but  we  insist  that  this  is  but 
natural  and  in  keeping  with  the  rest  of  the  anatomy,  and,  when  slight, 
should  not  be  regarded  as  an  abnormality. 

And  finally,  that  nature  may  err  in  the  mesio-distal  locating  of  these 
molars  is  doubtless  possible,  for  we  know  the  unfortunates  classified  as 
"freaks"  are  the  result  of  her  anatomical  errors,  but  we  must  remember 
that  freaks  are  very  rare,  and  we  believe  that  nature  so  very  rarely 
errs  in  the  locating  of  the  first  upper  molars — the  very  cornerstones,  as 
it  were,  in  the  foundation  of  the  structure  of  an  organ  so  essential  to  the 
whole  physical  economy  as  the  dental  apparatus — as  to  make  it  a  matter 
of  little  or  no  concern  to  us  except,  possibly,  in  research  work.  The 
writer  has  been  unable  to  find,  after  much  study,  a  single  case  in  an 
unmutilated  denture  at  maturity  where  it  would  seem  to  him  that 
nature  had  erred  in  not  locating  these  most  important  teeth  so  as  to  be 
in  best  keeping  with  the  other  anatomical  factors  of  the  type.  Indeed, 
he  is  also  greatly  impressed,  after  the  study  of  a  large  number  of  cases, 
with  the  constancy  of  the  normality,  also,  of  their  linguo-buccal  positions, 
in  accordance  with  the  age  and  growth  of  the  individual,  even  when 
other  unfavorable  influences  exist,  unless  the  teeth  are  forced  buccally 
or  lingually  by  locking  in  buccal  or  lingual  occlusion,  as  in  Fig.  708, 

So  it  will  be  seen  that  the  reasons  for  regarding  these  teeth  as  the 
keys  to  occlusion  are  most  logical  and  conclusive.  It  is,  therefore,  on 
their  positions  and  the  relations  of  their  antagonists  with  them  that  the 
classification  and  diagnosis  of  malocclusion  must  be  based. 

The  first  upper  molars  are  sometimes  forced  to  take  mesial  mal- 
positions temporarily,  or  during  the  growth  of  the  denture,  as  a  result 
of  mutilation  of  either  deciduous  or  permanent  teeth,  but  this  is  only 
temporary,  and  the  extent  of  their  variation  from  normal  position  is 
easily  determined  and  allowance  for  it  made,  and  at  maturity,  or  after 
the  eruption  of  the  second  and  third  molars,  it  is  probably  rarely,  if  ever, 
even  in  these  cases,  that  an  upper  first  permanent  molar  is  found  mesial 
to  its  correct  position.  This  subject  is  further  discussed  in  the  section 
on  Premature  Loss  of  Deciduous  Teeth — ^Etiology. 


692 


ORTHODONTIA 


Line  of  Occlusion. — ^Yritc^s  on  orthodontia  have  long  l)ccn  in  the 
habit  of  making  use  of  an  imaginary  hne,  known  as  "the  teetii  in  ahgn- 
ment,"  and  "the  line  of  the  arch,"  from  which  to  note  regular  and 
irregular  alignment  of  the  crowns  of  the  teeth.  It  has  most  often  referred 
to  the  general  line  of  each  individual  arch,  as  outlined  by  the  crowns 
of  the  teeth,  regardless  of  their  number  or  position,  or  of  the  relations 
of  such  lines  to  the  skull.  In  this  way  two  lines  of  occluson  are  often 
inferred,  one  for  each  arch,  which  may  or  may  not  have  direct  relation 
one  to  the  other.  In  reality,  as  used,  it  has  been  vague  and  indefinite. 
So  far  as  the  writer  is  aware,  none  has  comprehended  its  full  meaning  or 
importance. 


Fig.  708 


Buccal  and  lingual  occlusion. 


That  we  should  have  a  line  from  which  to  note  variations  from  the 
normal  is  highly  important,  but  that  its  meaning  is  deeper  and  that 
it  has  a  far  greater  significance  to  the  student  of  orthodontia  than  above 
indicated,  the  writer  is  fully  convinced,  and  he  would  define  the  line 
of  occlusion  as  being  the  line  with  which,  in  size,  in  form,  and  in  position 
according  to  type,  the  teeth  must  he  in  harmony  if  in  normal  occlusion. 

There  can  be,  then,  but  one  true  line  of  occlusion,  and  it  is  the  normal 
architectural  line  on  which  the  dental  apparatus  was  designed.  The 
ideal  line  was  intended  to  govern  not  only  the  length,  breadth,  and 
peculiar  curve  of  the  dental  arches,  but  the  size  and  pattern  of  each  tooth, 


OCCLUSION 


09;] 


cusp,  and  inclined  plane  composing  these  arches.  And  more  than  this: 
that  as  the  dental  apparatus  is  only  a  part  of  the  great  structure — the 
human  body — each  part  and  organ  of  which  was  fashioned  according 
to  lines  of  design,  it  must  have  been  intended  that  the  line  of  occlusion 
should  be  in  harmony  in  form  and  position  with,  and  in  proper  relation 
to,  all  other  parts  of  the  great  structure,  according  to  the  inherited 
type  of  the  individual.  Hence  its  majesty,  and  according  to  our  con- 
ception of  it  must  be  our  ability  to  comprehend  not  only  the  art  require- 
ments in  each  case  we  treat,  l)ut  as  well  must  it  govern  our  conception 
of  the  requirements  of  the  position  of  the  teeth  in  occlusion  and  the 
various  operations  in  treatment.  The  line  of  occlusion,  then,  is  more 
than  the  tangible  or  material.  It  may  be  regarded  as  the  basic  ideal  of 
the  dental  apparatus,  the  comprehension  and  appreciation  of  which 
will  grow  in  proportion  as  our  knowledge  of  the  science  of  occlusion 
unfolds. 

Fig.  709 


Bonwill   diagram. 


We  may  speak  of  moving  a  tooth  of  the  lower  arch  into  the  line  of 
occlusion,  or  of  moving  a  tooth  of  the  upper  arch  into  the  line  of 
occlusion,  but  it  must  always  be  remembered  that  there  can  be  but 
one  true  line  of  occlusion,  or  the  line  with  which  each  tooth  must  be 
in  perfect  harmony  if  in  normal  occlusion. 

It  was  long  ago  suggested  by  Dr.  Bonwill,  and  very  recently  by 
others,  that  the  well-known  "Bonwill  law,"  so  called,  could  be  made 
use  of  in  predetermining  the  form  and  position  of  the  line  of  occlusion 
in  cases  of  malocclusion,  the  curve  and  width  of  the  arch  being 
determined  by  the  combined  diameters  of  the  upper  central  and  lateral 
incisors  and  canine  on  one  side,  as  per  the  familiar  diagram  shown  in 
Fig.  709. 

The  absurdity  of  this  proposition  is  easily  made  apparent  when  we 


694 


ORTHODONTIA 


remember  that  this  would  necessitate  the  same  form  of  arch  for  every 
indivichial  possessing  the  same  diameter  of  incisors  and  canines,  jointly, 
regardless  of  the  demands  of  the  facial  type,  when  we  know  that  in 
reality  the  width  and  form  of  the  arch  must  vary,  regardless  of  the  width 
of  the  incisors  and  canines,  according  to  the  demands  of  the  type. 
This  is  strikingly  illustrated  by  the  four  skulls  shown  in  Fig.  710.  It 
will  be  seen  that  two  of  the  arches  are  broad  and  short  and  the  other 
two  long  and  narrow,  notwithstanding  the  fact  that  the  diameters  of 
incisors  and  canines  may  have  been  equal  in  all  four  cases. 


Fig.  710 


•^■•;  I'M.  V.--W  ^;yi 


But  by  further  study  of  these  skulls  it  will  l)e  seen  that  each  arch  is 
in  fine  conformity  with  the  demands  of  the  architectural  lines  of  the  skull 
to  which  it  belongs.  The  extremely  broad  and  short  arches  are  in 
perfect  balance  with  the  very  broad  and  short  skulls,  while  the  long, 
narrow  arches  are  also  exactly  in  keeping  with  the  extremely  long  and 
narrow  skulls,  and  the  patterns  of  the  teeth  are  in  like  manner  in  perfect 
accord  with  the  architectural  demands  of  not  only  the  skulls  to  which 
they  belong,  but  to  every  portion  of  them.  To  make  this  point  clear — 
if  the  face  and  skull  are  long  and  narrow,  the  dental  arch  will  be  long 
and  narrow,  and  the  body  throughout  will  have  the  same  typal  charac- 
teristics. 

If  the  face  and  skull  are  round,  the  dental  arch  will  be  propor- 
tionately round  and  broad,  and  the  incisors  and  cuspids  will  conform 
more  nearly  to  the  arc  of  a  true  circle,  and  the  rest  of  the  body  will  be  of 
a  corresponding  t>'pe.  While  with  a  type  of  face  and  skull  more  nearly 
approximating  a  cube,  the  dental  arch  and  all  the  rest  of  the  body  will 
be  found  to  correspond,  and  this  same  harmony  and  balance  between 
dental  arch,  face,  skull,  and  the  rest  of  the  l)ody  will  also  hold  true  with  all 
individuals  of  whatever  race  who  represent  all  the  degrees  and  variations 
between  these  pronounced  types.    The  writer  believes  this  is  a  typal  law.i 


^  The  writer  first  called  attention  to  this  law  in  a  paper  read  before  the  American 
Society  of  Orthodontists,  September  29,  1905.     See  Items  of  Interest,  June,  1906. 


OCCLUSION  695 

having  few,  if  any,  variations,  which  anyone  can  verify  by  the  study  of 
skulls  or  of  individuals. 

As  there  can  be  no  fixed  rules  of  measurement  for  predetermining 
the  proper  form  of  the  line  of  occlusion  in  cases  of  malocclusion,  any 
more  than  there  can  be  fixed  rules  for  determining  the  typal  balance  of 
the  facial  lines,  for  which  artists  have  so  long  striven  in  vain,  it  seems 
to  the  writer  that  the  best  the  orthodontist  can  do  is  to  secure  normal 
relations  of  the  teeth  and  a  typal  form  of  the  arch  as  nearly  correct  as  he 
is  able  to  determine,  leaving  the  finer  adjustment  of  this  form  to  be 
worked  out  by  nature  through  her  forces  governing  occlusion,  which 
must,  it  any  event,  finally  triumph. 

Forces  Governing  Normal  Occlusion. — As  we  have  already  seen,  the 
inclined  planes  of  the  cusps  of  the  teeth  play  an  important  part  in 
maintaining  normal  occlusion.  They  also  exercise  the  most  powerful 
influence  in  directing  the  positions  of  the  teeth  during  their  eruption. 

When  the  teeth  first  emerge  from  the  gums  their  considerable  dis- 
placement is  often  noticeable,  but  this  need  occasion  no  uneasiness, 
provided,  as  eruption  progresses,  their  cusps  pass  under  the  influence  of 
normally  placed  opposing  cusps.  But  if  they  pass  beyond  this  influence 
into  abnormal  relations,  they  will  not  only  be  further  deflected  from  their 
own  proper  positions,  but  may  displace  the  opposing  teeth  and  those 
subsequently  to  erupt  as  well,  even  to  the  extent  of  the  disarrangement 
of  the  entire  thirty-two  teeth,  as  is  possible  from  the  mal-locking  of  the 
first  permanent  molars.  So  there  may  be  times  when  the  dividing  line 
between  harmony  and  inharmony  is  very  slight,  hence  the  importance 
of  careful  attention  during  the  important  period  covering  the  eruption 
of  the  permanent  teeth,  especially  the  beginnings. 

Harmony  between  the  complete  upper  and  lower  arches  is  also  power- 
fully promoted  by  their  normal  action  and  reaction  upon  each  other 
through  the  teeth.  As  the  teeth  of  the  lower  arch  erupt  before  their 
antagonists  of  the  upper  arch,  and  are  consequently  to  an  extent  fixed 
in  their  positions  before  the  latter  appear,  it  follows  that  the  lower  arch 
is  the  form  over  which  the  upper  is  moulded.  In  other  words,  the  lov/er 
arch  exerts  a  modifying  influence  on  the  form  of  the  upper.  Of  course, 
the  upper  reacts  upon  the  lower,  but  it  is  unquestionable,  in  the  writer's 
opinion,  that  the  lower  arch  is  the  more  important  factor  in  determining 
the  form  of  the  dental  arches  than  the  upper,  as  has  formerly  been  taught. 

From  what  has  been  said  it  may  be  readily  seen  how  greatly  each  arch 
contributes  to  the  other  in  maintaining  its  form  and  size  when  the 
teeth  are  in  normal  occlusion,  and  how  pressure  abnormally  exerted 
on  any  tooth  or  teeth  would  be  resisted  by  all  the  other  teeth.  For 
example,  pressure  exerted  on  the  labial  surfaces  of  the  upper  incisors 
would  be  resisted  not  only  by  all  the  upper  teeth  acting  as  blocks  of 
stone  do  in  an  arch  of  masonry,  but  also  by  the  teeth  of  the  lower  arch 
acting  tlirough  occlusion. 


C96 


ORTHODONTIA 


Inversely,  then,  one  arch  cannot  he  aUered  in  shape  without  modi- 
fying that  of  tlie  other,  nor  can  it  be  altered  in  size  without  soon  exer- 
cising a  marked  effect  on  the  other. 

The  normal  positions  of  the  teeth  and  the  normal  sizes  and  relations 
of  the  arches  are  further  powerfully  influenced  by  another  force,  namely, 
muscular  pressure,  the  tongue  acting  upon  the  inside  and  the  lips  and 
cheeks  upon  the  outside  of  the  arches.  The  latter,  if  normal  in  develop- 
ment and  function,  serve  to  keep  the  arches  from  spreading,  as  do  hoops 
upon  the  staves  of  a  cask;  the  former  prevents  too  great  encroachment 
upon  the  oral  space,  and  each,  if  normal  in  function,  contributes  in  like 
proportion  to  the  harmony  of  balance.  The  upper  lip  will  be  found 
to  rest  evenly  in  contact  with  the  gums  and  upper  three-fourths  of  the 
labial  surfaces  of  the  upper  incisors,  leaving,  however,  about  one-fourth 


Fig. 

711 

^^^H 

I 

I^H 

^^H  .^«t-!  '  ^g^mmmiam^ 

Mifll 

■nnnmflPml^l 

^^L.Jr^ 

r 

•  r^-    -^^m^^^^^^ 

B^--'*':^ 

i^ 

of  the  occlusal  ends  of  the  central  incisors  and  laterals  to  be  covered 
by  the  edge  of  the  lower  lip,  so  that  normally  there  is  a  restraining 
force  exerted  upon  the  upper  incisors  by  both  upper  and  lower 
lips. 

This  force  is  exerted  automatically  in  response  to  almost  every  emotion, 
and  results  in  maintaining  the  teeth  in  harmony  with  the  graceful  and 
beautiful  curve  of  the  normal  individual  arch.  This  muscular  pressure  is 
far  more  important  than  is  generally  recognized. 

Fig.  711  represents  the  teeth  of  a  child,  aged  eight  years,  where  the 
jaws  and  teeth  are  developing  normally.  It  will  be  noted  that  all  of  the 
permanent  lower  incisors  have  erupted  and  occupy  their  normal  positions 
in  the  line  of  occlusion,  each  occupying  its  full  mesio-distal  space  in  the 
arch,  compelling  the  lower  canines  to  occupy  positions  the  requisite  dis- 
tance apart.     Of  special  importance  is  the  influence  that  these  teeth 


OCCLUSION  697 

exercise  on  the  opposing  deciduous  canines  through  their  inclined  planes, 
each  blow  that  the  upper  canines  receive  from  the  lower  tending  to  widen 
the  upper  arch,  or  at  least  to  prevent  it  from  becoming  narrower  through 
the  pressure  of  the  lips. 

So  it  will  be  seen  that  normal  occlusion  of  the  teeth  is  maintained, 
first,  by  harmony  in  the  sizes  and  relations  of  the  dental  arches  through 
the  interdependence  and  mutual  support  of  the  occlusal  inclined  planes  of 
the  teeth;  and  secondly,  by  the  influence  of  the  muscles  labially,  buccally, 
and  lingually.  Of  course,  there  are  other  forces  in  the  normal  building 
and  maintaining  of  the  dental  apparatus,  such  as  structural  growth 
of  all  the  various  bones  and  tissues,  the  influence  of  co-related  organs, 
air  pressure  and  mental  influences,  all,  if  normal,  contributing  to  the 
perfect  balance  and  integrity  of  the  whole.  It  is  needless  to  say  that  such 
normality  would  only  be  possible  with  normal  balance  of  all  of  the 
forces  governing  growth  and  occlusion. 

Forces  Governing  Malocclusion. — In  beginning  the  consideration  of 
malocclusion,  let  us  remember  that  it  is  but  the  perversion  of  the  normal 
growth  and  development  of  the  denture — the  side-tracking,  as  it  were,  of 
nature  in  some  of  her  normal  processes  of  building,  and  we  would  repeat 
and  insist  that  before  anyone  can  intelligently  comprehend  malocclusion, 
he  must  have  as  a  basis  from  which  to  reason  in  determining  its  extent 
and  complexity,  a  thorough  knowledge  not  only  of  the  normal  growth 
and  development  of  the  dental  apparatus,  but  that  of  the  co-related 
organs  and  also  a  knowledge  of  their  functions  and  interdependence. 

We  know  that  every  case  has  a  simple  beginning  in  its  variation  from 
the  normal,  and  that  very  often  a  single  tooth,  from  slight  cause,  being 
deflected  from  the  normal,  may  and  usually  does  ultimately  involve 
others.  The  dividing  line,  then,  between  the  normal  and  the  abnormal 
in  the  beginning  is  very  slight,  but  always  clearly  defined,  so  the  normal 
in  occlusion  is  the  only  logical  basis  for  determining  the  variation  there- 
from and  the  extent  of  the  abnormal — malocclusion — and,  as  we  shall 
see,  the  same  forces  that  contribute  to  maintaining  the  teeth  in  their 
normal  positions  and  harmony  in  the  sizes  of  the  arches  are  equally 
powerful  when  perverted  in  maintaining  inharmony  in  the  sizes  and 
relations  of  the  arches  and  malocclusion  of  the  teeth. 

In  a  large  percentage  of  cases  of  malocclusion  the  arches  are  more 
or  less  contracted,  and  as  a  result  we  find  the  teeth  crowded  and  over- 
lapping. In  these  cases  the  lips  serve  as  constant  and  powerful  factors 
in  maintaining  this  condition,  usually  acting  with  equal  effect  on  both 
arches,  and  effectually  combating  any  influence  of  the  tongue  or  any 
inherent  tendency  on  the  part  of  nature  toward  self-correction.  In 
other  words,  the  arches,  narrowed  and  diminished  in  size,  are  so  main- 
tained by  force  from  the  lips,  equal  in  power  to  that  exerted  for  their 
normal  maintenance  when  of  normal  size  and  relation,  with  the  teeth 
in  normal  occlusion. 


698 


ORTHODONTIA 


Likewise  each  inclined  plane  of  the  cusps  once  out  of  hannonv  serves 
not  only  to  maintain  the  inhannony,  hut  to  increase  it,  upon  each  closure 
of  the  jaw. 

It  is  interesting  and  instructive  to  note  the  result  of  these  perverted 
forces  even  in  very  early  indications  of  malocclusion. 


Fir,.   712 


Fig.  712  illustrates  a  very  common  and  familiar  form  of  developing 
malocclusion.  The  case  is  that  of  a  child  where  the  four  lower  per- 
manent incisors  are  fully  erupted,  but  one  of  them  (the  left  lateral) 
has  been  deflected  lingually  (Fig.  713).  Being  thus  deprived  of  the 
wedging  and  retaining  influence  of  this  tooth,  the  pressure  of  the  li})s 


Fig.  713 


has  closed  the  space  and  diminished  the  size  of  the  lower  arch.  At  the 
same  time  pressure,  principally  from  the  lips  and  cheeks,  aided  by  the 
occlusal  planes  of  the  lower  deciduous  molars,  is  gradually  moulding 
the  upper  arch  to  conform  to  the  diminished  size  of  the  lower. 

It  will  thus  be  seen  how  effectually  the  malocclusion  will  be  main- 
tained and  how  hopeless  it  is  to  expect  nature  to  correct  this  deformity 


OCCLUSION  699 

unaided.     These  perverted  forces  are  traceable  in  all  cases  of  mal- 
occlusion. 

llecoo-nizing  the  j)(>tency  of  their  influence,  it  must  be  apparent  that 
cases  of  this  kind,  instead  of  being  self-corrective,  will  l)ecome  more  and 
more  complicated  as  time  goes  on  and  as  each  succeeding  permanent 
tooth  erupts.  How  absurd  and  unfortunate,  then,  is  the  common  daily 
advice  of  many  dentists  to  anxious  parents  to  "let  the  teeth  alone  and 
nature  will  correct  them  unaided." 

In  all  such  cases  the  position  of  the  erupting  permanent  lower  incisors 
should  be  guarded  with  zealous  care,  placed  in  correct  positions,  and 
maintained  therein,  that  they  may,  through  occlusion,  assist  in  directing 
the  teeth  of  the  opposing  arch  into  normal  positions  and  be  compelled 
to  fulfil  their  important  part  in  the  full  normal  development  of  the 
alveolar  process.  This  is  the  golden  opportunity  for  beginning  intelli- 
gent interference  for  the  prevention  of  what  might  otherwise  become 
complicated  cases  of  malocclusion.  This  also  applies  with  equal  force 
to  any  other  lower  tooth  that  may  erupt  into  abnormal  position,  especially 
the  lower  first  molars.  If  the  lower  teeth  erupt  in  their  normal  positions 
either  naturally  or  through  proper  treatment,  the  upper  teeth  will 
usually  take  their  normal  positions. 

For  the  reason  previously  stated,  if  the  teeth  of  the  lower  arch  be 
permitted  to  remain  in  malposition  even  to  the  slightest  overlapping  of 
one  or  more  of  the  incisors  or  canines,  the  arch  will  be  diminished  in 
size  just  to  that  extent,  and  as  a  result  of  pressure  of  the  lips  there  will 
be  a  corresponding  contraction  in  the  upper  arch  and  some  form  of 
bunching  of  the  teeth,  especially  in  Class  I. 

The  influence  of  the  lips  in  modifying  the  form  of  the  dental  arches 
is  an  interesting  study,  and  almost  every  case  of  malocclusion  offers 
some  noticeable  and  varying  manifestation  of  it.  Indeed,  the  forces 
from  perverted  lip  and  cheek  function  are  far  more  potent  and  frequent 
causes  of  malocclusion  than  has  heretofore  been  recognized.  This 
phase  of  this  question  will  be  further  discussed  under  the  sections  on 
Etiology  of  Malocclusion  and  Treatment. 

The  result  of  pressure  from  the  tongue  in  exerting  force  upon  the 
inside  of  the  arches  is  also  a  factor,  we  are  convinced,  of  great  impor- 
tance in  determining  the  form  of  the  arches  and  the  positions  of  the 
individual  teeth.  That  when  normal  in  s^e,  tone,  and  function,  it 
exercises  a  gentle  force  upon  the  inside  of  the  arch,  which  is  in  perfect 
harmony  with  the  force  exerted  by  the  muscles  upon  the  outside  in 
maintaining  the  correct  balance  in  muscular  pressure  upon  the  teeth, 
is  well  known,  but  when  these  forces  are  perverted,  through  abnormal 
size  or  function  of  the  tongue,  the  result  is  most  noticeable  and  character- 
istic in  the  malpositions  into  which  the  teeth  are  forced.  This  subject 
will  also  be  further  discussed  in  the  section  on  Etiology. 

The  transferring  of  force  from  air  pressure  from  the  floor  of  the  nose 


700 


ORTHODONTIA 


in  nasal  breathing,  to  the  vauU  of  tlie  arch  in  month  hreathinff,  is  doubt- 
less also  a  factor  of  much  importance  in  the  development  and  maintaining 
of  malocclusion. 

When  the  teeth  are  in  normal  occlusion  the  influence  of  the  inclined 
occlusal  planes  and  the  relations  of  the  crowns  and  roots  of  the  teeth 
are  such  that  the  great  weight  or  force  that  each  must  bear  in  occlusion 
is  in  perfect  balance  with  a  line  of  axis  common  to  l)oth  dental  arches, 
as  shown  in  Fie.  706,  this  line  of  axis  being  such  that  the  force  does 
not  tend  to  displace  either  crowns  or  roots  of  the  teeth  either  lingually 


Fics.  714 


LytUill 


Groove  [hiatus  »emilunariH\ 
'  li'ddiuq  to  iiijitiidibuliiin 
•Middle  turbinated  bout 

Middle  meatus 

1. 1  ntrum  of  Highmore 

•Inferior  meatus 

Inferior  turbinated  bone 


Buccal  cavity 

Space  betiveai  cheek  and  gum 

Molar  tooth,  upper  jmv 


•Root  of  molar  tooth 


Inferior  dental  nerve 


or  bucally,  mesially  or  distally,  but  instead  is  such  as  best  to  stimulate 
the  normal  growth  of  the  jaws,  palate,  and  nasal  bones,  and  probably 
all  other  bones  and  tissues  of  the  face,  and  best  to  maintain  their  normal 
size  and  harmony  of  relations.  But  when  the  line  of  stress  is  changed 
from  the  normal  axis  to  one  that  is  abnormal,  as  when  all  the  upper 
buccal  teeth  are  in  lingual  occlusion,  the  result  is  to  disturb  the  balance 
greatly,  and  force  the  roots  and  crowns  of  the  upper  teeth  lingually 


CLASSIFICATION  OF  MALOCCLUSION 


701 


ami  those  of  the  lower  huccally.  How  powerful  is  the  force  when  so 
perverted  is  shown  in  the  remarkable  case  illustrated  in  Fig.  708. 

By  studying  this  picture  in  comparison  with  the  one  shown  in  Fig. 
714,  it  is  easy  to  realize  how  greatly  the  normal  development  of  the 
vault  of  the  arch  and  the  bones  of  the  nose  has  been  interfered  with  by 
this  perversion  of  force. 

Another  lesson  is  also  here  impressed,  namely,  how  interdependent 
are  the  work  of  the  rhinologist  and  that  of  the  orthodontist,  and  vice 
versa,  and  how  utterly  useless  for  either  to  hope  for  success  in  the  treat- 
ment of  many  of  these  cases  without  the  assistance  of  the  other,  and 
how  important  that  both  should  cooperate  as  early  as  possible  in  their 
work  of  establishing  the  normal  forces  of  growth  and  development. 


CLASSIFICATION    OF  MALOCCLUSION 


Nomenclature. — All  teeth  found  out  of  harmony  with  the  line  of 
occlusion  may  be  said  to  occupy  positions  of  malocclusion,  and  each 
tooth  may  occupy  any  of  seven  malpositions  or  their  various  deviations 
and  combinations. 


The  malpositions  of  teeth  consist  principally  in  the  variation  of  the 
positions  of  their  crowns  from  the  normal,  with  usually  little  displace- 
ment of  the  apices  of  their  roots,  so  that  they  incline  at  an  angle  more 
or  less  oblique  from  the  normal.  In  some  instances,  however,  there 
is  some  displacement  of  the  apices  as  well  as  of  the  crowns,  they  having 


702  ORTHODONTIA 

cither  developed  in  malpositions,  or,  as  in  most  instances,  having!;  heen 
forced  from  their  normal  positions  \)y  mechanical  influences,  or  the 
eruption  of  more  powerful  teetii  in  juxtaposition,  as,  for  example,  the 
crowding  lingually  of  the  lateral  incisors  by  the  development  and  eruption 
of  the  canines,  as  in  Fig.  715.  Yet  even  in  such  cases  the  displacement 
is  not  so  great  as  appears,  the  malpositions  of  the  crowns  magnifying 
this  appearance. 

A  definite  nomenclature  is  as  necessary  in  orthodontia  as  in  anatomy. 
The  vagueness  of  descriptive  terms  often  used  renders  them  very 
inadecjuate.  The  terms  for  descril)ing  the  various  malpositions  of  teeth 
should  be  so  precise  as  to  convey  at  once  a  clear  idea  of  the  nature  of 
the  malocclusion  to  Ije  corrected.  The  author  therefore  suggests  the 
following,  which,  while  perhaps  not  perfect,  still  seems  to  be  a  great 
improvement  on  common  usage. 

For  example,  a  tooth  outside  the  line  of  occlusion  may  be  said  to  be 
in  buccal  or  labial  occlusion;  when  inside  this  line,  in  lingual  occlusion; 
if  farther  forward,  or  mesial,  than  normal,  in  mesial  occlusion;  if  in  the 
opposite  direction,  in  distal  occlusion;  if  turned  on  its  axis  it  would  be 
in  torto-occlusion.  Teeth  not  sufficiently  elevated  in  their  sockets  would 
be  in  infra-occlusion,  and  those  that  occupy  positions  of  too  great  eleva- 
tion, in  supra-occlusion.  These  terms  used  singly  or  in  combination  will 
accurately  describe  the  malpositions  of  any  tooth  or  teeth  in  any  case  of 
maloccusion,  from  the  simplest  to  the  most  complex,  and  used  in  con- 
nection with  the  writer's  classification,  make  possible  the  conveying  of 
a  very  complete  picture  of  any  given  case  of  malocclusion  in  very  few 
words. 

Although  the  number  of  cases  of  malocclusion  is  limitless,  in  no  two 
do  we  find  the  arrangement  of  the  teeth  alike,  even  in  those  strikingly 
similar  cases  of  Division  1,  Class  II. 

Yet,  notwithstanding  this  endless  variation,  which  has  led  to  endless 
confusion  in  diagnosis  and  treatment  among  the  old  school  writers 
and  practitioners,  as  we  shall  see,  all  cases  of  malocclusion  fall  naturally 
into  a  very  few  distinct  and  easily  recognized  groups,  or  three  great  classes, 
with  their  divisions  and  subdivisions,  and  when  so  classified  the  extent 
of  the  variation  from  the  normal  in  each  case  is  easily  comprehended 
and  the  recjuirements  of  treatment  made  manifest. 

The  classification  of  malocclusion  is  based  on  the  mesio-distal  relations 
of  the  teeth,  dental  arches,  and  jaws,  which  depend,  primarily,  in  the 
permanent  denture,  upon  the  positions  mesio-distally  assumed  by  the 
first  permanent  molars  xyn  their  erupting  and  locking.  Hence  in  diag- 
nosing cases  of  malocclusion  we  must  consider,  first,  the  mesio-distal 
relations  of  the  jaws  and  dental  arches,  as  indicated  by  the  relation  of 
the  lower  first  molars  with  the  upper  first  molars — the  keys  to  occlusion, 
and  secondly,  the  positions  of  the  individual  teeth,  carefully  noting  their 
relations  to  the  line  of  occlusion. 


CLASSIFICATION  OF  MALOCCLUSION 


703 


Class  I,  illustrated  by  Figs.  710  and  717,  is  characterized  by  normal 
mesio-distal  relations  of  the  jaws  and  dental  arches,  and  normal  locking 
of  the  first  molars;  that  is,  mesio-distally.  One  or  even  all  of  the  molars 
may  be  in  buccal  or  lingual  occlusion,  but  this  is  only  an  incident  and 
may  occur  in  any  class,  and  is  not  constant  in,  nor  a  characteristic 
peculiar  to,  any  particular  class. 

In  this  class  the  malocclusion  ranges  from  the  slightest  overlapping 
of  a  single  tooth  to  the  most  complex  derangement,  involving  the  posi- 
tions of  all  of  the  teeth  in  both  arches,  as  in  Fig.  872.  In  the  average 
case  (Figs.  716  and  717),  however,  the  arches  are  more  or  less  shortened 
and  reduced  in  size,  with  a  corresponding  crowding  of  the  teeth. 


Fig.  716 


Fig.  717 


Class  II. — ^^^len  the  lower  jaw  is  distal  to  its  normal  relation  with 
the  upper  jaw,  and  the  lower  first  molars  lock  distally  to  normal,  it  must 
necessarily  follow  that  every  succeeding  permanent  tooth  to  erupt  must 
also  occlude  abnormally,  all  the  lower  teeth  being  forced  into  positions 
of  distal  occlusion,  causing  retrusion  and  more  or  less  underdevelop- 
ment, of  the  entire  lower  jaw.^  This  condition  of  distal  occlusion  is  the 
determining  characteristic  of  Class  II. 

Of  this  class  there  are  two  divisions,  each  having  a  subdivision : 
Division  1  is  characterized  by  distal  occlusion  of  both  lateral  halves 
of  the  lower  dental  arch,   a  narrowed  upper  arch,  protruding  upper 

^  In  this  classification  the  writer  has  selected  typical  cases  representing  the  first 
permanent  molars  in  distal  or  mesial  occlusion  (in  Classes  II  or  III)  the  full  width 
of  the  cusp,  but  it  should  be  remembered  that  the  complete  distal  or  mesial  locking 
of  the  molars  is  unnecessary  to  the  correct  placing  of  cases  in  their  proper  classes, 
but  the  mal-locking  of  the  inclined  planes  of  the  cusps  must  be  such  as  ultimately 
will  lead  to  their  full  mesial  or  distal  locking.     See  also  pages  687  and  688. 


704  ORTHODONTIA 

iiK'isors,  .short  and  j)i-aftifally  fuiic-tionles.s  upper  lip,  Iciifftlieiicd  lower 
incisors,    and    thickened   lower   lip    which    rests  cushion-like  between 

Fig.  718 


the  upper  and  lower  incisors,  increasing  the  protrusion  of  the  former 
and  the  retrusion  of  the  latter.     A  like  condition  is  sometimes  foinid  in 


Fig.  719 


younger  patients  who  have  as  yet  erupted  only  their  deciduous  teeth.     It 
seems  probable  that  cases  of    malocclusion  belonging  to  this  division 


CLASSIFICATION  OF  MALOCCLUSION 


705 


of  this  class  are  caused  by  some  form  of  nasal  obstruction  necessitating 
mouth-breathinti;,  which  is  usually  an  accompaniment — probably  always 
in  the  early  stages. 

There  is  great  similarity  in  the  malocclusion  in  cases  belonging  to 
this  division,  and  the  disturbance  in  the  facial  lines  is  also  characteristic 
and  pronounced.  The  malocclusion  typical  of  this  division  of  this  class 
is  shown  in  Fig.  718. 


Fig.  720 


Subdivision,  Division  1,  has  the  same  characteristics,  differing  only 
in  that  the  distal  occlusion  is  unilateral,  as  shown  in  Fig.  719.  This 
condition  may  also  be  found  in  the  deciduous  denture. 

Division  2  is  characterized  also  by  distal  occlusion  of  both  lateral 
halves  of  the  dental  arches,  but  by  retrusion  instead  of  protrusion  of  the 
upper  incisors.  In  this  division  there  are  no  complications  from  patho- 
logical conditions  of  the  nasal  passages,  hence  the  mouth  is  kept  closed 
the  normal  amount  of  time,  and  the  lips  perform  their  normal  functions, 
which  causes  the  repression  of  the  upper  incisors  until  they  come  in 
45 


700 


ORTIIODOXTIA 


contact  with  the  lower  incisor.s,  causiiif^  hunchniff  and  ()v«.Thi{)piii^f 
of  the  upper  incisors  and  canines,  as  shown  in  Fig.  720. 

Siilxlivision,  Division  2,  has  tlie  same  characteristics  as  Division  2, 
differing  chiefly  in  that  the  nioUir  occlusion  is  unilaterally  distal,  as 
shown  in  Fig.  721. 

The  marring  efVect  on  the  facial  lines  of  the  malocclusion  of  Division  2 
and  its  subdivision  is  both  marked  and  characteristic,  but  very  different 
from  that  of  Division  1  and  its  subdivision. 

Ci.Ass  III  is  characterized  by  the  locking  mesially  to  their  normal 
relations  of  the  inclined  planes  of  tiie  lower  first  molars  in  both  lateral 
halves  of  the  dental  arches.    This  is  but  slight  in  the  beginning,  but  as 


Fig.  721 


these  cases  are  always  progressive,  the  mesial  ocdusicMi  may  progress 
to  include  the  full  width  of  one  or  e\en  two  cusps,  as  in  the  extreme 
case  shown  in  Fig.  722.  In  cases  belonging  to  this  class,  the  arrange- 
ment of  the  teeth  in  their  respective  arches  varies  greatly  from  tjuite 
even  and  regular  alignment  to  considerable  crowding,  especially  in 
the  upper  arch.  There  is  usually  a  decided  lingual  inclination  of  the 
lower  incisors  and  canines,  which  becomes  more  and  more  pronounced 
as  the  case  progresses,  and  which  is  due  to  the  pressure  of  the  lower 
lip  in  the  effort  to  dost'  the  mouth. 

In  addition  to  the  inharmony  in  the  iclations  of  (lie  jaws,  there  is 
usually  inharmony  also  in  the  sizes  of  the  two  dental  arches,  especially 
in  fully  developed  cases,  due  to  the  asynnnetrical  development  of  the 


CLASSIFICATION  OF  MALOCCLUSION 


707 


Fig.  722 


Fig.  723 


708  OliTIIODOATIA 

maxillary  hones,  the  angle  of  the  lower  jaw  heinj^;  more  ohtuse  than 
normal,  hnt  it  may  also  be  the  result  of  overdeveloj^ment  in  the  body 
of  the  jaw.  Other  characteristics  met  witii  in  this  class  are  considered 
in  tile  section  on  Treatment,  page  S()4. 

In  all  cases  l)elonging  to  this  class  the  marring  of  the  facial  lines  is 
most  noticeable,  and  in  direct  proportion  to  the  extent  of  malocclusion. 

Subdivision,  Class  III. — This  subdivision  differs  from  the  division 
only  in  degree,  one  of  the  lateral  halves  of  the  arch  only  being  in  mesial 
occlusion,  the  other  being  normal,  as  shown  in  Fig.  72;},  the  arches 
crossing  in  the  region  of  the  incisors. 

That  all  cases  of  malocclusion  met  with  will  be  found  to  be  embraced 
in  the  above  classification  is  more  than  probable.  There  still  remains, 
however,  one  possible  class — viz.,  where  one  of  the  lateral  halves  of  the 
lower  arch  is  in  mesial  occlusion  while  the  other  is  in  distal  occlusion; 
l)ut  cases  having  these  characteristics  are  so  very  rare  that  no  further 
reference  to  them  is  necessary,  the  writer  ha^ing  never  seen  but  two 
or  three  cases. 

In  diagnosticating  cases  according  to  the  above  classification,  it  will  be 
seen  that  the  occlusion  of  each  of  the  lateral  halves  of  the  arches  is 
important,  and  must  be  considered  separately  and  with  et[ual  and  care- 
ful attention,  alw-ays  beginning  with  the  first  permanent  molars.  In 
cases  of  malocclusion  of  very  young  children  who  have  only  their  decidu- 
ous dentures,  diagnosis  should  begin  with  the  second  deciduous  molars. 

In  developing  cases  of  the  second  and  third  classes  when  the  lower 
jaw  may  be  in  a  state  of  transition  and  has  not  attained  to  distal  or 
mesial  occlusion  the  full  width  of  a  cusp  on  one  or  both  sides,  the  l)eginner 
may  be  a  little  puzzled  as  to  the  proper  classification;  but  upon  careful 
inspection  and  close  study  a  majority  of  the  inclined  planes  will  be  found 
to  favor  one  particular  class,  the  co-relation  of  the  first  molars  being, 
of  course,  the  most  important  factor. 

The  loss  of  a  tooth  or  teeth  by  extraction  is  followed  by  such  marked 
changes  in  the  positions  of  the  remaining  teeth  that  diagnosis  is  some- 
times greatly  complicated.  Therefore,  great  care  and  judgment  should 
be  exercised,  making  allowance  for  the  tipping  of  teeth  and  other  changes 
which  have  taken  place  as  a  result  of  extraction,  in  order  to  determine 
their  original  positions.  This  point  being  decided,  the  correct  diag- 
nosis according  to  the  above  classification  becomes  easy. 

A  brief  recapitulation  of  the  classification  is  here  given  for  convenience 
of  study  and  for  ready  reference : 

Class  I. — Arches  in  normal  mesio-distal  relations,  with  malocclusion 
of  anterior  teeth. 

Class.  II. — Lower  arch  distal  to  normal  in  its  relation  to  upper  arch. 
Division  1. — Bilaterally  distal,  protruding  upper  incisors.     Usually 
mouth-breathers. 
Subdivision. — Unilaterally    distal,    protruding    upper    incisors. 
Usually  mouth-breathers. 


FACIAL  ART  709 

Division  2. — Bilaterally  distal,  rotrudinpj  upper  incisors.     Normal 
breathers. 
Subdivision. — Unilaterally  distal,  retruding  upper  incisors.    Nor- 
mal breathers. 
Class   III, — Lower  arch  mesial  to  normal  in  its  relation  to  upper 
arch. 
Division. — Bilaterally  mesial. 

Subdivision. — Unilaterally  mesial. 
Out  of  several  thousand  cases  of  malocclusion  examined,  the  pro- 
portion per  thousand  belonging  to  each  class  was  as  follows : 

Class  I 692 

Class  II. 

Division  1 90 

Subdivision 34 

Division  2 42 

Subdivision 100 

Class  III. 

Division 34 

Subdivision 8 

1000 


FACIAL  ART 

Art,  as  related  to  the  human  face,  must  ever  have  an  important 
bearing  on  the  study  of  orthodontia,  for  the  mouth  is  a  most  potent 
factor  in  making  or  marring  the  beauty  and  character  of  the  face,  and 
the  positions  of  the  teeth  are  to  a  very  large  extent  responsible  for  the 
proper  form  and  beauty — or  the  lack  of  it — of  the  mouth.  No  one 
can  be  beautiful  unless  the  mouth  is  in  harmony  with  all  the  other 
features,  and  no  one  afflicted  with  malocclusion  can  have  a  mouth  that 
is  thus  in  harmony. 

The  duties  of  the  orthodontist  force  tipon  him  great  responsibilities, 
and  there  is  no  subject  in  which  the  student  of  orthodontia  should  be 
more  keenly  interested  nor  better  informed  than  in  art  generally,  and 
especially  as  it  relates  to  the  human  face;  for  each  of  his  efforts,  whether 
he  realizes  it  or  not,  makes  for  beauty  or  ugliness,  for  harmony  or  inhar- 
mony,  for  perfection  or  deformity. 

But  in  order  that  our  efforts  may  be  intelligently  directed  toward 
the  ideal,  there  must  be  some  grand  principle  as  a  basis  from  which  to 
reason,  or  we  must  be  but  gropers  in  the  dark,  experimenters,  producing 
results  which  may  cause  embarrassment  or  even  bitter  regret. 

Though  human  faces  are  all  greatly  alike,  yet  all  differ.  Lines  and 
rules  for  their  measurement  have  ever  been  sought  by  artists,  and  many 
have  been  the  plans  for  determining  some  basic  line  or  principle  from 
which  to  detect  variations  from  the  normal,  but  no  line,  no  measurement, 
admits  of  anything  nearly  like  universal  application. 


710  ORTIIODOXTIA 

The  hcautifiil  face  of  tlie  Apollo  Belvedere  has  very  largely  been 
used  as  a  ^uide  toward  the  ideal  and  from  which  to  judi,a*  variations, 
hut  this  has  been  found  to  he  itnpractical)le  and  misleading;  and  this  is 
easily  understood  when  we  renieniher  that  the  Apollo  face  represents 
the  type  of  the  ideal  (Irecian  beauty,  while  now  the  (ireek  type  is 
rarely  seen,  and  in  its  place  we  have,  especially  in  America,  many 
tvpes  and  the  greatest  number  of  variations  (jf  each  type,  each  face  being 
a  law  unto  itself,  and  })resenting  demands  as  to  measurements  and 
proportions  wholly  peculiar  to  itself. 

According  to  one  of  our  foremost  teachers  of  art,  Mr.  E.  H.  Wuerpel, 
there  /.s-  a  principle  for  our  use  which  is  e(|ually  applicable  to  all  faces — 
viz.,  the  principle  of  balance,  of  symmetry.  We  must  be  able  to  detect 
whether  the  features — that  is,  the  forehead,  the  nose,  the  chin,  the  lip.s — 
of  each  individual  face  balance,  harmonize,  or  whether  they  are  out  of 
balance,  out  of  harmony,  and  especially  whether  the  mouth  is  in  harmo- 
nious relations  with  the  other  features,  and,  if  it  is  not,  what  is  necessary 
to  place  it  in  l)alance. 

The  faculty  of  determining  the  propter  balance  of  the  features  is  a 
difficult  one  to  attain.  The  authority  above  referred  to  says  that  only 
one  in  two  or  three  hundred  art  students  ever  succeed  in  mastering  it, 
and  these  only  after  much  oi^servation  and  practice  in  .sketching  and 
modelling  faces. 

Unpromising  as  this  .seems,  it  is  doubtless  correct,  yet  we  have  a  rule 
for  determining  the  best  balance  of  the  features,  or  at  least  the  best 
balance  of  the  mouth  with  the  rest  of  the  features,  that  artists  probably 
know  nothing  of,  and  one  that  for  the  orthodontist  is  more  unvarying  and 
more  reliable  than  even  the  judgment  of  the  favored  few — a  rule  so 
invariable  and  with  so  few  exceptions  that  we  may  consider  it  a  law, 
and  if  it  be  not  applicable  in  all  cases,  the  exceptions  will  be  so  very  rare 
that  they  are  hardly  worth  considering.  It  is,  furthermore,  a  rule  so 
plain  and  so  simple  that  all  can  understand  and  apply  it.  It  is  that 
the  best  balance,  the  best  harmony,  the  best  proportions  of  the  mouth, 
in  its  relations  to  the  other  features,  require  that  there  shall  be  the  full 
complement  of  teeth,  and  that  each  tooth  shall  be  made  to  occupy  its 
normal  position  in  the  architectural  line  of  occlusion  according  to  each 
individual  type — normal  occlusion. 

Fig.  724  shows  the  face  of  Apollo.  The  face  is  a  study  of  .symmetry 
and  harmony  of  proportion,  and  such  lines  are  wholly  incompatible 
with  teeth  in  malocclusion  or  with  less  than  the  full  complement  of 
teeth. 

Fig.  725  shows  another  face,  which  is  also  one  of  much  l)eauty  and 
fine  proportions.  It  is  also  somewhat  of  a  Greek  type,  and  the  lower 
half  of  the  face  shows  lines  which  could  only  have  been  moulded  over 
teeth  normal  in  number,  type,  size,  and  position,  and. accompanied  by 
normal  conditions  of  development  and  nasal  function. 


711 


Fig.  725 


Fig.  726 


Fig.  726^  shows  a  face  that  is  a  blending  of  the  Greek  and  Roman 
types,  and  it  also  is  in  fine  balance,  although  very  different  from  that  of 


William  Whipple. 


712 


ORTIIODOSTIA 


Aj)()llo.  'V\\v  t'caturcs  arc  lar<;e  and  j)r()iiiiiient  and  tlio  head  is  larojr, 
l)ut  thrrc  is  a  harmony  of  size,  rehition,  and  j)r()j)ortion  that  forms  a 
most  pleasini;'  whole.     The  faee,  \vhil(>  in  fine  lialance,  is  perhaps  not 


Fig.  727 


Fig.  7_'8 


Fig.  729 


beautiful  from  a  physical  standpoint,  but  it  is  more.  It  is  beautiful  from 
an  intellectual  standpoint,  possessing  strength,  nobility,  majesty — that, 
in  the  writer's  opinion,  is  lamentably  lacking  in  the  Apollo  face. 


FACIAL  ART  713 

Fiir.s.  727  and  72S,  and  Fiir.  72!)  show  tlu-  laces  of  two  norinall\  devel- 
opinf^  children,  although  it  will  he  observed  that  they  are  of  strikingly 
different  types.    The  j)roportions  of  the  faces,  the  balance  of  the  features, 


and  the  harmonious  lines  of  the  mouths  tell  as  truthfully  that  they  are 
being  moulded  over  dental  arches  developing  normally,  with  teeth  in 
normal  occlusion,  as  the  models  of  the  teeth  themselves,  shown  in  Figs. 
730  and  731. 


Fig.  731 


In  these  cases  nature  has  been  able  to  work  unhampered  by  detri- 
mental pathological  conditions,  which  is  apparent  in  the  results. 


714 


ORTI/ODOXTIA 


Of  course,  it  must  ho  understood  tliat  changes  in  the  contour  of  these 
young  faces  nnist  take  place  with  greater  development.  The  noses  and 
chins  will  develop  and  become  more  prominent,  and  after  the  eruption 
of  the  j)ermanent  canines  there  will  he  more  of  an  acute  angle  between 
the  nose  and  the  upj)er  lip,  esj)ecially  in  the  face  shown  in  Fig.  729. 
But  the  point  we  would  emphasize  is  the  normal  development  and  con- 
se(juent  normal  balance  and  symmetry  of  these  faces,  and  if  we  will 
notice  any  child  that  is  developing  normally,  or  any  person  who  has 
reached  maturity  with  the  teeth  in  normal  occlusion,  we  will  find  an  equal 
harmony  of  balance  of  the  mouth  with  the  other  features.  Dr.  R.  Anema 
has  well  said  that  "probably  the  greatest  reason  why  there  is  such  uni- 
formity of  harmony  in  the  facial  lines  of  young  children  is  that  their 
teeth  (the  deciduous  teeth)  are  so  free  from  malocclusion." 


Fin.   732 


The  writer  would  not  be  understood  as  implying  that  every  face  with 
lines  and  features  in  harmony  of  balance  must  necessarily  be  beautiful, 
nor  even  that  placing  maloccluded  teeth  in  normal  occlusion  will  always 
put  the  whole  face  in  harmony  of  balance.  There  may  be  defects  in  the 
face,  as  lack  of  development  of  the  nose  or  chin,  or  une(jual  development 
of  the  malar  bones  or  of  any  of  the  bones  of  the  face,  or  defects  in  the 
eyes  or  ears,  or  in  the  shape  of  the  head,  which,  of  course,  could  not  l)e 
remedied  by  the  correction  of  malocclusion  alone,  but  the  best  harmony  of 
such  faces,  or  of  any  face,  is  only  possible  when  the  teeth  are  in  normal 
occlusion.  Alalocclusion,  or  the  loss  of  teeth  by  extraction  or  non- 
eruption,  or  a  combination  of  these  two  causes,  is  responsilde  for  far 
more  faces  out  of  balance  and  out  of  harmony  than  any  other  cause 
or  combination  of  cau.ses,  and  this  inharmony  and  lack  of  balance  of 
the  mouth  exists  just  in  proportion  to  the  degree  of  malocclusion. 

For  a  true  understanding  of  what  is  meant  by  harmony  of  proportion 
and  balance  of  faces,  a  careful  study  must  be  made  of  faces  that  are  out 
of  balance  as  well  as  of  those  that  are  in  balance. 

The  effect  on  the  facial  lines  of  the  varying  forms  of  malocclusion 
found  in  the  three  different  classes  varies  not  only  with  the  degree  of 
malocclusion,  but  also  with  the  individual  type  of  face,  yet,  notwith- 


FACIAL  ART 


711 


.staiuliMo'  this,  the  t_v])o  of  facial  defonnity  j^iroducecl  l)y  oach  separate 
class  of  inalocclusioii  is  so  constant  that,  after  some  practice,  the  close 
observer  may  classify  with  nnich  accuracy  the  malocclusion  of  the 
people  he  observes  without  an  actual  examination  of  their  teeth.  This  is 
also  true  in  the  case  of  extraction,  or  the  loss  or  lack  of  teeth  from  any 
cause. 


Fig.  733 


In  Class  I,  the  chin  and  nose  will  usually  be  found  in  relatively  nor- 
mal balance' with  the  forehead  and  general  contour  of  the  face,  and 
the  lines  of  abnormality  confined  more  or  less  to  the  mouth  itself. 

Fig.  732  shows  such  a  case  in  the  profile  of  a  boy,  aged  fourteen  years, 
and  \he  lack  of  balance  in  the  flat  and  sunken  lines  of  the  mouth 
clearly  indicates  diminished  sizes  of  the  dental  arches.  This  lack  of 
normal  contour  of  the  mouth  will  be  more  impressive  when  it  is  remem- 
bered that  at  this  age  a  boy's  mouth  should  be  relatively  more  prominent 
than  that  of  a  man,  for  the  reason  that  his  face  has  not  yet  reached  its 
full  grow^th,  while  the  teeth  are  full-sized  at  eruption. 

Fio-s.  716  and  717  show  the  reason  for  this  lack  of  normal  contour, 
namely,  lack  in  the  development  of  the  alveolar  process  and  pronounced 
crowdino;  of  the  teeth. 


710 


ORTHODOSriA 


Tlie  correctness  of  our  rule  is  veritietl  in  the  corrected  occlusion, 
shown  in  Fig.  884,  and  in  the  restored  facial  lines  in  Fig.  733. 

Fig.  734  shows  the  profile  of  a  young  girl  whose  malocclusion  belongs 
to  Division  1.  Class  II,  and  the  lines  of  inharnionv  shown  in  this  face 
are  characteristic  of  all  cases  of  this  division  of  this  class  of  malocclusion, 
and  also  of  the  subdivision. 

In  cases  belonging  to  Class  I,  as  we  have  seen,  the  mouth  is  the 
onlv  feature  gready  out  of  harmony;  but  in  these  cases  the  nose,  the 
mouth,  and  the  chin  must  be  greatly  out  of  balance,  both  with  each 
other  and  with  the  general  contour  of  the  face,  due  to  the  type  of 
malocclusion  of  this  class,  as  illustrated  in  Fig.  718. 


FtG.  7:« 


Fk;.  735 


To  attempt  to  restore  balance  and  harmony  of  proportion  to  this 
face  by  placing  all  the  teeth  in  normal  occlusion  is  perhaps  to  seem  to 
put  our  rule  to  a  severe  test,  but  its  correctness  is  shown  in  the  result 
on  the  facial  lines  in  Fig.  735,  and  while  the  face  may  still  not  be  beau- 
tiful, we  believe  that  by  no  other  means  could  it  have  been  placed  in  so 
nearly  normal  balance  or  harmony. 

It  will  be  observed  that  this  type  of  face  ditt'ers  greatly  from  the 
straight-line  Apollo  face;  yet  in  cases  of  malocclusion  both  types  of 
face  are  equally  susceptible  of  being  restored  to  the  correct  balance 
normal  to  each,  and  both  by  the  same  method — namely,  the  establish- 
ment of  normal  occlusion. 

Since  in  this  case  there  have  been  established  normal  relations  of  the 
muscles  and  of  the  inclined  planes  of  the  teeth,  and  normal  nasal 
respiration  has  also  been  established,  the  further  development  of  this  face 


FACIAL  ART 


717 


will  be  toward  the  normal — toward  harmony — instead  of  in  the  opposite 
direction,  as  had  been  the  case  since  the  day  the  nasal  trouble  first 
caused  mouth-breathing,  or  since  the  first  abnormal  locking  of  the 
inclined  planes  of  the  first  permanent  molars. 

The  disturbance  of  Imlance  of  the  facial  lines  in  the  subdivision  of 
this  division  differs,  usually,  only  in  degree. 

Fig.  73()  shows  the  profile  of  a  young  man's  face  which  is  fairly 
typical  of  the  lack  of  balance  of  facial  lines  due  to  malocclusion  of  the 
second  division  of  Class  11.     The  malocclusion  is  shown  in  Fig.  928. 


Fig.   73(5 


I'k;.   737 


The  head  is  large  and  well  shaped,  and  the  forehead  and  nose 
strong  and  in  good  balance,  but  there  is  a  weakness  about  the  mouth 
and  chin  that  is  greatly  out  of  keeping  with  the  general  contour  of  the 
head. 

We  have  but  to  study  the  malocclusion  to  readily  detect  the  cause, 
namely,  distal  occlusion  with  normal  nasal  and  lip  functions  which  have 
pushed  the  upper  incisors  back  to  occlude  with  the  lower  incisors  and 
caused  a  crowding  and  overlapping  in  the  upper  canine  region. 

Again,  the  rule  was  applied  and  each  tooth  made  to  occupy  its  normal 
position  in  the  line  of  occlusion,  with  the  most  gratifying  result  on 
the  facial  lines,  shown  in  Fig.  737.  Those  weak  lines  of  inharmony 
have  been  changed  to  others  of  strength  and  harmony  of  balance,  in 
contrast  to  the  lines  that  must  have  followed  had  extraction  been 
resorted  to  as  the  plan  of  treatment. 

The  restored  occlusion  is  shown  in  Fig.  929. 

The  disfiguring  effect  on  the  face  caused  by  malocclusion  of  the 
subdivision  of  this  division  of  Class  II  are  similar  to  those  just  shown 
in  the  full  division. 


718 


OUTllODOSTIA 


Fig.  73S  .shows  the  profile  of  a  girl,  aged  thirteen,  whose  facial  lines 
were  thrown  out  of  balanee  by  reason  of  malocclusion  of  Class  111, 
as  shown  in  Fig.  94.S. 

A  very  superficial  study  of  the  malocclusion  is  sufficient  to  show  us 
the  reason  for  the  flat  upper  lip  and  unnatural  prominence  and  heavi- 
ness of  the  chin  and  lower  lij). 

The  applying  of  our  rule,  or  the  establishing  of  normal  occlusion, 
produced  the  result  in  facial  lines  shown  in  F'ig.  730,  and  in  occlusion 
shown  in  Fig.  1)49. 

The  subdivision  of  Cla.ss  HI  is  characterized  by  the  same  type  of 
facial  disturbance  as  the  division. 


Fig.   739 


Thus  far  we  have  considered  the  marring  effect  on  the  facial  lines 
resulting  from  malocclusion  when  the  normal  number  of  teetli  is 
present;  but  there  is  anotherpha.se  of  malocclusion,  the  effects  of  which 
are  very  pronounced  in  the  disturbance  of  the  facial  balance,  namely, 
the  all  too  common  loss  of  teeth  from  nuitilation  by  extraction,  or  their 
occasional  non-development,  or  non-eruption,  and  the  (listurl)ance  in 
facial  balance  will  i)e  in  exact  j)r()})orti()n  to  the  extent  of  the  loss  or 
lack  of  teeth. 

The  loss  of  even  a  single  tooth  not  only  j)roduces  great  inharmony 
of  occlusion,  but  equal  inharmony  in  the  facial  lines.  Fig.  740  shows 
the  profile  of  a  young  girl  whose  upper  right  lateral  incisor  failed  to 
develop,  as  was  revealed  by  the  .r-rays,  and  the  resultant  inharmony  in 
the  relations  of  the  upper  and  lower  lips,  as  well  as  the  unpleasing 
angle  between  the  upj^er  lip  and  nose,  is  readily  seen.  It  can  l)e  imagined 
how  great  would  have  been  the  improvement  in  the  facial  lines  had 
that  tooth  developed  normally  and  the  u])per  arch  ))een  enlarged  to 
accommodate  it. 

Since  this  is  true,  what  must  we  think  of  the  fre(juently  advocated 
j)ractice  of  extracting  one  or  both  lateral  incisors  or  even  canines  in  the 
hope  of  improving  the  facial  lines? 


FACIAL  ART 


719 


The  j)rofile  on  thv  loft  of  Fi<;'.  741  shows  the  effect  on  the  facial  lines 
of  an  effort  to  prevent  nialocchision  by  the  extraction  of  the  perfectly 
sound  four  first  permanent  molars  at  the  age  of  nine  years,  which 
is  in  keeping  with  a  beUef  still  practised  by  many  of  the  old  school.  We 
need  possess  very  little  artistic  perception  to  readily  detect  the  great 
inharmony  of  the  mouth  with  the  other  features.  The  lack  of  balance 
is  so  pronounced  as  possibly  to  create  the  impression  that  all  the  teeth 
have  been  lost,  and  that  the  patient  is  wearing  badly  proportioned 
artificial  dentures. 


Fig.  740 


The  profile  on  the  right  of  Fig.  741  shows  the  facial  lines  restored 
to  normal  balance,  or  as  nearly  so  as  was  possible  at  that  age  of  the 
patient,  established  by  the  placing  of  the  teeth  that  remained  in  their 
normal  relations.  Fig.  899  shows  this,  and  the  case  ready  for  the  inser- 
tion of  artificial  substitutes  for  the  missing  molars. 

Fig.  742  shows  the  profile  of  a  face  where  extraction  of  both  upper 
first  premolars  was  resorted  to  by  the  writer  several  years  ago  in 
carrying  out  the  old  plan  of  treatment  for  the  reduction  of  "labial 
protrusion  of  the  upper  incisors,"  or  a  case  belonging  to  Division 
1  of  Class  II.  The  effect  of  this  treatment,  instead  of  improving  the 
facial  lines,  especially  the  angle  of  the  nose  with  the  upper  lip,  was  to 
cause  their  greater  inharmony  and  has  been  the  occasion  of  lasting 
regret. 

The  writer  wishes  to  indelibly  impress  on  the  mind  of  the  student 
that  since  normal  balance  of  the  lines  of  the  mouth  with  those  of  the 
other  features  is  dependent  on  the  normal  occlusion  of  the  teeth,  they  are 
necessarily  thrown  out  of  balance  and  out  of  harmony  just  in  proportion 


720 


ORTIWDUXTIA 


Fig.  741 


Fig.  742 


ETIOLOGY  OF  MALOCCLUtiWN  721 

as  the  teeth  are  out  of  normal  occlusion,  and  that  since  extraction  always 
produces  malocclusion  just  in  proportion  to  the  number  of  teeth  ex- 
tracted, where  malocclusion  did  not  previously  exist,  and  exaggerates 
and  complicates  it  where  already  existing,  its  effect  on  the  facial  lines 
is  inevitably  as  inharmonious,  not  to  say  deforming,  as  its  practice  is 
unpardonable. 

Extraction  is  further  discussed  in  the  section  on  Treatment. 


ETIOLOGY  OF  MALOCCLUSION 

As  we  have  already  noted,  malocclusion  is  the  result  of  failure  on 
the  part  of  nature  to  carry  to  completion  the  normal  plan  of  building 
the  human  denture — the  arrest  or  modification  of  the  forces  operative 
in  the  building.  As  these  forces  are  numerous  and  necessarily  compli- 
cated by  their  co-relations,  it  is  not  surprising  that  the  perfectly  normal 
human  denture  is  rarely  found.  Indeed,  the  perfectly  normal  in  dentures, 
as  in  human  beings,  or  in  the  lower  animals,  or  in  plants,  is  rare.  If  the 
conditions  for  growth  and  development  of  the  teeth  and  jaws,  bones  of 
the  face,  the  throat,  the  nose,  the  muscles,  etc.,  are  normal,  a  normal 
denture  w^ill  be  the  result;  but  a  long  time  is  necessary  for  the  building 
of  the  denture,  and  many  obstacles  may  intervene  to  prevent  its  normal 
unfoldings  in  growth.  Indeed,  any  pronounced  interference  with  the 
growth  of  any  of  the  different  factors  may,  and  usually  does,  result  in 
malocclusion  of  the  teeth.  As,  for  example,  any  pathological  condition 
of  the  nasal  passages,  resulting  in  the  necessity  for  mouth  breathing, 
will  not  only  prevent  the  normal  growth  of  the  nose,  but  will  modify 
the  vault  of  the  arch,  and  so  pervert  the  forces  of  the  lips  as  to  cause 
serious  disturbance  in  the  dental  arches  and  the  relations  of  the  teeth, 
as  is  shown  in  cases  belonging  to  Division  1,  Class  II.  And  not  only 
this,  but  serious  disturbances  in  the  growth,  health,  and  development  of 
the  child  also  often  result  from  mouth  breathing.  Again,  it  is  the 
writer's  belief  that  abnormal  enlargement  of  the  faucial  tonsils  is  the 
principal  cause  in  the  production  of  malocclusion  belonging  to  Class  III, 
at  least  in  the  primary  stages,  the  enlarged  tonsils  seeming  to  provoke 
a  desire  on  the  part  of  the  child  to  habitually  shove  the  lower  jaw  forward 
until  mal-locking  of  the  cusps  of  the  molars  results.  Thus,  perversion  of 
occlusal  and  muscular  forces  is  brought  about  and  the  most  progressive 
of  all  forms  of  malocclusion  established. 

Premature  Loss  of  Deciduous  Teeth. — The  deciduous  teeth  not  only 
perform  the  important  function  of  masticating  the  food  required  by  the 
child  up  to  the  period  of  their  normal  loss  and  their  replacement  by  the 
succeeding  permanent  teeth,  but  they  also  assist  in  a  mechanical  way  in 
the  development  of  the  alveolar  process,  and  probably  in  the  develop- 
ment of  the  jaws  as  well. 
46 


722  ORTHODONTIA 

The  permanent  teeth  heinfjj  hiro^er  and  more  numerous  than  the 
deciduous,  the  greater  space  recjuired  for  tliem  is  provided  principally  by 
the  lengthening  of  the  lateral  halves  of  the  dental  arches.  This  is  influ- 
enced largely  hy  the  development  and  eruption  of  the  ])ermanent  molars 
posterior  to  the  deciduous  molars.  If  the  mesio-distal  diameters  of  the 
deciduous  teeth  he  not  impaired  hy  caries  and  the  teeth  remain  the 
normal  period,  the  first  permanent  molar  in  taking  its  position  in 
the  arch  must  force  its  way  between  the  second  deciduous  molar  and 
the  ramus  of  the  jaw,  if  below,  or  the  maxillary  tuberosity  if  above. 

Coincident  with  the  growth  of  the  bones  of  the  head  and  face  the 
maxillary  bones  are  developed  downward  and  forward,  the  mandible 
lengthened  and  deepened,  and  the  deciduous  teeth  carried  forward. 
If,  however,  one  of  the  deciduous  teeth  be  prematurely  lost,  as,  for 
example,  the  upper  second  molar,  the  erupting  permanent  molar  will 
be  unable  to  exert  its  normal  force  in  crowding  the  deciduous  teeth 
forward,  l)ut  instead,  meeting  with  no  resistance,  it  will  move  forward 
prematurely  and  more  rapidly  than  normal,  into  the  space  of  the  missing 
tooth.  If,  meanwhile,  no  teeth  have  been  lost  in  the  same  side  of  the 
opposing  arch,  the  wedging  process  will  have  pushed  forward  the 
lower  deciduous  teeth  and  the  more  normal  development  in  the  lower 
arch  will  have  occurred.  There  will  thus  be  an  inequality  between  the 
jaws  on  the  affected  side  with  the  establishment  of  malocclusion.  And 
this  is  not  the  only  evil,  for  the  space  occupied  by  the  lost  tooth  having 
been  closed  or  greatly  diminished,  the  eruption  of  the  succeeding  per- 
manent tooth  (the  second  premolar)  will  be  prevented  entirely,  or  it 
will  be  forced  into  buccal,  or,  possibly,  lingual  occlusion,  as  in  Figs.  743 
and  744.  The  shortened  lateral  half  will  not  develop,  and  the  upper  arch 
will  consequently  be  smaller  than  normal,  which  must  result  in  mal- 
occlusion of  the  teeth. 

A  point  of  much  importance  in  connection  with  this  phase  of  the 
subject  which  may  as  well  be  discussed  here  is  that,  although  the 
first  permanent  molar  is  temporarily  displaced  by  its  moving  prema- 
turely forward,  the  writer  believes  it  is  always  found  in  its  normal 
mesio-distal  position,  even  in  these  cases,  ultimately,  or  at  the  time 
of  the  completion  of  the  denture.  Indeed,  even  in  two  cases  in  each 
of  which  three  upper  premolars  had  failed  to  develop,  the  first  perma- 
nent upper  molars  were  not  found  farther  mesially  than  normal  at  the 
maturity  of  the  patient.  And  the  reason  is  plain.  There  was  nothing 
to  force  them  forward  after  the  second  and  third  molars  had  taken 
their  places  in  the  arch  and  ceased  their  wedging  influence,  all  the 
lack  of  development  of  the  arch,  which  was  great,  being  in  its  anterior 
portion. 

This  premature  movement  of  the  molar  to  its  ultimately  normal 
position  is  easily  understood  by  a  study  of  Figs.  743  and  744,  which  show 
two  instances  in  which  premature  loss  of  deciduous  second  molars  resulted 


ETIOLOGY  OF  MALOCCLUSION 


723 


in   nuiloc'clusion,   one   shown   during   the  growth   of   the   denture   and 
the  other  at  maturity. 

Another  point  of  interest  in  connection  with  this  subject  is  that  this 
dispUicenient  mesially  may,  and  often  does,  result  in  the  mal-locking 
of  the  lower  first  molars  with  the  upper,  and  in  this  way  becomes  the 
prime  cause  of  the  establishment  of  the  subdivision,  or,  if  on  both  sides, 
the  full  second  division  of  Class  II. 


Fig.  743 


While  probably  the  greatest  harm  results  from  the  premature  loss 
of  the  second  deciduous  molar  or  canine  in  either  arch,  the  principle 
applies  to  the  loss  of  any  of  the  deciduous  teeth,  the  difference  being 
only  in  degree. 

Fig.  744 


The  mechanical  influence  of  the  deciduous  teeth  in  the  development 
of  the  dental  arches  is  so  important  that  they  should  not  only  by  all 
means  be  retained  their  full  normal  period,  but,  if  they  become  affected 
by  caries,  their  full  mesio-distal  diameters  should  be  restored  by  suitable 
fillings  after  sufficient  separation.     Likewise,  if  a  deciduous  tooth  be 


724  ORTHODONTIA 

lost  tliroui!;]!  the  premature  absorption  of  its  root,  the  full  S})ace  oeeu})ied 
by  it  should  be  maintained  by  some  suitable  retaining  device. 

Prolonged  Retention  of  Deciduous  Teeth. — One  or  more  of  the  deciduous 
teeth  are  occasionally  rt>tained  beyond  the  normal  period.  In  this 
event  the  succeeding  tooth  will  either  be  prevented  from  erupting  or 
will  be  deflected  to  a  malposition. 

Loss  of  Permanent  Teeth. — AMiat  has  already  been  stated  in  regard 
to  the  mechanical  influence  of  the  deciduous  teeth  in  assisting  the  nor- 
mal development  of  the  dental  arches  and  promotion  of  harmony  of  the 
facial  lines  is  e(|ually  applicable  to  the  permanent  teeth  up  to  the  period 
of  their  full  eruption,  or  until  the  last  of  the  molars  has  taken  its 
position.  This  is  a  point  of  such  importance  that  it  should  be  carefully 
considered  by  all  students  of  occlusion.  If  one  or  more  of  the  permanent 
teeth  anterior  to  erupting  molars  be  extracted,  the  wedging  process, 
so  necessary  in  developing  the  arch,  serves  only  to  close  the  space  thus 
made,  and  there  will  be  no  carrying  forward  of  the  teeth  and  process. 
The  evil  eft'ects  already  enumerated  as  arising  from  unequal  develop- 
ment of  the  two  arches  will  follows  It  should  also  be  borne  in  mind 
that  the  interdependence  of  the  teeth  is  so  great  at  all  times  that  the 
loss  of  one  or  more  at  any  period  in  their  history  must  have  a  marked 
influence  on  the  remaining  teeth.  Especially  is  this  true  of  the  loss  of 
the  lower  first  permanent  molars.     (See  page  830.) 

Tardy  Eruption  of  Permanent  Teeth. — It  occasionally  happens  that  a 
tooth,  with  or  without  apparent  cause,  fails  to  erupt,  and  remains 
embedded  in  the  alveolar  process  for  months,  or  even  years.  Usually 
the  space  is  partially  or  wholly  closed  by  the  adjoining  teeth.  The  im- 
paction of  the  canine  is  the  most  common  of  any  of  the  teeth,  owing  to 
the  fact  that  it  erupts  after  both  its  mesial  and  distal  associates,  and 
must  in  all  cases  meet  more  or  less  resistance  from  them.  If,  later, 
efforts  tow^ard  eruption  occur,  the  tooth  must  necessarily  be  deflected,  or 
force  other  teeth  into  malposition. 

Supernumerary  Teeth. — Supernumerary  teeth,  as  their  name  implies, 
are  anomalies,  or  extra  teeth  above  the  normal  number  of  thirty- two.  In 
outline  they  rarely  resemble  any  of  the  typical  tooth  forms,  being  most 
commonly  peg-shaped  or  conical.  Although  they  may  erupt  in  any 
part  of  the  dental  arches,  or  even  nearly  cover  the  entire  vault  of  the  upper 
arch,  as  shown  in  a  model  in  the  WTiter's  collection,  and  also  in  two  or 
three  other  well-known  cases,  their  favorite  location  is  between  the 
central  incisors,  in  the  region  of  the  laterals,  or  in  the  bucco-embrasial 
spaces  between  the  molars.  The  reason  for  their  appearance  is  not 
clearly  established. 

Habits. — The  habit  of  sucking  the  thumb,  lip,  or  tongue,  or  that 
modern  and  highly  pernicious  instrument  known  as  a  "pacifier,"  so 
frequently  formed  by  yoimg  children,  will  not  only  cause  malocclusion 
of  the  deciduous  teeth,  but  may  and  often  does  so  pervert  the  functions 


ETIOLOdY  OF  MALOCCLUSION  725 

of  the  lips  or  tongue  as  to  ultimately  lead  to  marked  malocclusion  of  the 
permanent  teeth. 

The  pernicious  habit  of  biting  the  lower  lip,  or  pressing  the  occlusal 
edges  of  the  upper  teeth  against  its  outer  surface,  has  a  tendency  to  move 
the  upper  centrals  forward,  thus  lessening  their  natural  resistance  to  the 
narrowing  of  the  lateral  halves  of  the  arch. 

This  habit  is  very  common,  is  often  extremely  difficult  to  overcome, 
and  probably  accounts  for  many  ultimate  failures  in  orthodontic  treat- 
ment. It  is  always  a  marked  accompaniment  of  cases  belonging  to 
Division  1  of  Class  II  and  its  subdivision,  and  unless  it  be  overcome 
and  the  normal  functions  of  the  lips  regained,  the  incisors  cannot  be 
kept  in  their  normal  positions. 

Another  habit,  although  more  rare,  that  of  resting  the  tongue  between 
the  upper  and  lower  incisors,  produces  the  effect  shown  in  Fig.  745. 

Fig.   745 


The  pressure  upon  the  incisal  edges  prevents  full  eruption  and  holds 
the  teeth  in  infra-occlusion,  while  the  molars,  being  held  apart  much 
of  the  time,  lengthen  into  positions  of  supra-occlusion  from  lack  of 
resistance. 

Disuse. — The  structure  and  history  of  the  jaws  and  teeth  show  that 
they  were  intended  for  much  use.  There  can  be  little  doubt  that  the 
modern  methods  of  food  preparation  tend  to  such  disuse  of  the  jaws 
and  teeth  as  to  have  a  marked  general  effect  in  causing  malocclusion. 

Abnormal  Frenum  Labiorum. — A  somewhat  common  form  of  malocclu- 
sion is  distinguished  by  a  space  between  the  upper  central  incisors,  and 
occasionally,  although  very  rarely,  between  the  lower  centrals.  This 
space  varies  in  width  from  one  to  four  and  even  five  millimeters,  always 


720  ORTHODONTIA 

presenting  an  unpleaslng  aj)pearance  and  interfering  witli  speeeli  in 
proportion  to  its  widtli.  Tiie  cause  of  the  deformity  is  abnormal  develop- 
ment and  attachment  of  the  fremim  lahiorum,  which,  instead  of  being 
normal  in  size  and  ending  in  its  attachment  to  the  gum  about  five  milli- 
meters above  the  gingiva,  not  only  reaches  the  gingiva,  but  passes 
directly  between  the  teeth  and  is  attached  to  the  likewise  overdevel- 
oped mesio-lingual  tuft.  This  strong  fil)rous  ligament  keeps  the  teeth 
separated  by  its  mechanical  action. 

There  are  other  causes  of  malocclusion,  many  of  which  are  not 
clearly  understood,  and  their  discussion  here  would  be  unfruitful.  One 
which  has  claimed  much  prominence  in  the  past  is  heredity.  It  is 
now,  however,  believed  that  heredity  plays  an  unimportant  part  in 
the  production  of  malocclusion,  and  that  most  of  the  causes  are 
mechanical  and  operative  subsequent  to  birth. 


ALVEOLAR  PROCESS  AND  PERIDENTAL  MEMBRANE 

The  importance  of  a  thorough  knowledge  of  the  alveolar  process 
and  peridental  membrane  is  perhaps  greater  in  orthodontia  than  in  any 
other  branch  of  dentistry,  for  to  the  orthodontist  these  tissues  are  second- 
ary only  in  importance  to  the  teeth  themselves;  and  it  is  largely  owing 
to  our  intelligent  comprehension  and  handling  of  these  tissues  that 
we  are  enabled  to  successfully  correct  malpositions  of  the  teeth.  It 
is  unnecessary  to  here  enter  into  an  extended  discussion  of  these  struc- 
tures. 

No  thoughtful  person  can  study  the  arrangement  of  the  fibers  of  the 
peridental  membrane  without  being  impressed  with  their  wonderful 
perfection  of  adaptation  for  resisting  the  various  tooth  movements 
incident  to  occlusion  and  mastication,  and  a  knowledge  of  this  arrange- 
ment is  of  peculiar  interest  to  the  orthodontist,  enabling  him  to  better 
comprehend  not  only  the  amount  of  force  required  and  difficulties  to  be 
overcome  in  moving  teeth,  but  the  necessary  anchorage  to  be  gained 
from  teeth  in  performing  the  operation,  as  well  as  a  far  better  insight 
into  problems  of  retention. 

Tissue  Changes  Incident  to  Tooth  Movement. — When  the  proper  amount 
of  force  is  exerted  upon  the  teeth  to  be  moved,  "the  bending  of  the  pro- 
cess, and  the  absorption  of  bone,  principally  of  the  cancellous  structure 
between  the  external  and  internal  plates, "i  occurs. 

In  youth,  or  before  the  bone  has  become  dense,  it  permits  of  much 
bending,  so  that  incisors  may  be  moved  out  of  inlock  in  a  few  hours, 
or  the  lateral  halves  of  the  arch  may  be  widened  in  a  very  few  days. 
This  is  easily  explained  when  we  remember  the  cancellous  structure  of 

1  Dr.  F.  B.  Noyes. 


ALVEOLAR  PROCESS  AND  PERIDENTAL  MEMBRANE       727 

the  bone,  the  inelasticity  of  the  fibers  of  the  peridental  membrane,  and 
their  very  strong  attachment  to  it. 

While  more  or  less  springing  of  the  bone  is  probably  always  an  accom- 
paniment of  tooth  movement,  yet  in  proportion  as  the  bone  becomes 
dense  with  age,  so  the  modification  of  the  process  attendant  upon 
tooth  movement  changes  from  springing  to  the  slower  action  of  absorp- 
tion and  the  still  more  slow  deposition  of  bone. 

Coincident  with  the  changes  in  the  bone  there  are  also  pronounced 
changes  taking  place  in  the  peridental  membrane.  As  force  is  exerted 
on  the  moving  tooth  the  membrane  is  compressed  in  front  of  it,  between 
it  and  the  wall  of  the  socket,  while  a  greater  tension  of  the  fibers  of 
the  membrane  takes  place  on  the  opposite  side.  As  a  result  of  this 
tension  and  compression  the  nerves  of  the  membrane  are  impinged 
upon,  causing  a  greater  or  less  sense  of  pain,  which,  as  a  result  of  the 
slight  movement  of  the  tooth  and  temporary  paralysis  of  the  nerves 
from  pressure,  subsides  more  or  less  quickly  according  to  the  amount 
of  inflammation  present. 

As  a  result  of  this  pressure  the  absorbent  cells,  or  osteoclasts,  are 
stimulated  to  increase  in  number  and  activity.  They  immediately 
engage  in  the  absorption  of  the  portion  of  bone  most  involved  in  the 
movement,  as  well  as  of  the  bone  attachments  of  the  fibers  on  greatest 
tension. 

While  these  changes  are  taking  place  the  osteoblasts  have  become 
active,  and  have  begun  filling  up  the  depression  and  reattaching  the 
fibers  by  the  redeposition  of  bone.  But  as  this  is  a  much  slower  process 
than  that  of  absorption,  the  tooth  is  found  to  be  more  or  less  loose  in 
its  socket  at  the  completion  of  its  movement,  as  well  as  long  after, 
necessitating  its  being  supported  by  means  of  the  retaining  devices 
until  the  deposition  of  bone  shall  be  complete  and  the  socket  modified 
for  its  support  in  its  new  position. 

If  a  tooth  be  elevated  in  its  socket,  the  principal  change  involves 
the  peridental  membrane.  The  fibers  at  the  end  directly  resisting  this 
movement  are  severed,  and  the  oblique  or  suspensory  fibers  are  stretched 
and  recurved  upon  themselves.  The  result  of  the  partial  withdrawal  of 
the  conical  root  is  increased  space,  not  only  at  the  end,  but  also  on  the 
sides  of  the  root,  so  that  there  is  considerable  freedom  of  movement  of 
the  tooth,  necessitating  the  deposition  of  bone  over  the  entire  surface 
of  its  socket,  as  well  as  increase  of  height  of  margin  and  a  reorganiza- 
tion of  the  entire  system  of  fibers.  This  explains  the  necessity  for 
such  protracted  suspensory  retention,  and  the  comparative  ease  with 
which  the  movement  of  elevation  may  be  performed. 

In  the  movement  of  depression — the  most  difficult  tooth  movement 
— the  bone  must  be  absorbed  by  the  osteoclasts  over  the  entire  surface 
of  the  alveolus  to  allow  for  the  advance  of  the  root  of  conical  form. 
The  fibers  of  lateral  support  are  stretched,  while  the  suspensory  fibers 


728  ORTHODONTIA 

are  also  stretched,  and  severed  at  their  points  of  attachment  to  the  hone, 
therehv  necessitating  more  disturhance  of  tissues  and  retjuiring  more 
force  and  time  than  any  other  of  the  seven  movements. 

In  the  rotation  of  a  tooth,  as  probably  most  of  the  fibers  indirectly 
tend  to  prevent  the  tooth  from  turning  in  its  socket,  and,  in  addition, 
there  are  an  unusual  number  at  the  four  angles  so  arranged  as  to  directly 
resist  such  action,  much  absorption  of  the  fibers,  as  well  as  nuich  absorp- 
tion and  bending  of  the  bone  are  necessary,  which  easily  accounts  for 
the  greater  amount  of  time  and  force  required  to  perform  this  movement. 

In  all  cases  of  tooth  movement  a  large  number  of  the  fibers  of  the 
membrane,  as  well  as  the  bone,  remain  on  tension  long  after  the  move- 
ment is  complete,  the  force  they  exert  tending  to  draw  the  tooth  back 
to  its  original  position,  thus  necessitating  considerable  support  from  the 
retaining  devices  until  these  tissues,  as  well  as  the  muscles,  have  become 
thoroughly  reestablished  in  harmony  with  the  tooth  in  its  new  position. 

In  accomplishing  the  movement  of  teeth  lingually,  labially  (or  bue- 
cally),  mesially  or  distally,  the  principal  change  is  in  the  position  of  the 
crow^n  of  the  tooth,  it  being  tipped  into  its  correct  position.  The  usual 
supposition  is  that  the  tooth  in  the  alveolar  process  acts  as  a  lever, 
the  crown,  or  long  end  of  the  lever,  moving  in  one  direction,  and  the 
apex  of  the  root  in  the  opposite  direction.  To  make  clear  these  sup- 
posed changes,  and  especially  the  extent  of  the  movement  of  the  apex, 
writers  have  frequendy  used  the  illustration  of  a  post  driven  about  two- 
thirds  its  length  into  the  earth.  If  force  be  exerted  at  right  angles  to 
a  side  of  the  post  near  its  top,  the  post  will  act  as  a  lever  in  the  dis- 
placement of  the  soil,  the  two  ends  of  the  lever  moving  in  opposite 
directions,  and  the  pivotal  point  being  somewhere  near  the  beginning 
of  the  last  third  of  the  embedded  portion. 

The  illustration  is  a  poor  one  and  very  misleading,  as  the  mechanical 
conditions  are  very  different.  Doubtless  this  would  be  the  result  if 
the  tooth,  like  the  post,  had  but  one  resistant  substance  and  that  equally 
distributed  in  all  directions  about  its  root;  but,  as  is  shown  by  a  study 
of  the  alveolar  process,  the  bone  varies  greatly  in  thickness  over  dif- 
ferent portions  of  the  root  and  in  different  teeth,  so  the  amount  of 
displacement  of  the  apex  of  the  root  of  a  tooth  depends,  frequently,  upon 
the  location  and  the  movement  of  the  tooth,  and  whether  one  tooth  or 
a  number  in  the  same  region  are  being  moved  in  the  same  direction. 
In  reality  there  may  be  little  or  no  displacement  of  the  apex,  or  there 
may  be  considerable. 

In  the  first  place,  the  alveolar  process  is  not  a  level  plane,  like  that 
in  which  the  post  is  implanted,  but  a  projection  or  high  ridge,  of  elastic 
Structure,  and  admits  of  some  bending  laterally,  its  susceptibility  to 
this  action  increasing  proportionately  as  we  approach  the  top.  The 
pronounced  bending  of  the  process  is  a  matter  of  common  observation 
in  efforts  at  extraction. 


ALVEOLAR  PliOCESS  AND  PERIDENTAL   MEMBRANE       729 

Again,  tlie  mechanical  ditt'erence  in  the  attachment  of  the  post  to 
the  soil  and  the  tooth  to  the  alveolar  process  is  such  as  to  still  further 
add  greatly  to  the  difference  in  the  results  of  their  respective  movements. 
As  the  apex  of  the  root  is  implanted  deeply  in  the  bone,  which  is  greatly 
thickened  in  its  lingual  direction  and  reinforced  by  the  strong  cortical 
layer  of  the  alveolar  process,  its  movement  lingually  could  not  well 
take  place  as  a  result  of  springing.  This  movement  is  further  strongly 
resisted  by  the  innumerable  inelastic  fibers  that  encapsule  the  apex, 
radiating  in  all  directions  for  its  firmest  possible  attachment  to  the  bone, 
their  ends  being  enclosed  in  its  structure. 

So  in  the  labial  movement  of  the  crown,  the  lingual  movement  of 
the  apex  of  the  root  is  not  only  resisted  by  the  bone  in  front,  but  also 
behind  and  on  each  side,  by  reason  of  its  attachment,  while  with  the  end 
of  the  post  little,  if  any,  resistance  is  offered  by  the  soil  behind  or  on 
either  side,  but  only  by  that  in  front. 

Another  difference.  ,  The  force  for  the  movement  of  the  post  is 
applied  remote  from  the  fulcrum,  while  the  force  exerted  on  the  tooth 
by  the  ligature  is  applied  close  to  the  fulcrum,  or  at  a  point  best  calcu- 
lated to  facilitate  the  bending  of  the  alveolar  process  in  the  labial 
direction. 

Again,  unlike  the  post,  several  teeth  may  be  associated  in  the  move- 
ment, which  adds  still  further  to  the  probabilities  of  the  labial,  as  well 
as  adding  correspondingly  to  the  improbabilities  of  the  lingual  move- 
ment of  their  apices. 

In  the  movement  buccally  of  the  upper  molars  there  is  bending  or 
absorption  of  the  outer  plate,  the  palatal  roots  are  elevated  in  their 
sockets  to  make  easier  the  tipping  of  the  crown,  with  probably  no  move- 
ment at  the  apices  of  the  buccal  roots,  unless  it  be  that  they  are  forced 
deeper  into  their  sockets.  In  the  lingual  movement  of  the  same  teeth 
there  is  more  or  less  bending  of  the  process,  the  forcing  deeper  into  its 
socket  of  the  palatal  root,  with  perhaps  some  elevation  in  their  sockets 
of  the  buccal  roots. 

In  the  same  movements  of  the  lower  molars  there  is  greater  displace- 
ment of  the  apices  of  the  roots  in  the  opposite  direction  from  which  the 
crowns  are  moved,  owing  to  the  great  thickness  of  the  buccal  plate  of  the 
alveolar  process. 

In  the  movement  of  teeth  mesially  or  distally  the  bending  of  the  bone 
must  be  less,  the  movement  of  the  teeth  more  nearly  resembling  the 
movement  of  the  post,  the  apex  moving  slightly  in  the  opposite  direction 
from  the  crown,  as  in  Fig.  801. 

The  Pulp. — While  the  pulp  of  the  tooth  is  a  tissue  more  or  less  involved 
in  tooth  movement,  when  the  operation  is  properly  performed  this 
tissue  is  practically  undisturbed  and  should  suffer  no  real  injury.  On 
the  other  hand,  its  normal  function  may  be  so  interfered  with  as  to 
cause  it  to  suffer  marked  disturbance  and  even  complete  devitalization, 


7:U)  ORTHODONTIA 

especially  if  the  movement  he  conducted  too  rapidly,  or  the  force  be  too 
abruptly  applied.  With  modern  regulating  appliances,  however,  the 
most  perfect  control  of  the  force  for  the  movement  of  teeth  is  now  easily 
possible,  so  that  other  than  very  slight  inflammation  is  inexcusable. 

It  is  often  desirable  to  perform  tooth  movement  soon  after  the 
eruption  of  the  teeth,  or  before  the  root  is  fully  formed,  the  end  of 
the  root  then  having  a  broad,  funnel-shaped  opening.  If  the  movement 
be  intelligently  performed,  the  pulp  at  this  age  should  suffer  no  greater 
disturbance  than  when  the  root  is  fully  calcified. 

Physiological  Changes  Subsequent  to  Tooth  Movement. — Important 
physiological  changes  in  the  tissues  involved  also  occur  subsequent 
to  tooth  movement.  To  better  understand  these  changes  we  must 
keep  in  mind  the  conditions  previously  existing.  The  development  of 
malocclusion  is  gradual,  and,  in  proportion  as  the  positions  of  the  teeth 
deviate  from  the  normal,  a  corresponding  deviation  is  necessitated 
in  the  development  of  the  alveolar  process,  and,  to  a  greater  or  less 
degree,  in  the  bones  of  the  jaws,  vault  of  the  arch,  the  nasal  tract,  and 
the  muscles  of  the  face.  All  being  out  of  harmony,  the  tendency  is  usually 
to  favor  still  greater  inharmony,  or  departure  from  the  normal,  as  growth 
and  development  progress. 

After  the  crowns  of  the  teeth  have  been  moved  into  correct  positions 
in  the  line  of  occlusion  and  harmony  of  the  occlusal  planes  has  been 
established,  the  positions  of  the  teeth  and  function  of  the  occlusal  planes 
have  been  so  changed  as  to  exert  a  different  influence  upon  the  bones 
and  muscles.  The  tendency  of  the  forces  now  is  to  stimulate  nature 
to  efforts  toward  the  rearrangement  of  these  tissues  and  their  normal 
growth  and  development,  in  accordance  with  the  demands  of  the  teeth 
in  their  new  positions  and  with  her  original  design.  Evidences  are 
common  throughout  surgery  of  nature's  wonderful  inherent  power  to 
remedy  her  defects,  and  of  her  prompt  response  as  soon  as  favorable 
conditions  for  self-assertion  have  been  established.  The  natural  changes 
following  the  correction  of  malocclusion  are  often  pronounced  and 
gratifying. 

The  cognizance  of  the  possibilities  of  these  changes  should  in  many 
instances  modify  our  plan  of  treatment  from  what  it  would  be  were 
we  ignorant  of  them.  Very  frequently  where  there  has  been  change 
of  position  of  a  number  of  teeth,  especially  in  both  arches,  some  may 
occupy  planes  of  greater  elevation  than  others,  or  the  cusps  of  some 
may  not  occupy  exactly  normal  mesio-distal  relations;  but  if  we  have 
succeeded  in  placing  the  teeth  so  that  the  inclined  planes  of  their  occlusal 
surfaces  favor  their  normal  positions,  their  proper  heights  and  relations 
will  gradually  become  established  as  a  result  of  occlusion.  In  some 
cases  the  incisors  may  apparendy  be  much  too  short,  but  after  a  few 
weeks  or  months,  when  the  posterior  teeth  shall  have  become  settled  in 
their  new  positions,  the  length  of  overbite  of  incisors  will  be  normal. 


ALVEOLAR  PROCESS  AND  PERIDENTAL  MEMBRANE       731 

Another  noticeiil)le  aiul  most  important  change  following  tooth  move- 
ment is  the  growth  of  the  alveoUir  process,  as  well  as  that  of  the  co- 
related  bones,  muscles,  and  tissues  which  have  been  arrested  in  their 
growth  as  a  result  of  malocclusion  and  the  perversion  of  the  function 
of  the  teeth.    This  is  illustrated  in  the  following  case  of  historical  interest, 

Fig.  746 


Figs.  7-i6  and  747,  where  the  pronounced  arrest  of  these  tissues  is  noted, 
especially  that  of  the  alveolar  process  in  the  region  of  the  roots  of  the 
upper  incisors  and  vault  of  the  arch. 

After  the  arch  had  been  enlarged  and  the  crowns  of  the  incisors 
carried  forward,  the  positions  of  the  teeth  are  shown  in  Fig,  748,  which 


Fig.  747 


marks  the  beginning  of  the  period  of  retention.  But  it  will  be  noted 
that  the  incisors  stand  at  a  very  pronounced  angle  of  inclination,  with 
the  deep  depression  over  the  apices  of  the  roots  of  the  incisors  more 
pronounced. 


732  ORTHODONTIA 

After  faitliful  mechanical  retention  for  nearly  three  years,  a  fjratifying 
discovery  was  made,  which  is  noted  in  Figs.  749  and  750,  namely,  the 
complete  normal  development  of  the  alveolar  process  and  the  shifting 
forward  of  the  apices  of  the  roots  of  the  incisors  until  these  teeth  stood 

Fig.  748  Fig.  749 


in  their  normal  upright  positions.  The  vault  of  the  arch  has  been 
remodelled,  the  floor  of  the  nose  widened,  and  probably  the  maxillary 
and  co-related  bones  and  tissues  have  been  greatly  modified  toward  the 
normal  in  development. 

This  was,  indeed,  a  gratifying  discovery  to  the  writer/  for  he  realized 
that  it  was  the  fulfilment  of  a  physiological  law  of  growth  following  the 


Fig.  7.50 


establishment  of  normal  occlusion  and  normal  function  of  the  teeth. 
He  has  since  verified  this  in  a  large  number  of  other  cases,  many  of  which 
were  much  more  pronounced  in  the  arrest  in  their  development  than 

'  Angle,  Malocelusinn  of  the  Teeth,  7th  edition. 


MODELS  733 

this  case.  It  is  now  standard  practice  and  there  can  no  longer  he  any 
excuse  for  the  extraction  of  teeth  in  these  cases,  founded  on  the  time- 
honored  su])position  of  the  old-school  practitioners  that  the  jaws  are  too 
small  for  the  teeth. 

Other  cases  verifying  this  law  will  be  shown  in  the  section  on 
Treatment. 

It  is  well  to  remember  that  this  sul^sequent  development  is  very  active 
and  (juick  to  respond  in  youth,  or  during  the  period  of  eruption  of  the 
incisors  and  for  some  years  later,  but  that  it  diminishes  in  activity  in 
proportion  to  the  age  of  the  patient — another  strong  evidence  of  the 
importance  of  early  treatment  of  malocclusion. 

That  the  bone  cells  may  be  stimulated  and  more  rapid  and  com- 
plete development  effected  in  these  cases  by  mechanical  means  is  now 
proved. 

That  the  most  favorable  tissue  changes  possible  may  follow  tooth 
movement  it  is,  of  course,  of  the  utmost  importance  in  all  cases  that  all 
pathological  conditions  of  the  throat  and  nose  receive  the  most  careful 
attention  from  the  skilful  rhinologist. 


MODELS 

The  first  step  in  the  study  of  all  cases  preparatory  to  treatment  is 
the  taking  of  accurate  impressions  of  the  teeth,  from  which  accurate, 
articulating  models  of  both  arches  are  made.  Such  models  not  only 
assist  in  the  classification  and  diagnosis  of  cases,  but  also  aid  in  deter- 
mining the  proper  plan  of  treatment,  and  are  also  exceedingly  valuable 
for  reference  during  its  continuation,  for  by  comparing  the  models  with 
the  natiu'al  teeth  at  each  visit  of  the  patient  we  may  not  only  keep 
positively  informed  as  to  the  exact  movements  of  the  malposed  teeth, 
but  any  unfavorable  movement  of  the  anchor  teeth  may  also  be  imme- 
diately detected. 

Material  for  Impressions. — IModels  are  only  valuable  in  proportion 
as  they  are  accurate,  and  the  only  models  approximating  accuracy  are 
those  made  from  plaster  impressions.  These  models  must  show  not 
only  both  arches  and  the  relative  positions  of  the  teeth  and  cusps,  as 
well  as  the  vault  of  the  arch,  rugse,  and  gums,  but  must  also  correctly 
show  as  much  of  the  roots  and  their  positions  as  are  indicated  by  the 
gums  and  alveolar  process  up  to  the  point  where  the  attachment  of  the 
muscles  renders  obscure  the  further  shape  of  the  jaw. 

Models  sufficiently  perfect  cannot  be  made  from  impressions  taken 
in  modelling  compound  or  other  of  the  plastics. 

The  shape  of  the  jaw,  together  with  the  shapes  and  inclinations  of 
the  teeth,  make  the  removal  of  a  plastic  impression,  without  change  of 
form,  impossible.     The  degree  to  which  arrest  of  development  of  the 


734 


ORTHODONTIA 


alveolar  process  has  taken  place,  esjK'cially  in  the  region  of  the  roots 
of  the  incisors,  so  im})ortant  to  accurately  record  in  the  model,  can  only 
be  the  merest  supposition  in  a  model  made  from  a  plastic  impression. 


Fig.  751 


AYhen  the  correct  method  of  takino;  plaster  impressions  has  been 
learned  the  operation  occasions  but  little,  if  any,  more  trouble  to  the 
operator,  or  objection  from  patients,  than  if  one  of  the  plastics  were 
used. 

Fig.  752 


The  Trays. — The  writer's  trays,  shown  in  Figs.  751  and  752,  are 
best  suited,  being  much  higher  than  the  ordinary  trays.  In  taking  an 
impression  a  sufficiently  large  tray  should  be  selected,  which  should, 
if  necessary,  be  bent  to  conform  more  nearly  to  any  peculiarity  in  the 
shape  of  the  jaw;  this  will  not  injure  the  tray. 

Taking  the  Impressions. — Good  impression  plaster  is  mixed  in  the 
usual  way  and  carefully  distributed,  as  shown  in  Fig.  753,  the  shape 


MODELS 


735 


and  height  of  the  trays  making  hut  httle  impression  material  necessary. 
It  will  be  observed  that  the  greater  amount  is  placed  in  the  anterior 
part  of  the  tray  and  made  to  extend  over  the  outer  edge  of  the  rim, 
none  being  allowed  in  the  vault  of  the  tray. 

It  is  now  placed  squarely  in  position  and  the  plaster  allowed  to  rest 
evenly  in  contact  with  the  occlusal  edges  of  all  the  teeth,  but  not  forced 
up  into  position.  The  lip  is  then  raised,  and  the  plaster  extending  outside 
of  the  rim  of  the  tray  is  carried  high  up  underneath  it  with  the  finger. 
This  is  to  insure  the  expulsion  of  air,  as  well  as  a  high  impression. 
The  tray  is  then  forced  up  evenly  until  the  points  of  the  teeth  touch 
the  bottom  of  the  tray,  and  steadily  supported  upon  the  end  of  the 
index  finger  only.  To  expel  the  air  from  the  cheeks  they  are  now  gently 
manipulated,  but  not  drawn  down,  as  to  do  this  would  force  down 
a  portion  of  the  plaster  and  prevent  one  of  the  important  objects — 
viz.,  a  very  high  impression. 

Fig.  753 


It  should  be  allowed  to  remain  in  position  until  the  plaster  has  become 
thoroughly  set,  which  is  very  important,  as  the  harder  the  plaster  is 
allowed  to  become,  the  sharper  will  be  the  impression. 

The  tray  is  now  loosened  and  taken  away,  leaving  the  impression  in 
the  mouth.  It  is  essential  that  the  tray  should  loosen  easily  from  the 
impression;  hence  the  importance  of  its  being  kept  clean,  bright,  and 
smooth. 

Two  grooves  are  then  scraped  or  cut  in  the  hardened  plaster  on  a 
line  parallel  with  the  canine  teeth,  but  not  cut  quite  through.  Then 
with  a  quick  pry  with  the  point  of  a  knife  the  anterior  plate  is  loosened. 
The  lateral  pieces  are  then  broken  off  with  the  thumb  and  finger,  when 
the  large  piece  covering  the  roof  of  the  mouth  alone  will  remain.  This 
may  be  readily  worked  loose,  and  if  the  operation  has  been  carefully 
performed  the  impression  will  consist  of  four  pieces,  although  to  have  a 
much  greater  number  would  in  no  way  injure  it. 


730 


ORTHODONTIA 


After  the  pieces  of  the  impression  are  dry  tluT  are  united  by  means 
of  wax,  aiul  should  present  the  ap])earance  ilkistrated  in  Fig.  754. 

This  nietiiod  of  taking  impressions  preserves  the  fine  points  of  the 
interdental  sj)aces.  We  believe  it  to  l)e  the  only  practicable  way  of  taking 
an  accurate  impression. 

In  like  manner  the  impression  of  the  lower  arch  is  taken,  removed, 
and  united,  being  careful  to  observe  the  essential  points,  namely,  carry- 
ing the  impression  material,  which  has  been  built  uj)  and  outside  of  the 
anterior  part  of  the  rim  of  the  tray,  well  down  beneath  the  lip  with  the 


Fir,.   754 


finger,  and  after  forcing  the  tray  home  the  excess  plaster  on  the  sides  is 
carried  back  and  down  to  avoid  folds  in  the  cheek,  while  the  tray  is 
steadily  held  by  the  ends  of  two  fingers  of  the  left  hand,  one  to  rest  on 
the  top  of  each  lateral  half. 

Vamisliing  the  Impression.— The  impressions  being  united,  they 
should  be  coated  very  evenly  with  shellac  varnish.  At  the  expiration 
of  half  an  hour,  or  when  the  varriish  has  become  hard,  a  second  coat 
should  be  applied  over  the  occlusal  surfaces  of  the  teeth  and  rough 
points  only,  not  over  the  smooth  surfaces,  especially  the  labial  gum 
surfaces.  Dry  again,  and  then  apply  over  the  entire  impression  a  very 
thin,  even  coat  of  sandarac  varnish.^ 


'  It  is  important  that  both  of  these  varnishes  shall  be  of  the  proper  consistence, 
which  is  difficult  to  describe.  If  too  thin,  the  hard,  glossy  surface  will  be  wanting, 
and  it  will  be  difficult  to  separate  the  impression  without  injury  to  the  model.  If 
too  thick,  all  fine  tracings  of  the  impression  will  be  obliterated. 


MODELS 


T61 


The  Models.— After  drying  for  half  an  hour  the  impression  will  i)e 
ready  for  filling,  which  may  be  best  accomplished,  in  order  to  insure 
expulsion  of  air  bubbles,  by  quickly  and  carefully  painting  the  plaster 
into  the  tooth  cavities  with  a  small  camel's-hair  brush,  then  rapidly 
filling  with  a  spatula,  gently  shaking  for  a  while  (never  jarring),  after 
which  it  should  be  turned  bottom  upward  on  a  glass  slab  and  allowed 
to  thoroughly  set. 

Numerous  horizontal  and  vertical  grooves  are  then  made  in  the 
impression  (Fig.  755)  and  it  is  also  shaved  thin  over  the  occlusal  sur- 
faces of  the  teeth,  to  expedite  the  separation  of  impression  and  model. 
Should  any  air  cavities  be  found  in  the  model,  they  may  be  remedied 
by  the  use  of  a  delicate  brush  in  the  artistic  application  of  plaster  of  a 
creamy  consistence.  A  cusp  or  broken  tooth  may  in  like  manner  be 
repaired. 

Fig.  755 


The  models  may  now  be  trimmed,  and  not  only  will  there  be  a  surface 
as  smooth  as  polished  marble,  but  each  cusp,  all  the  interdental  spaces, 
and  the  rugse,  as  well  as  the  inclinations  of  the  roots,  and  even  the 
minute  "  stipples"  of  the  gum,  and  the  developmental  lines  of  the  enamel, 
will  be  accurately  and  beautifully  shown.  Any  coating  of  paint  or 
varnish  only  detracts  from  the  beauty  of  such  models. 

The  models  should  be  trimmed  according  to  lines  'of  graceful  propor- 
tions and  artistic  balance,  which  is  made  much  easier  by  the  use  of  the 
model  plane  and  combination  square,  shown  in  Fig.  756. 

After  they  are  trimmed,  the  models  should  be  carefully  compared 
with  the  natural  teeth,  and  the  occlusal  relations  indicated  by  two  or 
more  pencil  markings,  so  that  the  proper  points  of  contact  may  after- 
ward be  readily  found.  These  serve  the  purpose  much  better  than  any 
form  of  an  articulator. 
47 


738 


ORTHODONTIA 


As  soon  as  the  teetli  have  been  completely  moved,  another  imj^ression 
should  he  taken  and  models  made.  This  is  done  after  all  aj)j)liances 
have  been  removed  and  the  teeth  thorou^dily  cleansed,  and  immediately 
previous  to  adjusting  the  retaining  devices.  These  models  are  invaluable 
for  comparison  with  the  natural  teeth  during  the  period  of  retention,  as 
well  as  for  future  reference.' 

A  collection  of  fine,  accurate  models  is  not  only  an  incentive  to  keener 
interest  and  better  work,  but  is  a  most  valuable  form  of  "library"  in 
itself,  in  which  much  that  is  instructive  and  interesting  is  recorded 
that  can  never  be  reduced  to  writing. 

Models  should  never  be  mutilated  by  the  fitting  of  bands  and  appli- 
ances. While  they  may  serve  as  a  basis  for  general  measurements  for 
the  appliances,  the  fitting  can  only  be  properly  done  on  the  natural 
teeth. 


Fig.  756 


ilili!il'i'''Mlililihhl;liliMilililililililililiLlililili!ililililiiilili 
Model  plane. 


Photographs. — Quite  as  important  as  models  are  good  photographs 
of  the  patients'  faces,  in  which  are  represented  full  profile  and  front 
views  in  a  simple,  natural  pose.  These  are  far  preferable  and  more 
reliable  in  judging  the  harmony  and  inharmony  of  the  patient's  face  than 
is  a  plaster  cast  of  the  face, 

Rontgenographs. — Rontgenographs,  now  so  easily  and  quickly  made, 
are  often  of  great  value  in  settling  all  doubts  as  to  whether  teeth  be  missing 
or  their  exact  locations  and  forms  if  merely  embedded.  While  these 
points  may  be  determined  in  the  majority  of  cases  by  careful  inspection 
of  the  contour  of  the  alveolar  process,  and  digital  pressure,  together 
with  the  use  of  the  exploring  needle,  yet  when  any  doubt  exists  the 
rontgenograph  should  be  resorted  to.  Fig.  757  illustrates  a  case  as 
revealed  by  the  rontgenograph,  where  the  canine  is  so  deeply  embedded 
in  the  alveolar  process  as  to  baffle  the  ordinary  methods  of  diagnosis. 


'  For  a  more  complete  study  of  the  writer's  method  of  impression  taking;  and 
model  making  the  reader  is  strongly  recommended  to  a  most  thorough  treatise  in 
booklet  form  on  this  subject,  by  Dr.  Jos.  Griinberg,  of  Berlin,  for  sale  by  the  S.  S, 
White  Dental  Mfg.  Co. 


REGULA  TING  A I'PLIA NCES 


739 


Fig.  758  sliows  the  raro  case  of  a  missing  permanent  canine,  and 
the  absorption  of  the  root  of  the  deciduous  canine.  The  first  premolar 
is  about  to  erupt. 


Fig.  757 


Fig.  758 


REGULATING  APPLIANCES 


Two  plans  are  now  followed  in  the  designing  and  constructing  of 
regulating  appliances,  the  first  based  upon  the  belief  that  each  case  so 
radically  differs  from  all  other  cases  that  an  appliance  must  be  invented 
and  constructed  from  raw  material  to  meet  its  special  requirements. 
The  second  plan  recognizes  the  division  of  malocclusion  into  a  few 
clearly  defined  classes,  having  requirements  of  treatment  clearly  indi- 
cated, with  fixed,  standard  forms  of  ready-made  regulating  appliances 
acting  upon  definite  principles,  which  amply  provide  for  the  require- 
ments of  all  cases  belonging  to  each  class. 

The  first,  until  the  introduction  of  the  writer's  appliances,  was  the 
universal  plan,  having  come  down  to  us  from  the  earliest  history  of 
orthodontia;  indeed,  much  of  the  literature  of  the  science  consists  of 
descriptions  of  appliances  which  have  been  invented  to  accomplish 
tooth  movements  in  special  cases,  until  some  thousands  are  recorded, 
one  author  alone  boasting  of  many  hundreds,  ^^^len  something  may 
be  accomplished  in  the  following  of  this  plan,  it  should  require  no 
argument  to  prove  that  there  are  many  reasons  why  it  is  most  defective 
and  unscientific. 

First,  it  necessitates  that  each  dentist  shall  be  an  inventor,  and  it  is 
well  known  that  the  inventive  faculty  is  rather  a  natural  gift  than  an 
acquirement,  and  that  it  can  be  exercised  successfully  only  by  a  very 
few.  Then,  as  all  inventions  if  perfected  must  be  experimented  with, 
it  must  follow  that  each  case  so  treated  must  be  largely  in  the  nature 
of  an  experiment,  often  necessitating  many  changes  in  the  plan  and 


740  ORTHODONTIA 

construction  of  a])})liances.  Iloncc  all  treatment  upon  ,su''h  theory  must 
be,  and,  in  fact,  has  ever  been,  tedious  and  costly,  with  a  large  j>ercentage 
of  failures. 

Secondly,  another  o])jection  in  following  this  plan  is  that  the  construc- 
tion of  appliances  must  necessarily  l)e  more  or  less  crude  and  lacking 
in  requisite  proportions,  for  any  instrument  only  reaches  perfection  as  to 
size,  proportion,  temper,  strength,  and  finish  after  much  experimenting 
and  repeated  efforts  toward  perfection  in  manufacture. 

Finally,  another  objection  more  serious  than  all  is  that  as  the  plan 
is  empirical,  with  only  a  vague  and  indefinite  basis  from  which  to  reason, 
the  difficulties  in  teaching  and  practice  become  very  great  and  the 
results  greatly  limited.  After  a  life  of  practice  the  dentist  following 
this  plan  must  still  be  in  a  maze  of  experiments,  and  unable  to  impart 
much  information  that  could  be  of  assistance  to  those  who  may  begin 
practice  after  him. 

The  second  plan,  as  we  have  already  stated,  recognizes  the  practi- 
cability of  fixed,  standard  forms  of  devices  for  the  recjuirements  of 
tooth  movement  necessary  in  all  the  various  classes  of  malocclusion, 
the  proper  forms  having  been  arrived  at  as  a  result  of  careful  experi- 
mentation and  close  observation  in  a  very  large  number  of  cases  em- 
bracing the  greatest  variety  of  malocclusion.  Instead  of  hand-made 
productions  by  the  dentist,  which,  with  his  limited  experience  and  meager 
facilities,  mustahvays  fall  far  short  of  the  ideal,  they  are,  like  fine  watches, 
made  upon  elaborate  machinery  by  the  most  skilful  workmen. 

If  such  appliances  are  practicable,  it  must  at  once  l)econie  apparent 
that  the  advantages  from  their  use  must  be  very  great,  for,  instead 
of  being  confronted  with  a  confusing  and  almost  limitless  number  of 
devices,  which  can  at  best  only  serve  as  general,  vague,  and  often  delusive 
patterns  to  him,  the  student  has  but  to  thoroughly  familiarize  himself 
with  a  few  standard  devices  which  he  may  quickly  and  easily  apply. 

Again,  familiarity  with  and  repeated  use  of  standard  appliances  add 
greatly  to  the  possibilities  of  development  of  skill  and  judgment  in  their 
use,  as  in  the  case  of  the  frec|uent  use  of  favorite  patterns  of  pluggers 
or  excavators  which  have  also  been  made  by  skilled  experts.  And 
whether  or  not  ideal  standard  regulating  ajipliances  have  yet  l)een  reached, 
the  possibilities  and  positive  advantages  of  the  principle  over  that  of 
the  first  plan  are  so  marked  that  we  think  all  teachers  who  are  inter- 
ested in  this  branch  should  make  effort  toward  that  direction,  rather 
than  to  assist  in  perpetuating  a  principle  so  obviously  defective  that  it 
must  be  apparent  to  all  that  it  is  a  positive  hindrance  to  the  real  progress 
of  orthodontia. 

It  is  now  well  known  that  most  of  the  real  progress  in  dentistry  and 
surgery,  and,  we  may  add,  in  orthodontia,  has  been  made  since  the 
dentist,  surgeon,  and  orthodontist  were  relieved  of  this  impractical 
task  by  experts  who  have  produced  instruments  so  perfect  in  design. 


REGULATING  APPLIANCES  741 

construction,  and  linisli  us  to  be  often  in  advance  of  the  comprehension 
and  skill  of  those  who  are  to  use  them. 

Materials  for  Construction. — A  large  number  of  materials  have  been 
used  in  the  construction  of  devices  for-  the  regulation  of  teeth.  Gold, 
silver,  platinum,  platinous  gold,  platinous  silver,  iridioplatinum, 
platinoid,  aluminum,  nickel  silver,  brass,  copper,  aluminum  bronze, 
steel,  iron,  vulcanized  rubber,  India  rubber,  wood,  silk,  hemp,  gut,  and 
many  combinations  of  these  materials  have  all  been  used.  None  are 
ideal,  yet  most  of  them  possess  properties  of  more  or  less  value.  After 
years  of  experimenting  the  writer  is  convinced  that  the  material  most 
nearly  filling  all  requirements  is  high  grade  nickel  silver.^ 

Since  its  introduction  by  the  writer,  in  1887,^  for  the  construction  of 
regulating  appliances,  it  has  largely  supplanted  all  other  metals  for 
this  purpose.  Owing  to  its  excellent  qualities,  as  well  as  its  inexpensive- 
ness,  nickel  silver  has  been  an  important  factor  in  the  remarkable 
progress  that  orthodontia  has  made  in  recent  years.  Its  great  practical 
value  becomes  more  and  more  apparent  with  familiarity  in  its  use.  It  is 
very  susceptible  of  skilful  working,  and  may  be  developed  to  possess 
great  strength  and  rigidity,  or  it  may  be  given  great  elasticity,  and  when 
properly  annealed  it  is  very  malleable.  Rolled  into  a  flat  ribbon,  it  may 
be  drawn  by  the  band-forming  pliers  so  tightly  about  a  tooth  as  to  con- 
form to  its  surface  with  great  accuracy,  on  account  of  its  properties 
which  permit  of  slight  stretching,  in  striking  contrast  to  gold  or  platinum, 
and  even  though  it  be  but  three-thousandths  of  an  inch  in  thickness,  it 
will  be  sufficiently  rigid  to  withstand  driving  to  place  upon  the  tooth 
without  crimping  or  changing  form,  if  care  be  used. 

Its  surfaces  are  readily  united  by  solder,  and  its  fusing-point  is  so 
high  that  any  of  the  various  grades  of  gold  or  silver  solder  may  be 
employed  without  injury  to  the  band  if  only  the  requisite  amount  of 
heat  be  used. 

It  is  so  slow  a  conductor  of  heat  that  the  excellent  method  of  soldering 
by  holding  many  of  the  pieces  with  the  fingers  may  be  employed,^ 
again  in  sharp  contrast  to  the  other  metals  we  have  enumerated. 

It  is  susceptible  to  a  high  degree  of  polish,  which  should  always  be 
given  to  plain  bands  after  setting,  and  which  is  lasting  in  many  mouths. 
Often  these  bands  will  assume  a  delicate  bronze-like  color,  pleasing  in 
appearance,  and  the  writer  has  known  of  their  being  worn  continuously 
for  three  years  with  no  change  of  color.  In  a  small  percentage  of  mouths, 
however,  they  do  become  discolored,  even  to  unsightliness.  This  fact 
has  given  rise  to  the  only  worthy  prejudice  we  know  of  against  the  use  of 

^  Nickel  silver  is  an  alloy  of  copper,  nickel,  and  zinc,  prepared  in  varying  pro- 
portions, according  to  the  use  for  which  it  is  intended.  The  inferior  grades  con- 
tain iron  and  only  a  low  percentage  of  nickel. 

^  Angle,  Archives  of  Dentistry,  1888. 

'  Introduced  by  the  writer  in  the  first  edition  of  his  work  entitled  the  Angle 
System  of  Regulation  and  Retention  of  the  Teeth. 


742  ORTHODONTIA 

nickel  silver  for  refjulatitif];  appliances;  hut  this  objection  is  trivial  in  view 
of  its  many  points  of  superiority  and  if  the  orthodontist  will  use  the  proper 
quality  of  nickel  silver  and  obey  the  demands  of  modern  ]>rojdiylaxis, 
insisting  on  a  reasonable  degree  of  cleanliness  on  the  part  of  the  patient, 
and  occasionally  devesting  a  few  moments  of  attention  to  the  cleansing 
of  appliances  and  teeth  himself  with  the  soft-rubber  disk  and  jjuinice, 
as  he  should,  no  matter  what  metal  is  used  for  the  appliances,  there 
will  be  little  occasion  for  complaint. 

Another  valuable  property  of  nickel  silver  is  that  it  is  less  liable  to 
injure  the  enamel  of  teeth  when  worn  in  contact  with  it,  than  are  any 
of  the  precious  metals. 

Notwithstanding  the  valuable  qualities  of  nickel  silver,  the  precious 
metals,  as  gold,  platinum,  and  iridium,  are  still  preferred  by  a  few  practi- 
tioners on  account  of  their  greater  resistance  to  oxidation.  Yet  they  are 
by  no  means  free  from  this  fault,  as  it  is  necessary  to  alloy  them  with 
base  metals  in  order  to  gain  the  proper  elasticity.  Yet  when  properly 
alloyed  they  are  sufficiently  free  from  oxidation  for  the  necessary  use, 
and  it  is  probable  that  in  some  mouths,  for  appearance'  sake,  they  are 
more  desirable  than  nickel  silver,  especially  as  retaining  devices  that 
are  to  be  W'Orn  a  long  time  upon  the  teeth. 


THE  WRITER'S   APPLIANCES 

When  the  writer  first  brought  out  his  so-called  system  of  appliances, 
malocclusion  was  yet  unclassified,  and  the  "special  appliance  for  each 
case"  method  of  treatment  was  the  only  one  taught  or  practised.  In 
an  attempt  to  reduce  to  something  like  system  and  order  the  chaos  of 
regulating  appliances  that  cumbered  the  literature  and  hindered  the  prog- 
ress of  orthodontia,  these  appliances,  designated  as  sets  Nos.  1  and  2,  with 
a  few  auxiliary  parts,  numbering  some  twenty  in  all,  were  introduced. 

By  their  use  separately  and  in  comlnnations  it  was  presumed,  and 
truly,  that  tooth  movements  could  be  much  more  quickly  and  easily 
performed,  and  with  far  less  annoyance  to  the  patient,  than  by  means 
of  the  necessarily  crude,  clumsy,  and  frequently  very  inadecjuate  hand- 
made metal  devices,  or  the  far  more  undesirable  and  most  unclean  vul- 
canite plates,  cribs,  etc.  With  the  greater  development  of  the  science, 
however,  and  especially  since  the  classification  of  malocclusion,  the 
writer  has  gradually  dispensed  with  the  greater  part  of  even  these  few 
appliances,  until  at  the  present  time  he  uses  practically  but  one,  or  three 
modifications  of  a  single  principle.  This  principle  was  given  us  nearly 
two  hundred  years  ago  by  the  famous  French  dentist,  Fauchard,^  and  it 
has  since  been  used  in  many  modified  forms.     It  is  now  known  as  the 

'  Le  Chirurgien  Dentiste  ou  Traitt'  dcs  Dents,  Paris,  1728. 


THE   WRITER'S  APPLIANCES 


743 


expansion  arch,  and  in  conjunction  with  chunp-hands  for  the  anchor 
teeth,  and  the  auxiharies  of  phiin  or  spurred  l)ands,  and  wire  and  rubber 
Hgatures,  it  is  adecjuate  for  all  necessary  movements  of  all  teeth  in  each 
arch  separately,  as  in  Class  1  eases,  or  for  the  simultaneous  movement 
of  all  teetii  in  both  arches  when  used  in  connection  with  the  Baker 
anchorage,  as  in  cases  belonging  to  Classes  II  and  III. 

The  writer's  improvements  of  this  appliance  may  briefly  be  said  to 
consist  in  change  of  metal  (nickel  silver),  modification  of  form  and  pro- 
portions, delicacy  of  temper,  greater  length  of  threading  of  sides  for 
universal  adjustment  of  size,  in  the  material,  original  patterns,  and  pro- 
portions of  the  anchor  clamp-bands,  and  in  the  various  attachments, 


Fig.  759 


some  of  which  are  modified  and  others  newly  devised.  Important 
among  these  is  the  addition  to  the  clamp-bands  of  the  long  tubular  sheaths 
for  the  reception  of  the  ends  of  the  arch,  which  not  only  protect  the 
cheeks  from  abrasion  by  the  threaded  portion  of  the  arch,  but  give 
greater  stability  to  the  anchorage.  Still  others  deemed  very  important 
are  the  friction  sleeve  of  the  sheath  of  the  clamp-bands  and  extension 
flange  of  the  arch  nuts,  the  extension  rib  on  the  ribbed  arch,  the  sheath 
hooks,  for  use  in  the  Baker  anchorage,  and  last  and  most  important,  the 
brass-W'ire  ligatures,  descriptions  of  all  of  which  follow^  in  connection 
with  instructions  for  their  use. 

As  before  stated,  there  are  three  forms  of  the  expansion  arch.     Fig. 
759  represents  the  plain  expansion  arch  E,  w^hich  is  a  ver3^  elastic  round 


744 


ORTHODONTIA 


bar,  bent  to  conform  jipproximatcly  to  the  sliaj)!^  of  an  ideal  dental  arch. 
The  sides  of  this  arch  are  threaded  and  provided  with  nuts,  which,  with 
the  threaded  portion  of  the  arch,  accurately  fit  the  smooth-bore  tubes  of 
the  X  and  D  bands.  One  end  of  these  nuts  is  elon<]jated  to  form  an 
extension  flange,  which  accurately  telescopes  the  friction  sleeve  of  the 
sheaths  of  the  D  and  X  bands,  as  shown  in  the  engraving. 

This  form  of  nut  adds  another  truly  valuable  improvement  to  the  ex- 
pansion arch,  as  it  enables  us  to  make  the  exposed  part  of  the  nut  very 
short  and  compact,  at  the  same  time  giving  greater  length  of  thread 


Fig.  V60 


and  consequently  greater  strength.  Its  greatest  value,  however,  is  that 
this  extension  flange  prevents  the  loosening  of  the  nut  by  unscrewing 
from  friction  with  the  tongue  or  cheek — a  common  annoyance  since 
screw  devices  have  been  used  in  the  mouth,  and  for  this  purpose  it  is 
ideally  simple  and  efficient.  This  improvement  is  also  made  use  of 
in  the  writer's  jack-  and  traction-screws. 

Fig.  760  shows  the  ribbed  expansion  arch  E,  a  later  modification  of 
the  arch  last  shown,  and  differing  from  it  only  in  that  it  is  provided  with 
a  delicate  rib  on  the  periphery  of  the  unthreaded  portion,  in  which  hook- 
like notches  are  to  be  made  at  desired  points  to  prevent  slipping  of  the 


THE    WlilTEWS  AI'I'LIANCES 


745 


wire  ligatures,  liy  this  means  the  direetioii  of  force  on  the  moving  teeth 
is  accurately  controlled.  The  rib  also  adds  force  to  the  arch  for  lateral 
expansion.    It  is  a  most  important  improvement. 


Fio.  7(il 


Fig.  761  shows  the  third  form  of  the  arch,  as  used  by  the  writer, 
known  as  the  arch  B.  It  is  a  smooth,  threadless  arch,  similar  in  form 
and  temper  to  the  plain  expansion  arch  E,  though  more  limited  in  use. 
It  is  especially  designed  for  use  in  connection  with  the  Baker  anchorage, 
having  a  sheath-hook  on  each  side  for  the  reception  of  the  rubber  liga- 
tures. 

Fig.  762 


These  little  sheath-hooks.  Fig.  762,  may  also  be  obtained  separately 
for  attachment  to  either  of  the  other  arches  whenever  it  may  be  desired 
to  employ  them  in  connection  with  the  Baker  anchorage. 


Fig.  763 


Fig.  763  represents  six  adjustable  clamp-bands.  Nos.  1  and  2  are 
plain,  and  are  used  both  for  tooth  movement  and  in  retention.  Nos. 
3  and  4  are  provided  with  strong-headed  pins  soldered  to  their  screw- 
heads.  These  were  especially  designed  for  the  treatment  of  fractures  of 
the  maxillae.  1 

*  For  a  consideration  of  this  subject  the  student  is  referred  to  the  sixth  edition  of 
the  writer's  work  on  Malocclusion  of  the  Teeth  and  Fractures  of  the  Maxillae. 


74() 


ORrilODONTIA 


The  X  and  D  bands  air  j)rovid('d  witli  sinooth-hore  tiihes  soldered 
to  their  sides,  into  which  the  ends  of  tlie  arches  and  the  extension  Han^e 
of  the  nuts  accurately  fit.  The  X  l)ands  are  for  bicuspids  and  the  I) 
bands  for  molars/ 

Fi<r.  7()4  shows  three  coils  of  band  material  from  which  plain  bands 
for  incisors,  canines,  or  even  premolars  may  be  made,  to  serve  as  mediums 


Fk;.  7(i4 


# 


of  attachment  to  the  arch  through  the  wire  ligatures.  They  also  are 
very  largely  used  in  retaining  devices.  C  and  F  are  of  the  same  width, 
being  narrower  than  H,  and  F  and  H  are  of  the  same  thickness,  being 
thicker  than  C.  C  is  used  only  when  a  very  thin,  delicate  band  is 
recjuired.  F  is  used  where  a  stronger  band  is  needed,  and  has  much 
more  universal  use.    H  is  used  principally  for  canine  bands. 

Fig.   765 


Fig.  765  represents  the  wire  (7,  a  section  of  very  soft,  smooth  wire. 
For  the  making  of  spurs  on  bands  for  the  attaching  of  ligatures,  or  for 
retention,  it  is  indispensable.  It  is  also  used  for  reinforcing  anchorage, 
and  for  the  moving  of  teeth  in  a  novel  way,  the  latter  being  illustrated 
in  Fig.  829.     The  size  of  this  wire  to   be  most  universal  of  use  was 

'  For  the  varying  sizes  of  molar  teeth  are  three  sizes  of  D  bands,  although  in 
the  writer's  practice  the  medium  size  alone  meets  nearly  all  reciuiremcnts  of  the 
permanent  molars.  The  smaller  size,  liowever,  is  occasionally  demanded  on  de- 
ciduous molars. 


THE   WRITER'S  APPLIANCES 


747 


decided  upon,  after  much  thouoht  aud  experimenting,  to  be  forty-two 
thousandths  of  an  inch  in  diameter.  Yet  for  the  making  of  smaller 
spurs,  and,  occasionally,  later  forms  of  retaining  devices,  a  wire  of 
smaller  diameter  has  proved  advantageous.  So  the  writer  has  recently 
added  two  smaller  sizes,  one  twenty-nine  thousandths  of  an  inch  in 
diameter  and  the  other  twenty-two  thousandths  of  an  incli  in  diameter. 
These  are  both  of  precious  metal. 


Fig.  766 


/ 


a 


Fig.  766  represents  the  retaining  tubes  i?,  which  are  used  in  detach- 
able connections,  in  reinforcino-  anchoraee,  in  retention,  etc. 

Fig.  767  represents  the  brass  ligature  wire,  which  is  very  soft,  smooth, 
tough,  strong,  bright  wire,  especially  prepared  for  the  use  of  orthodon- 
tists.   Three  sizes  meet  all  requirements. 


Fig.  767 


Fig.  768  represents  strips  of  rubber  used  by  stretching  between 
tooth  and  arch,  or  between  ligature  and  tooth,  then  cutting  off  the  super- 
fluous ends,  as  in  Fig.  SOS.  In  this  way  force  is  made  more  continuous 
and  the  time  for  tooth  movement  shortened.  In  like  manner  the  strips 
of  rubber  are  used  with  great  advantage  to  assist  in  rotating  very  obstinate 


Fig.  768 


yS  IM,   WIDE 

lias 


3/16  IN.    v.'  I  D  E 


teeth,  as  shown  in  Fig.  769  and  770.  The  figures  just  referred  to  and 
Fig.  807  all  show  working  combinations  of  the  writer's  appliances  just 
described. 

The  following  appliances  are  those  which  the  writer  has  now  practi- 
cally eliminated  from  his  practice,  not  because  they  were  inefficient  to 


748  ORTllODONriA 

perform  the  tooth  movements  required  of  them,  but  because  they  were 
designed  to  act  locally,  so  to  speak,  or  only  upon  teeth  that  seemed 

Fir,.  709 


l£.H.  A. 


"crooked,"  instead  of  to  operate  from  the  basis  of  occlusion,  and  having 
control  of  one  tooth  or  of  all  teeth  in  one  or  both  arches.     But,  as  will 


Fig.  770 


be  shown  later,  while  not  often  used,  they  are  still  so  necessary  for 
some  purposes  that  they  cannot  be  wholly  dispensed  with.  Their  uses 
will  ])e  described  later. 


THE   WRITER'S  APPLIANCES 


749 


Fig.  771  sliows  the  jack-screw  E  and  J.  The  first  regulating  jack: 
screw  was  invented  by  Dr.  Dwindle,  of  New  York,  in  1848.  Tlii- 
invention  marked  two  important  steps  in  the  progress  of  this  sciences 
(1)  The  introduction  into  orthodontia  of  one  of  the  most  compact  yet 


Fi.;. 


iwmmmmmmmmmmimm 


powerful  forms  of  mechanism  known  to  mechanics  for  exerting  force; 
(2)  the  lieginning  of  fixed,  standard  forms  of  regulating  appliances, 
with  interchangeable  parts,  and  kept  in  stock  at  the  dental  supply 
houses.^ 


Fig.  772 


Fig.  772  shows  the  traction-screw  A  and  D.  It  consists  of  a  shaft 
bent  sharply  at  right  angles  at  one  end,  the  other  end  threaded  and 
provided  with  an  extension  flange  nut  and  three  accurately  fitting  tubes 


Fig. 


of  smooth  bore — one  long  one  with  friction  sleeve  for  the  accommoda- 
tion of  the  extension  fiange  of  the  nut,  and  two  short  ones,  D.  Since 
in  treatment  the  sacrifice  of  teeth  has  become  rarely  necessary,  the 


Fig.  77-t 


use  for  this  once  highly  regarded  appliance  is  greatly  limited,  yet  it 
is  still  valuable  on  rare  occasions. 

'  The  writer's  jack-screw  was  invented  in  1886.       Transactions  Ninth  Inter- 
national Medical  Congress. 


750 


ORTHODONTIA 


Fi^.  773  shows  a  hundle  of  sprint;  levers,  of  four  different  sizes. 
Tliese  are  made  of  piano  wire,  on  aeeount  of  its  superior  elastieity; 
yet  because  of  the  liability  of  steel  to  corrode,  no  matter  how  heavily 
plated,  its  ordinary  use  is  objectionable.  These  levers  may  also  be 
made  of  nickel  silver  or  of  a  combination  of  gold  and  iridioj)latiimm. 


Fig.  775 


The  traction  bar  A,  Fig.  774,  is  provided  Avith  a  standard  in  its  centre, 
Avhich  has  a  socket  for  the  reception  of  a  delicate  ball  on  the  centre 
of  the  arch  B.  The  hooked  ends  of  this  bar  are  for  the  reception  of 
heavy  elastic  bands  from  the  headgear,  as  shown  in  Fig.  775. 

The  headgear,  Fig.  776,  is  a  cap  of  silk  netting  laced  to  a  metal  rim 
and  covering  the  back  of  the  head,  for  the  even  distribution  of  force 


THE   WRITER'S  APPLIANCES 


751 


exerted  by  t\w  hciivy  elastic  hands.  Tliis  cap  is  strong,  artistically 
made,  and  is  very  neat  in  appearance.  The  rim  is  non-collapsible  and 
may  he  easily  and  quickly  adjusted  to  fit  any  size  of  head. 


Fig.  776 


ET.H.A 


The  traction  bar  and  headgear  still  embrace  the  best  principles  in  the 
application  of  occipital  anchorage,  but  in  their  use  the  relinquishment 
and  reapplication  of  pressure  is  necessarily  frequent,  and  this  is  always 
an  objectionable  feature,  being  the  most  potent  cause  of  inciting  inflam- 
mation in  tooth  movement.     So  it  is  for  the  best  of  reasons  that  they 


Fig.  777 


have  largely  given  place  to  the  more  rational  method  of  applying  force 
by  means  of  the  Baker  anchorage.  They  cannot  yet  be  wholly  dis- 
pensed with,  for  it  is  occasionally  very  advantageous  to  apply  force  in 
this  way  as  auxiliary  to  the  Baker  anchorage. 


752 


ORTHODONTIA 


The  chin  retractor,  Fig.  777,  is  made  of  aluminum;  itishght,  neat,  and 
highly  ]K)li.shed.  It  will  fit  in  all  cases,  as  it  is  only  necessary  that  the  fit 
be  approximately  accurate.  A  layer  of  fresh  absorbent  cotton  should 
always  be  placed   between   metal   and   chin   each   time  it  is  adjusted. 


Fio.   778     Fig. 


Fig.  7sn 


Fig.   7X1 


Used  with  the  headgear,  as  shown  in  Fig.  777,  it  was  formerly  our  chief 
reliance  for  the  treatment  of  cases  belonging  to  Class  III,  but  its  use, 
also,  has  been  practically  superseded  by  the  Baker  anchorage,  yet  it 
will  doubtless  continue  to  be  a  valuable  auxiliary  to  the  Baker  anchorage 


in  rare  cases. 


THE   WRITER'S  APPLIANCES 


753 


Tools. — For   uniting'    tlie   cliii'erent   parts   of   the   appliances   to   form 
the  various  combinations,  and  for  placing  them  in  position  upon  the 


Fig.  7S2 


Fir..   783 


teeth,  only  a  few  tools  are  necessary,  but  it  is  important  that  they  should 
be  of  the  best  selection  and  some  of  them  of  special  design. 

Fig.  778  shows  the  writer's  soldering  pliers.    Their  delicate  proportions 

48 


754 


ORTIIODOXriA 


and  peculiar  form  make  them  osjx'cially  suited  for  holding;  hands  'while 
soldering,  as  Avell  as  otiier  j^ieees  of  the  a})pliances. 

Fig.  779  shows  anotiier  ])air  of  pliers,  for  placing  pieces  of  solder  in 
position,  picking  up  small  pieces,  etc. 


Fir,.   785 


Fir..   7S6 


The  writer's  liand-forming  pliers  are  shown  in  Fig.  7S0.  These 
were  designed  especially  and  are  indispensable  for  band-making.  They 
also  are  very  useful  for  most  other  purposes  for  which  ordinary  flat- 
beaked  pliers  are  used,  and  are  provided  with  grooves  for  holding  the 
small  square  nuts  and  round  wire. 


TJJE   WlilTER'S  APPLIANCES  755 

A  good  pair  of  wire  cutters  is  essential.  The  style  shown  in  Fig. 
781  is  the  most  satisfactory  of  the  many  makes  that  the  writer  has  tried. 

The  writer's  regulating  pliers  are  shown  in  Fig.  782.  With  them  any 
necessary  degree  of  force  may  be  applied  for  the  movement  of  teeth  in 
a  novel  manner,  illustrated  in  Fig.  783,  In  no  other  way,  not  even 
excepting  the  wedge,  is  force  exerted  in  so  compact  a  manner,  and  yet 
the  degree  of  force  is  under  the  most  perfect  control.  AYhile  the  range 
of  application  of  this  method  of  applying  force  is  not  great,  yet  on  account 
of  its  simplicity  it  is  extremely  valuable  in  widening  the  anterior  part  of 
the  arches  of  very  young  children,  as  shown  in  the  illustration. 

A  section  of  wire  which  has  been  softened  and  pointed  at  each  end 
is  made  to  rest  in  pits  in  the  enamel  of  the  deciduous  canines.  The 
movement  of  the  teeth  is  effected  by  lengthening  this  wire  by  an  occasional 
pinch  from  the  regulating  pliers.  These  pliers  should  never  be  used 
on  hard  wire. 

This  instrument  is  also  valuable  in  many  other  ways,  especially  in 
modifying  the  form  of  retaining  devices  without  the  necessity  of  their 
removal. 

The  flattened  portion  of  the  very  poTverful  beaks  make  it  ideal  for 
giving  temper  to  softened  wire  through  slightly  flattening  the  wire. 

The  writer  also  uses  it  with  much  satisfaction  as  a  hand  vise. 

Decidedly  the  most  convenient  form  of  scissors  for  trimming  bands, 
clipping  ligatures,  etc.,  is  shown  in  Fig.  784. 

The  How  pliers,  for  twisting  ligatures  and  for  general  uses,  is  shown 
in  Fig.  785. 

An  ordinary  hand  mallet  and  band  driver  (shown  in  Figs.  786  and 
787)  are  also  requisite.  The  flat  end  of  the  band  driver,  as  here  showm, 
has  too  long  a  bevel.  It  should  be  shorter  and  more  nearly  at  right 
angles,  so  as  not  to  cut  the  bands,  and  occasionally  roughened  with  a 
fine  file  to  prevent  slipping.  The  round  end  is  for  restoring  the  form 
to  the  ends  of  the  tubes  of  the  anchor  bands  when  accidentally  bent. 

The  two  wrenches  shown  in  Figs.  788  and  789  are  of  universal  appli- 
cation to  all  the  various  nuts  of  the  appliances;  one,  a  single-end  w^rench, 
and  the  other  a  double-end,  or  right-and-left,  wrench  especially  designed 
for  the  adjustment  of  nuts  of  the  clamp-bands  on  lower  molars,  they 
being  practically  inaccessible  to  the  use  of  a  straight  WTench.  Both 
are  made  of  steel,  nickel-plated,  and  finely  finished. 

And  very  important  is  a  suitable  blowpipe  for  soldering.  The 
writer  prefers  the  one  shown  in  Fig.  790,  the  invention  of  a  former 
student  of  his.  Dr.  Jos.  Griinberg.  It  has  a  very  delicate  fiame,  and 
may  be  quickly  adjusted  to  any  desired  angle  or  height. 

Dr.  Oppenheim,  also,  has  added  another  useful  tool  to  those  already 
enumerated,  for  use  in  connection  with  the  writer's  appliances.  It  is 
illustrated  in  Fig.  791,  and  is  for  the  purpose  of  grasping  a  screw  or 
piece  of  wire  and  firmly  holding  it  at  any  desired  angle  w^hile  it  is 


756 


Fig.  787 


ORTHODONTIA 
Fig.  7S8 


Fig.   7S0 


Sy 


FiQ.  790 


SOLDERING 


757 


being  soldered  or  filed.  Fig.  7!)2  shows  a  finely  tempered  steel  instru- 
ment, devised  by  Dr.  Griinberg,  that  has  been  turned  to  exactly  fit  the 
bore  of  the  friction  sleeve  of  the  tubes  of  the  X  or  D  bands — very 
useful  in  effecting  the  proper  alignment  of  these  tubes  when  fitting 
the  bands  to  the  teeth. 


Fig.  791 


Fici.   792 


^1 


SOLDERING 


It  is  safe  to  say  that  no  one  will  ever  attain  proficiency  in  orthodontia 
unless  he  acquires  much  skill  in  soldering,  for  the  soldering  of  bands 


758 


ORTHODONTIA 


and  the  union  of  tubes  and  spurs  to  bands  is  of  such  frequent  necessity 
that  skill  in  the  work  is  highly  essential.  Krt'orts  have  been  made  by 
some  to  construct  regulating  and  retaining  appliances  so  that  all  unions 
of  parts  shall  be  effected  by  mechanical  attachments,  as  screw-,  hook-, 
or  clamp-joints.  But  to  the  thoughtful  observer  it  would  retjuirc  no 
argument  to  prove  that  such  attachments,  beyond  certain  narrow  limits, 
are  impracticable,  and  that  a  brazed  joint  is  far  stronger,  far  more 
compact,  cleanly,  and  inexpensive. 

As  many  of  the  parts  of  these  appliances  are  very  delicate,  it  is  important 
that  a  fine,  sharp,  steady  flame  be  used  in  effecting  their  imion  by  solder. 
A  large  or  uneven  flame  would  injure  and  might  ruin  them.  The  blow- 
pipe should  be  operated  w  ith  the  ordinary  foot  bellows,  or  automatic 
compressor,  leaving  the  hands  of  the  operator  free. 


Fig.  793 


Fig.  794 


The  plan  of  soldering  introduced  by  the  writer  in  1SS7,  of  holding  the 
pieces  in  contact  with  each  other,  in  the  flame  at  the  desired  point  with 
the  fingers  or  pliers,  avoids  completely  the  time  and  trouble  necessary 
for  investing  the  pieces,  or  wiring  them  together,  as  formerly.  The 
metal  of  which  these  appliances  are  made  is  most  favorable  for  solder- 
ing in  this  way,  it  being  so  poor  a  conductor  of  heat  that  most  of  the 
attachments  can  be  held  in  the  fingers  without  any  perceptible  com- 
munication of  heat  to  them,  provided  the  flame  is  suitable. 

When  union  of  a  small  tube  with  a  band  is  desirable,  as  in  Fig.  793, 
the  tube  is  best  held  in  contact  with  the  band  and  flame  by  means 
of  some  delicate  instrument  that  will  absorb  l)ut  litde  heat.  One  of 
Gates'  nerve  drills  with  the  point  broken  off  is  nearly  ideal  for  this 
purpose.  When  two  small  tubes  are  to  be  united,  as  in  Fig.  794,  pliers 
may  be  used  for  supporting  one  of  them. 

This  method  of  soldering  is  not  difficult,  most  students  learning  it 
readily.  The  only  point  that  may  seem  at  all  difficult  to  the  beginner 
is  the  holding  of  the  pieces  in  fixed  position  just  at  the  time  the  solder 
is  congealing.     This  is  accomplished  by  touching  one  or  more  of  the 


SOLDERING  759 

fingers  of  one  hand  with  those  of  the  ojjposite  liand,  as  in  Figs.  793 
and  794,  to  steady  them,  at  the  same  time  holding  the  pieces  genUy,  not 
rigidly,  just  as  a  good  penman  holds  a  pen.  After  a  little  practice 
any  of  the  various  soldered  attaclnnents  may  be  easily  and  quickly 
made. 

When  the  end  of  a  small  tube  is  to  be  united  to  a  band,  it  is  best  to 
fuse  the  solder  upon  the  band,  then  hold  the  small  tube  by  means  of  the 
straight  pliers  in  contact  with  the  solder  and  again  apply  heat,  as  other- 
wise the  solder  will  usually  be  drawn  into  the  tube. 

The  solder  best  adapted  for  uniting  the  different  parts  of  these  appli- 
ances is  silver  solder,^  although  any  of  the  various  carats  of  gold  solder 
may  be  used  with  cream  of  borax  for  a  flux.  Never  use  more  solder 
than  is  necessary,  especially  in  all  small  attachments — ^just  enough  to 
make  the  union. 

Always  avoid  overheating.  Apply  just  sufficient  heat  at  the  right 
point  from  a  fine,  sharp  flame  to  thoroughly  fuse  the  solder.  In  every 
instance  avoid  heating  the  screws  or  nuts.  This  is  to  be  especially 
observed  with  the  jack-  and  traction-screws  and  the  arches  E  and  B,  as 
great  care  is  used  in  their  manufacture  to  preserve  their  elasticity  and 
strength,  and  this  fine  temper  would  be  ruined  by  heating. 

Almost  innumerable  clamps  and  springs  have  been  devised  for  hold- 
ing the  pieces  while  soldering,  many  of  them  complicated  and  bulky. 
They  are  entirely  useless  to  him  who  will  devote  a  little  time  to  mastering 
the  plan  of  soldering  above  outlined. 

Making  Plain  Bands. — As  the  plain  bands  form  such  an  important 
part  in  this  system,  it  is  important  that  proper  methods  be  employed  in 
their  making. 

We  have  already  stated  our  reasons  for  preferring  nickel  silver  for 
the  making  of  regulating  appliances,  and  especially  for  the  making  of 
bands;  yet  this  metal  varies  greatly  in  quality,  not  only  on  account  of 
differences  in  the  formulae  from  which  it  is  made,  but  also  on  account 
of  the  manner  of  manipulation  in  manufacture. 

It  is  important  that  it  shall  be  of  the  proper  fineness,  thickness,  and 
temper,  or  it  will  be  harsh  and  unyielding  and  difficult  or  impossible  of 
proper  adaptation  to  the  form  of  the  tooth,  in  which  case  it  will  loosen 
more  readily  under  the  strain  of  tooth  movement,  will  occupy  unneces- 
sary space  between  the  teeth,  and  present  a  less  pleasing  appearance. 

There  is  a  chance  for  the  development  of  real  skill  in  the  making 
and  fitting  of  plain  bands,  and  no  one  can  do  it  successfully  without 
devoting  time  and  study  to  the  technique  of  the  operation. 

Let  it  be  remembered  that  each  coil  of  band  material  must  first  be 
annealed  in  bulk,  by  heating  it  to  a  dull  redness,  before  breaking  the 

'  The  writer  recommends  a  silver  solder  for  the  use  of  orthodontists  by  the  S.  S. 
White  Dental  Manufacturing  Co.  Dr.  Griinberg  has  recently  advised  that  for  con- 
venience the  solder  be  drawn  into  the  form  of  wire — about  18  gauge. 


7GU 


ORTHODONTIA 


wire  encirflinfx  it.  '^riicn,  to  simply  pinch  a  short  j)iece  of  hand  material 
al)out  tlu'  tooth  is  to  make  a  loose,  eriide  fittiii<;  hand,  Fii;.  70().  Pieces 
of  generous  length  should  he  used  and  the  hand  made  over  the  natural 
tooth,  not  over  a  plaster  tooth. 

Another  point  of  great  importance  is  that  the  hand,  in  order  to  fit 
perfectly,  must  be  stretched  about  the  tooth  in  the  making.  This  can 
onlv  be  accomplished  by  slipping  the  loop  of  band  material  around 
the  tooth  to  the  desired  point,  pulling  firmly  on  the  ends  of  the  band 
material  in  one  direction  with  the  thumb  and  fingers  of  one  hand,  while 


Fig.  795 


the  band-forming  pliers  are  pushed  with  ef|ual  force  in  the  opposite 
direction  at  the  same  time  they  are  closed  in  the  act  of  pinching  the 
ribbon  of  metal  about  the  tooth  with  the  other  hand. 

By  this  method  sufficient  pressure  is  brought  to  bear  to  make  it  fit 
with  the  greatest  accuracy  the  surface  of  the  tooth  around  which  it  is 
drawn,  and  if  after  soldering  the  surplus  ends  be  cut  off  .so  they  will  still 
be  united,  as  in  F'ig.  795,  there  will  be  very  little  waste  to  the  strips  of 
band  material,  and  ample  length  for  a  firm  grasp  will  always  be  insured. 
Bv  exercising  the  proper  care  a  considerable  number  of  bands  can  be 
made  from  each  of  the  coils  of  band  material  C,  F,  and  II. 


Fig.  796 


No  one  should  expect  other  than  a  very  crude  band  if  rough  or  loose- 
fitting  pliers  be  used  for  pinching,  for  the  junction  of  the  pinched  por- 
tion will  then  be  rounded,  as  in  Fig.  796,  instead  of  sharp  and  at  right 
angles,  as  in  Fig,  795. 

In  soldering  a  band  a  jjortion  of  silver  solder  about  one-eighth  of  an 
inch  square,  wet  with  borax  cream,  is  placed  between  the  angles  of  the 
band  and  held,  by  means  of  the  band-soldering  pliers,  over  the  flame, 
Fig.  797.     With  these  pliers  uniform  pressure  is  exerted  at  the  exact 


SULDKlilNG 


7G1 


points  nocessary  to  insnr(>  the  scam  being  even  and  perfect,  while  the 
minimum  amount  of  heat  only  is  absorbed  by  the  pliers;  consequently 
no  chanji-e  of  form  or  injury  to  them  is  likely.  A  further  advantage  of 
their  use  is  that  their  pt)ints  rest  in  contact  with  the  band  material  in 
such  position  as  to  be  shielded  from  the  solder,  so  that  none  will  be  fused 
upon  its  points,  thus  avoiding  an  annoyance  of  no  small  moment  that  is 
often  encountered  in  the  use  of  ordinary  pliers,  their  contact  with  the 
solder  being  almost  a  necessity. 

Fig.  797 


To  insure  the  flowing  of  the  solder  in  the  seam  only,  plenty  of  borax 
should  be  placed  there,  but  none  on  the  inner  surface  of  the  band,  as 
otherwise  the  solder  will  be  drawn  from  the  seam  and  there  will  be 
faulty  union  or  a  thickening  of  the  band,  either  of  which  would  render 
it  entirely  useless.  When  soldered  the  band  should  present  a  continu- 
ous, even  inner  surface.  Any  other  union  is  imperfect  and  is  ample 
cause  for  condemning  the  band.  The  band  being  properly  fitted,  it  is 
ready  for  any  attachments  which  may  be  required. 


Let  us  again  insist  upon  the  importance  of  a  very  hot,  fine,  sharp- 
pointed  flame  in  the  making  of  all  these  attachments,  as  neatness  in 
such  delicate  soldering  is  impossible  with  a  coarse  flame. 

The  principal  soldered  attachments  to  the  plain  bands  are  tubes  R, 
spurs,  and  staples.  The  two  latter  are  made  from  the  wire  G,  as  shown 
in  D,  E,  G,  and  H,  Fig.  798,  and  B,  Fig.  807. 


762 


oirrnoDosTiA 


The  attachment  of  a  spur  is  best  accompHshed  by  lieating  the  smootlied 
end  of  the  wire  G,  touching  it  to  a  hirge  piece  of  l)orax,  and  holdintr  it 
in  contact  with  a  small  piece  of  solder  in  the  flame  until  it  is  partially 
fused,  then  bringin^^  it  in  contact  with  the  band  at  the  desired  point  and 
again  holding  it  in  the  flame.  After  it  is  fused  (Fig.  799)  it  is  clipped 
off  to  the  desired  length,  which  should  never  be  but  slightly  greater  than 
the  diameter  of  the  ligature  which  is  to  engage  it,  and  the  roughened 
ends  made  smooth  with  a  file.  But  little  solder  should  be  used,  as 
a  large  amount  would  form  an  incline,  which  would  not  so  well  hold 
the  ligature. 

If  a  staple  is  to  be  made,  the  end  of  the  wire  is  bent  into  the  form  of 
the  letter  U,  the  solder  is  flowed  upon  the  surface  of  the  band  first,  then 
the  convex  portion  of  the  staple  is  held  in  contact  and  the  solder  re-fused, 
after  which  the  ends  are  clipped  to  about  one-sixteenth  of  an  inch 
in  length  and  smoothed  with  a  file,  as  in  E  and  H,  Fig.  798.  The  jaws 
of  the  staple  should  closely  fit  the  piece  they  are  to  engage. 

Fig.  799 


When  an  oval  loop,  as  in  D  and  (7,  Fig.  798,  is  to  be  attached,  the 
solder  should  be  flowed  first  upon  the  band,  and  only  in  sufficient 
quantity  to  secure  the  loop  at  the  given  point.  A  larger  amount  is 
unnecessary,  and  might  be  drawn  into  the  cavity  of  the  loop. 

It  is  desirable  that  all  attachments,  both  for  moving  the  tooth  and  in 
anticipation  of  retention,  shall,  if  possible,  be  made  before  first  setting 
the  band,  in  order  that  the  pain  and  troul)le  of  removal  and  substitution 
of  a  new  band,  after  the  teeth  have  become  tender,  may  be  avoided. 

The  untrimmed  ends  of  the  band  serve  the  useful  purpose  of  a  handle 
for  holding  it  in  the  flame  and  in  contact  with  the  piece  to  be  attached, 
as  in  G  and  H,  Fig.  798,  and  Fig.  799.  After  the  attachments  have 
been  made  the  ends  of  the  bands  are  trimmed  off,  leaving  them  long  or 
short,  as  desired.  If  a  niche  Is  to  l)e  formed  to  engage  some  other  appli- 
ance, the  ends  are  left  about  one-sixteenth  of  an  inch  long,  as  in^I,  Fig. 
798;  but  if  they  are  not  to  serve  as  a  means  of  attachment  they  may 
be  trimmed  still  shorter,  although  it  is  never  desirable  to  trim  them  even 
with  the  surface  of  the  band.    The  sharj)  corners  should  be  rounded. 


SOLDERING 


763 


The  canine  is  the  most  difficult  of  any  of  the  teeth  to  band,  but  l)y 
forniiniT  the  seam  on  the  Hngual  incHne  instead  of  on  the  labial,  and 
firmly  burnishing  the  outer  surface  while  it  is  being  pinched,  an  accurate 
fit  can  in  most  instances  be  made.  Another  plan  is  to  pinch  a  fold  in  the 
loop  of  band  material  on  the  lingual  incline,  while  the  ends  of  the  band 
material  of  generous  length  are  being  firmly  drawn  with  the  fingers  on 
the  labial  side.  The  band  is  then  removed  and  a  little  solder  flowed 
into  the  fold.  It  is  then  replaced  on  the  tooth,  and  the  seam  made  upon 
the  labial  surface  in  the  usual  way,  as  described  on  page  760.  While 
it  is  slightly  more  difficult  to  make  a  band  by  forming  the  seam  on  the 
lingual  surface  of  the  tooth,  yet  its  appearance  is  much  neater  than 
when  the  seam  is  made  on  the  lal:)ial  surface.     It  is  decidedly  easier  to 

Fig.  800 


make  and  fit  bands  made  of  nickel  silver  than  those  made  of  the  more 
unyielding  alloys  of  gold,  iridium,  and  platinum.  Yet,  as  it  is  some- 
times necessary  to  make  them  of  the  latter,  it  is  highly  important  that 
the  proper  skill  be  developed  for  their  proper  making  and  fitting. 

Soft-soldering. — It  is  frequently  necessary  to  attach  sheath-hooks  to 
the  arches  E,  which  are  manufactured  in  such  a  way  as  to  give  them  the 
greatest  possible  amount  of  spring.  If  the  sheath-hooks  are  attached  by 
means  of  the  ordinary  soft  solder  with  which  they  come  provided,  the 
temper  of  the  arches  will  not  be  injured,  provided  only  a  small,  passive 
flame  be  used,  with  just  sufficient  heat  to  melt  the  low-fusing  solder. 

It  is  sometimes  desirable  to  attach  spurs  to  the  plain  arches  E  or  the 
arches  B,  to  prevent  the  slipping  of  the  wire  ligatures,  although  since  the 


7(34  OliTllODOXTIA 

introduction  of  the  ribbed  arch  tliis  necessity  is  largely  obviated.  \\  lien 
spurs  are  used  they  should  be  attached  by  means  of  soft  solder,  in  order 
not  to  injure  the  spring  of  the  arches. 

The  best  plan  for  making  these  spurs  is  to  fuse  a  very  small  piece  of 
this  solder  upon  the  end  of  a  section  of  ligature  wire  (first  having  dipped 
the  end  of  the  wire  in  soldering  fluid),  then  holding  it  in  ccMitact  with 
the  arch  in  the  flame.  This  gives  a  fine  conical  spur  with  brass  centre, 
which  is  very  strong,  yet  inconspicuous.  Fig.  800  shows  the  arch  with 
spurs  both  before  and  after  the  surplus  wire  has  been  cut  off.  The  spur 
need  be  no  higher  than  the  diameter  of  the  ligature  it  is  intended  to 
sup])ort.  If  higher  it  will  abrade  the  lips  or  interfere  with  their 
movements. 

Jeweller's  soldering  fluid  is  used  as  a  flux  in  making  these  attach- 
ments. 

For  a  more  full  and  minute  description  of  the  technique  of  solde  ing 
and  fitting  of  appliances  to  the  teeth  than  is  here  practicable  we  strongly 
recommend  a  most  excellent  treatise  on  the  subject  in  pamphlet  form, 
by  Dr.  Jos.  Griinberg,  procurable  from  the  S.  S.  White  Dental 
Manufacturing  Co. 

ANCHORAGE 

Principles  of  Anchorage. — The  correction  of  the  position  of  a  mal- 
posed  tooth  depends  upon  two  important  things:  first,  that  the  force 
exerted  shall  ])e  from  the  right  direction  and  sufficient  to  efl'ect  the 
movement;  and  second,  that  the  anchorage  shall  be  sufficient  to  resist 
this  force. 

In  the  application  of  force  for  the  movement  of  teeth,  the  crowns 
are  the  only  portions  available  for  efl'ecting  the  necessary  attachments. 
Force  is  usually  exerted  at  right  angles,  or  nearly  so,  to  the  long  axes 
of  their  roots,  and  their  changes  of  positions  may  be  said  to  be  partial  or 
complete. 

In  the  first  instance  the  change  is  principally  in  the  crown  end  of  the 
tooth,  it  being  tipped  into  position,  thereby  changing  its  angle  of  inclina- 
tion, with  little  or  possibly  no  apical  displacement. 

In  the  second  case  the  tooth  is  moved  bodily,  its  coronal  and  apical 
displacement  being  more  or  less  equal,  and  in  the  same  direction. 

Whether  the  movement  shall  he  partial  or  complete  depends  upon  the 
manner  of  attachment,  which  determines  the  distribution  of  the  applied 
force.  In  the  first  instance  the  attachment  must  l)e  in  the  nature  of  a 
hinge  or  pivot,  so  as  to  admit  of  tipping,  as  would  follow  the  use  of  a 
ligature  made  to  exert  force  practically  at  right  angles  to  the  long  axis 
of  the  tooth. 

To  effect  the  second  form  of  movement  necessitates  that  the  attach- 
ment of  the  appliance  to  the  crown  shall  be  rigid,  so  that  tipping  will 
be  impossible,  the  force  being  then  distributed  equally  to  the  root. 


ANCHORAGE  765 

Details  of  Anchorage. — ^As  has  before  been  stated,  there  are  but  seven 
distinct  malpositions  that  teeth  can  occupy.  In  accordance  with  the 
laws  of  physics,  their  movement  into  harmony  with  the  line  of  occlu- 
sion can  only  be  accomplished  by  the  application  of  force  from  a  fixed 
base  of  anchorage  in  one  of  three  ways — pulling,  pushing,  or  twisting. 
As  "for  every  action  there  is  an  equal  and  opposite  reaction,"  it  must 
follow  that  the  same  amount  of  force  will  be  exerted  upon  the  anchor- 
age as  upon  the  tooth  to  be  moved,  and  if  the  anchorage  offer  no  greater 
resistance  than  the  tooth  to  be  moved,  their  equal  displacement  must 
follow. 

For  the  moving  of  teeth  we  have  two  principal  sources  of  anchor- 
age— first,  and  chiefly,  that  which  may  be  derived  from  the  teeth  them- 
selves; second,  that  gained  from  suitable  attachments  to  the  top  and 
back  of  the  head. 

The  resistance  offered  by  different  teeth  varies  greatly  according  to 
their  positions,  size,  length,  and  number  of  roots,  the  direction  from 
which  force  is  exerted,  and  also,  as  we  have  said,  in  the  manner  of  mechan- 
ical attachment. 

Of  the  many  modern  improvements  in  the  methods  of  the  correction 
of  malocclusion,  perhaps  none  have  l)een  greater  than  in  the  devices  for 
securing  anchorage.  The  former  bulky  and  insecure  devices  for  this 
purpose  in  the  form  of  vulcanite  or  metal  cribs  have  become  practically 
obsolete  since  the  perfection  of  the  plain  and  clamp  bands,  which  make 
possible  much  greater  control  of  the  anchorage,  as  well  as  firmness  and 
stability. 

The  force  should  be  as  direct  and  positive  as  may  be  possible  to  secure 
with  the  conditions  at  our  disposal.  The  ideal  anchorage  would,  of 
course,  be  that  from  an  immovable  base.  This,  however,  is  probably 
never  fully  possible  in  the  mouth,  owing  to  the  slight  spring  of  the  alve- 
olar process  and  cushion-like  function  of  the  peridental  membrane. 
Some  displacement  of  anchor  teeth  is  admissible,  and  even  sometimes 
desirable,  provided  they  be  kept  within  the  limits  of  final  restoration  by 
means  of  the  inclined  planes  of  the  occluding  teeth;  but  if  greater  dis- 
placement than  this  take  place,  malocclusion  of  the  anchor  teeth,  most 
difficult  or  even  impossible  to  overcome,  may  be  established.  Hence 
they  should  be  closely  watched  and  careful  measurements  and  com- 
parisons with  the  original  models  be  frequently  made.  Any  unfavorable 
movement  perceived  should  be  promptly  combated.  The  embarrass- 
ment following  any  considerable  displacement  of  the  anchor  teeth  is 
so  serious  that  ample  anchorage  should  alw^ays  be  secured  in  the 
beginning. 

The  available  anchorage  may  be  said  to  be  of  five  kinds.  They  are 
more  or  less  intimately  associated,  and  are  used  in  combinations  or  sepa- 
rately, according  to  the  exigencies  of  requirement.  We  will  designate 
them  as  simple,  stationary,  reciprocal,  occipital,  and  intermaxillary. 


7G6 


ORTHODONTIA 


Simple  nnchornrje  is  that  form  in  wliich  the  resistance  of  the  moving; 
teeth  is  overcome  by  means  of  an  anchor  tooth  or  teeth  of  Uirger  size 
or  more  favorable  location,  the  form  of  attachment  being  hinged  or 
pivotal,  admitting  of  the  tip])ing  of  the  tooth  to  be  moved,  and  the  possible 
tipping  of  the  anchor  tooth.  This  form  of  anchorage,  altliough  often  pri- 
marily unreliable  in  itself,  may  be  reinforced  by  enlisting  the  resistance 
of  other  teeth  in  the  same  arch,  near  or  remote  in  location. 

Stdfioiiary  anchorngc^  is  that  form  in  which  the  attachment  to  the 
anchor  tooth  is  essentially  rigid,  so  that  its  tipping  is  impossible,  and 
if  moved  at  all  it  must  be  dragged  bodily  through  the  alveolar  j)rocess 
in  an  u{)right  position.  Fig.  SOI  shows  an  illustration  of  stationary 
anchorage  to  a  molar  in  the  retraction  of  a  canine.  The  long  sheath 
of  the  screw  is  soldered  to  a  clamp-band  rigidily  cemented  and  clamped 
upon  the  molar,  while  the  angle  of  the  screw  engages  a  tube  soldered 
horizontally  to  a  plain  band  on  the  canine.     The  attachment  to  the 


Fig.  801 


Fig.   802 


canine  is  hinged  and  designed  for  tipping.  Should  any  displacement 
of  the  molar  occur,  both  root  and  crown  would  be  moved  equally  and  in 
the  same  direction.  It  will  thus  be  seen  that  the  resistance  in  this  form 
of  anchorage  is  vasdy  greater  than  in  the  simple  form. 

Skill  and  judgment  are  necessary  in  the  use  of  this  form  of  anchor- 
age, for  its  success  depends,  first,  on  the  absolute  rigidity  of  the  attach- 
ment and  appliance  to  the  anchor  tooth,  and  second,  on  the  amount 
of  force  exerted,  which  must  not  at  any  time  be  so  great  as  to  impair 
the  rigidity  of  the  appliance  or  attachment.  This  is  of  vital  impor- 
tance, for  any  loosening  or  straining  of  the  attachment  would  partially 
or  completely  change  the  anchorage  from  stationary  to  simple. 

Reciprocal  anchorage,  stricdy  speaking,  is  not  a  distinct  form  of 
anchorage,  yet  its  value  and  possibilities  in  application  are  such  that  it 
may  with  propriety  be  so  regarded.    It  is  that  form  in  which  one  malposed 


*  Angle,  Items  of  Interest,  December,  1887. 


ANCHORAGE 


707 


tooth  is  pitted  against  another  in  the  same  arch,  the  tendency  of  the 
force,  correctly  appHed,  being  to  move  both  into  the  Hne  of  occlusion. 

Reciprocal  anchorage  admits  of  the  widest  range  of  application  and 
is  the  most  valual)le  form  of  anchorage.  Each  case  should  be  studied 
carefully  with  a  view  to  its  use  whenever  possible,  either  in  its  simplest 
forms,  as  in  Fig.  802,  or  when  a  greater  number  of  teeth  are  to  be  moved, 
as  in  widening  the  arch  (Fig.  (Sll),  or  in  combination  with  other  forms 
of  anchorage.  It  will  ])e  found  applicable  to  a  very  large  percentage  of 
cases,  and  is  an  important  principle  in  many  of  the  combinations 
of  appliances  to  be  hereafter  shown. 

Occipital  (Dichardge  is  that  form  in  which  the  resistance  is  borne 
by  the  top  and  back  of  the  head  and  transmitted  by  means  of  the  head- 
gear and  heavy  elastics  to  attachments  upon  the  teeth,  as  in  Fig.  775. 
This  well-known  form  of  anchorage,  heretofore  principally  applicable 
in  the  treatment  of  cases  belonging  to  Division  1  and  its  subdivision 
of  Class  II  and  to  Class  III,  has,  since  the  development  of  intermaxil- 
lary anchorage,  been  largely  superseded  by  it. 


Fig.  803 


Fig.  S04 


Intermaxillary  anchorage  is  a  new  form  of  anchorage,  differing  from 
those  already  described  in  that  the  anchorage  or  resistance  to  the  moving 
teeth  is  derived  from  the  teeth  of  the  opposite  arch.  It  may  or  may  noi 
be  used  reciprocally. 

Figs.  803  and  804  illustrate  this  form  of  anchorage  in  cases  in  which 
it  is  not  used  reciprocally,  the  elevation  of  the  upper  canines  being 
accomplished  by  means  of  rubber  ligatures  attached  to  devices  on  the 
lower  teeth,  and  the  lower  teeth  prevented  from  elevating  by  the  irre- 
sistible pressure  of  occlusion.^ 

Fig.  893  shows  a  remarkable  case  which  this  anchorage  was  made 
to  act  reciprocally  in  forcing  the  elevation  of  both  upper  and  lower 
incisors,  canines,  and  premolars.  This  form  of  anchorage  is  direct  and 
powerful,  and  may  often  be  employed  to  much  advantage.  Its  impor- 
tance in  the  modification  now  known  as  the  "Baker  anchoraire"  is  so 
great  as  to  mark  an  epoch  in  the  evolution  of  orthodontia,  for  with  it 


'  This  form  of  anchorage  was  introduced  by  the  writer.     8ee  Dentai  Cosmos, 
1891,  p.  743. 


7G8 


ORTHODONTIA 


the  entire  plan  of  treatment  of  cases  belonging  to  both  Classes  II  and 
III  has  been  revolutionized,  and  instead  of  the  movement  of  the  teeth 
in  these  cases  being  difficult,  as  formerly,  these  cases  have  become, 
by  the  correct  application  of  this  form  of  anchorage,  among  the  easiest 


Fig.  805 


and  most  satisfactory  that  v\e  are  called  upon  to  treat;  that  is,  if  taken 
at  the  proper  age  and  intelligently  managed.  This  form  of  anchorage, 
as  used  by  Dr.  Baker,  is  shown  in  Fig.  805,  and  as  imj)roved  by  the 
writer  is  shown  in  Fig.  806.^ 


Fig.  806 


ADJUSTMENT   AND   OPERATION  OF  APPLIANCES 

Normal  occlusion  is  now  recognized  as  the  working  basis^  of  ortho- 
dontia, and  since  this  recognition  has  necessitated  not  only  the  diagnosis 
of  malocclusion  and  the  art  reciuirements  from  this  basis,  but  prognosis 


»  Soo  Dental  Cosmos,  March,  1903. 

^  Angle,  Malocclusion  of  the  Teeth,  6th  edition. 


ADJVSTMENT  AND  OPERATION  OF  AJTLIANCES         769 

and  lr(>atin(>nf;  as  well.  This  has  made  utterly  useless  many  of  tiie 
thousands  of  appliances  appearing  in  dental  literature  which  were 
desitjned  for  the  treatment  of  individual  cases  from  the  l)asis  of  "alio;n- 
ment"  of  individual  teeth  only,  regardless  of  the  demands  of  the  entire 
denture  from  the  basis  of  the  normal  in  occlusion.  Obviously,  then,  it 
would  be  useless  to  give  here  appliances  and  methods  which  are  now 
obsolete.  Obviously,  too,  it  would  be  useless  to  give  a  number  of 
modern  appliances  which  are  in  fact  but  copies  of  recognized  standard 
forms,  differing  not  in  principle,  but  only  in  individual  matters  of 
detail,  and  differences,  too,  that  often  are  extremely  trivial  and  that 
very  frequently  show  retrogression  rather  than  progress. 

It  has  been  the  constant  aim  of  the  writer  to  reduce  the  number  of 
appliances  and  to  avoid  adding  those  that  were  unnecessary,  well  knowing 
that  a  far  greater  amount  of  skill  may  be  developed  in  the  use  of  a  few 
properly  formed  appliances  or  tools  than  is  ever  possible  with  a  large 
number.  This  is  well  known  among  artisans.  It  is  a  matter  of  regret 
that  the  literature  is  again  gradually  becoming  encumbered  with  instru- 
ments which  add  nothing  to  the  real  progress  of  orthodontia. 

The  appliances  and  plans  of  treatment  which  will  be  here  given 
are  such  as  are  now  recognized  as  the  standard  by  all  the  leading 
orthodontists  of  this  and  other  countries. 

Like  all  pieces  of  mechanism,  regulating  appliances  should  be  judged 
from  the  basis  of  efficiency  and  simplicity,  and  an  ideal  appliance  is 
one  that,  properly  operated,  would  perform  all  necessary  movements, 
whether  lingual,  labial,  mesial,  distal,  of  depression,  elevation,  or 
rotation,  or  their  combinations,  not  only  with  individual  teeth,  nor  of 
the  teeth  of  one  arch  alone,  but  all  movements  required  of  all  teeth 
in  both  arches,  carrying  all  on  simultaneously — one  applicable  to  any 
case  of  any  class,  from  the  simplest  to  the  most  complicated  in  which 
treatment  is  practicable,  and  one  that  should  be  under  the  perfect  control 
of  the  operator,  who  might  hasten  the  movement  of  some  teeth  and 
retard  that  of  others,  as  occasion  might  require,  yet  a  device  so  simple 
as  to  be  easily  comprehended,  and  occasion  the  minimum  amount  of 
inconvenience  to  the  patient.  The  writer  believes  we  at  last  have 
practically  all  of  the  requirements  we  have  enumerated  in  the  appliance 
known  as  the  expansion  arch,  and  shown,  with  its  auxiliaries,  in  Figs. 
769,  807,  and  808. 

This  appliance  is  made  up  of  one  of  the  arches  E,  plain  or  ribbed, 
or  the  arch  B,  anchored  to  the  teeth  by  means  of  the  anchor  clamp- 
bands  D  or  X,  and  used  with  the  auxiliaries  of  plain  or  spurred  bands, 
wire  ligatures,  rubber  wedges,  and  rubber  ligatures,  according  to  the 
requirements  of  the  case.  This  appliance,  in  slightly  varying  com- 
binations, is  practically  the  only  one  now  used  by  the  writer.  Its  great 
value  and  almost  limitless  range  of  possibilities  will  become  more  and 
more  appreciated  in  proportion  as  it  is  studied  and  used, 
49 


770 


ORTHODONTIA 


For  certain  very  simple  movements  of  teeth,  under  suitable  conditions, 
other  forms  of  appliances  which  are  made  to  act  locally  will  he  given 
later. 

Adjustment  of  Clamp-bands. — In  adjusting  this  appliance  the  first 
step  is  the  fitting  of  the  anchor  clamp-hands,  either  L)  or  X.     The  use 


Fir..  807 


of  the  D  bands  on  the  first  molars  is  usually  preferable,  as  these  are  the 
largest  and  firmest  of  the  teeth,  thereby  affording  the  firmest  anchorage. 
Occasions  may  arise,  however,  in  which  it  may  be  desirable  to  adjust 
these  bands  to  the  second  or  third  molars.  The  X  bands  on  the  pre- 
molars, used  on  either  one  or  both  sides,  may  also  sometimes  be  desirable, 
but  their  use  is  only  occasionally  demanded. 


ERA 


In  adjusting  a  clamp-band,  the  nut  should  first  be  loosened  suffi- 
ciently to  allow  aviiple  size  for  the  crown  over  which  the  band  is  to  slip. 
The  band  should  then  be  shaped  between  the  flat  beaks  of  the  band- 
forming  pliers  until  it  conforms  approximately  to  the  shape  of  the  crown 
of  the  tooth,  the  shaft  of  the  screw,  which  should  always  point  forward 
unless  for  some  special  reason,  being  bent  also  if  necessary.    The  band 


ADJUSTMENT  AND  OPERATION  OF  APPLIANCES  111 

should  then  be  worked  carefully  over  the  crown  with  the  fingers  and 
made  to  slide  between  gum  and  enamel  to  the  desired  point,  and  then 
alternately  clamped  and  burnished  until  made  to  conform  accurately 
to  the  shape  of  the  crown. 

One  of  the  greatest  blunders  made  in  adjusting  these  bands  is  to 
trim  or  file  the  band  on  its  edge  in  order  to  prevent  supposed  interfer- 
ence with  the  gums.  Such  procedure  only  ruins  the  band.  Besides,  it 
is  essential  that  this  portion  of  the  band  shall  pass  beyond  the  swell 
of  the  crown  and  be  clamped  and  burnished  to  the  neck  of  the  tooth 
to  prevent  the  band  from  slipping  off.  This  is  the  most  valuable  part 
of  the  band. 

i\.nother  blunder  frequently  made  is  to  begin  the  clamping  or  bur- 
nishing before  the  band  is  well  over  the  crown.  In  this  case  part  of 
the  band  must  bear  the  entire  strain,  and  will  be  stretched  or  torn,  or 
the  band  will  loosen  and  come  off. 

The  screw  must  not  be  allowed  to  project  lingually  to  abrade  or 
interfere  with  the  movements  of  the  tongue.  The  band  should  be 
turned  before  clamping  until  the  screw  is  in  contact  with  the  adjoining 
teeth,  and  after  clamping  it  must  still  be  made  to  lie  in  the  same  position, 
even  though  it  be  necessary  to  bend  the  screw,  as  is  often  required. 

The  bands  are  made  to  endure  the  greatest  possible  strain  consistent 
with  their  nearly  ideal  proportions.  They  will,  therefore,  bear  consid- 
erable tightening  of  the  nut,  yet  if  this  be  carried  too  far  they  will  be 
broken.  It  is  usually  best  not  to  clamp  the  band  too  tightly  at  first, 
but  to  wait  until  the  second  or  third  sitting  for  the  final  clamping  and 
burnishing.  Clamping  of  good  bands  is  ample  to  give  all  needed  firm- 
ness without  cementing,  except  in  efiecting  stationary  anchorage,  as  in 
the  use  of  the  traction  screw,  shown  in  Fig.  801.  Some  orthodontists,  to 
guard  against  the  possible  disintegration  of  the  enamel  underneath  the 
band,  always  cement  it  in  position.  Now,  it  is  a  fact  which  the  writer 
has  verified  in  the  use  of  many  thousands  of  clamp-bands,  that  the 
danger  of  injury  to  the  enamel  from  them  without  cementing  is  prac- 
tically nil,  especially  when  they  are  constructed  from  nickel  silver. 
Formerly  he  always  cemented  them,  but  found  that  in  practice  it  was 
unnecessary  except  in  cases  where  there  was  a  noticeable  tendency  to 
caries  in  the  teeth  of  the  patient.  AVhen  the  band  is  to  be  worn  but  two 
or  three  months  in  healthy  mouths,  it  seems  to  the  writer  that  cementing 
the  clamp-bands  is  a  useless  procedure.  Yet  when  any  doubt  exists, 
it  is  such  a  simple  operation  that  it  is  best  to  follow  the  conservative 
plan  and  cement  them.  In  cases  where  the  band  is  to  be  worn  a  long 
time,  as  in  retention,  there  is  then  no  question  as  to  whether  or  not 
it  should  be  cemented.  Of  course,  plain,  brazed  bands  should,  of 
necessity,  be  cemented  in  all  cases. 

Fig.  809  shows  a  D  band  which  has  been  properly  adjusted  to  the 
crown  of  a  molar.    It  will  be  noted  that  it  accurately  conforrns  to  the 


772 


ORTHODONTIA 


swell  of  the  crown.  A  small  portion  of  the  upper  ed^je  has  heen  bur- 
nished over  the  distal  mariijinal  ridge.  This  is  important  to  prevent  the 
possibility  of  the  band  working  too  far  over  the  crown.  A  band  so 
adjusted  offers  the  firmest  anchorage,  and  cannot  be  loosened  without 
breaking,  or  unturning  the  nut. 

If  the  teeth  to  be  banded  are  crowded,  care  and  patience  are  neces- 
sary to  work  the  band  into  position.  This  is  usually  easy  with  young 
patients,  as  their  teeth  admit  t)f  considerable  movement.  The  band  is 
worked  between  the  teeth  on  one  side  first,  and  allowed  to  remain  for  a 
few  minutes,  then  the  other  side  is  gently  rocked  and  pressed  with  the 
finger,  or,  better,  with  a  flat  piece  of  wood,  until  started  to  place  between 
the  teeth.  It  is  then  w^ell  to  allow  it  to  rest  for  a  few  minutes,  after  which 
sufficient  separation  will  usually  have  taken  place  to  readily  permit  of 
its  further  adjustment. 


Fig.  809 


Fig.  810 


E.  H.  A. 


Where  space  for  the  l)and  cannot  be  thus  readily  made,  a  very  simple 
and  efficient  way  of  providing  it  is  by  means  of  the  writer's  method 
shown  in  Fig.  810,  viz.,  engaging  the  approximating  surfaces  of  the 
adjoining  teeth  with  a  wire  ligature  which  is  tightly  drawn  and  firmly 
twisted  and  the  ends  cut  off.  After  twenty-four  hours  ample  space  will 
have  been  gained. 

It  is  important  that  the  sheath  of  the  clamp  band  shall  be  made  to  line 
accurately  with  the  expansion  arch.  Usually,  with  proper  care  in  fitting 
the  band,  this  is  easily  accomplished.  In  other  cases  slight  bending  of 
the  sheath  to  alignment,  with  the  instrument  made  for  the  purpose, 
shown  in  Fig.  792,  is  permissible.  But  if  there  be  any  considerable 
variation,  as  may  often  be  the  case,  owing  to  the  inclination  of  the  crown 
of  the  tooth  to  be  banded,  the  band  should  be  removed  and  the  sheath 


ADJUSTMENT  AND  OPERATION  OF  APPLIANCES  773 

resoldered  at  the  proper  angle.  This  is  one  of  the  most  simple  opera- 
tions and  the  work  of  hut  a  moment,  carrying  the  band  to  the  flame  by 
holding  the  screw  between  the  jaws  of  the  wire  cutters,  or  with  the  instru- 
ment shown  in  Fig.  791,  and  the  ends  of  the  sheath  by  the  angles  of  the 
band-soldering  pliers,  all  as  shown  in  Fig.  790.  In  like  manner  the  tube 
may  be  shifted  mesially  or  distally — an  occasional  advantage.  The  borax 
flux  must,  of  course,  be  applied  when  soldering. 

Recently  it  has  been  suggested  that  the  sheaths  of  the  clamp-bands 
should  be  self-adjusting  by  having  a  pivotal  attachment  to  the  bands. 
The  utter  absurdity  of  this  is  obvious,  for  the  band  is  thus  weakened 
and  the  firmness  of  anchorage  greatly  impaired,  besides  rendering  the 
appliance  more  bulky  and  less  cleanly. 

Sometimes  after  adjustment  of  the  anchor-band  it  is  found  that  the 
mesially  adjoining  tooth  inclines  buccally  to  such  a  degree  as  to  prevent 
the  passing  of  the  end  of  the  arch  into  the  sheath.  This  is  readily 
remedied  by  unsoldering  the  sheath  from  the  band  and  resoldering 
it,  with  a  piece  of  metal  of  sufficient  thickness  intervening.  Usually 
a  portion  of  a  ten-cent  piece  is  ample.  By  this  means  the  sheath  is 
projected  buccally  sufficient  for  the  ready  insertion  of  the  end  of  the 
arch. 

What  has  been  said  regarding  the  adjustment  of  the  D  bands  will,  of 
course,  apply  to  the  adjustment  of  the  X  and  plain  adjustable  bands  also. 

For  directions  for  cementing  clamp-bands  see  page  783. 

Adjustment  of  Plain  Bands. — Before  adjusting,  the  plain  bands  must  be 
throughly  deoxidized  by  boiling  in  dilute  sulfuric  acid.  The  tooth  to 
be  banded  is  then  cleansed,  dried,  and  protected  from  moisture.  The 
band  is  filled  with  oxyphosphate  of  zinc  of  creamy  consistence,  then 
carried  on  the  end  of  the  finger  to  the  tooth,  upon  which  cement  and 
band  are  pressed.  With  the  fingers  alone  the  band  is  carefully  worked 
nearly  to  the  desired  position,  and  then  driven  down  by  a  few  gentle 
taps  from  the  mallet  and  band-driver.  The  burnisher  is  now  quickly 
applied  to  the  edges  of  the  band  only,  and  the  surplus  cement  wiped 
off.  When  the  cement  has  thoroughly  hardened  the  band  should  be 
polished  and  burnished,  as  it  is  well  known  that  discoloration  is  far 
less  liable  with  a  smooth,  polished  surface  than  with  a  rough  one. 

A  band  made  as  described  in  the  section  on  Soldering,  and  set  as 
above,  will  fit  with  the  most  glove-like  accuracy,  will  present  a  very 
neat  appearance,  and  will  not  loosen  under  necessary  strain.  If  it  is 
defective  in  any  particular,  as  too  large,  weakened  by  crimping,  or 
slightly  torn  when  driven  into  position,  it  should  be  immediately  con- 
demned and  a  perfect  one  substituted,  for  sooner  or  later  it  will  surely 
fail  and  cause  annoyance. 

In  banding  a  tooth  where  there  is  much  crowding  it  may  be  necessary 
to  provide  space  in  advance.  Usually,  however,  by  exercising  a  little 
care  and  patience  the  banding  may  be  done  at  one  sitting. 


774  ORTHODONTIA 

Adjustment  of  Expansion  Arches. — In  adjusting  any  of  the  expansion 
arches,  tliey  are  iirst  l)ent  to  the  p^encral  form  of  the  dental  arch  with 
the  teeth  in  their  nuUarrani^enient.  But  as  the  movement  of  the 
teeth  progresses  it  is  occasionally  necessary  to  modify  this  form,  grad- 
ually approaching  the  ideal,  which  corresponds  with  the  line  of  occlusion. 
The  ex])ansion  arch,  therefore,  becomes  a  guide  and  pattern  for  the 
proj)er  alignment  of  the  teeth  as  well  as  the  means  of  effecting  their  move- 
ment by  reason  of  its  elasticity,  in  connection  with  the  wire  ligatures. 

Being  given  the  desired  size  and  form  and  being  properly  adjusted 
to  the  teeth,  its  further  adjustment  as  to  size  is  effected  by  tightening 
the  nuts  in  front  of  the  anchor  tubes.  The  tendency  of  beginners  is  to 
depend  principally  on  the  tightening  of  the  nuts  for  applying  j)ressure 
on  the  moving  teeth.  This,  however,  is  a  mistake,  as  the  principal 
force  should  be  derived  from  the  ligatures  and  the  elasticity  of  the  arch. 

Adjustment  of  Wire  Ligatures. — Uncjuestionably  the  greatest  modern 
improvement  in  connection  with  the  use  of  the  arch  is  the  substitution 
of  ligatures  of  brass*  for  fibrous  ligatures,  on  account  of  their  greater 
strength,  cleanliness,  and  freedom  from  stretching  or  slipping,  making 
their  force  direct  and  positive.  With  them  the  possibilities  in  the  use  of 
the  arch  are  greatly  extended,  shortening  the  time  of  treatment,  and 
making  easy  much  that  was  impracticable  or  even  impossible  before. 
One  of  their  valuable  qualities  is  that  they  may  be  retightened  by  twist- 
ing, without  renewal,  possessing  thereby,  in  addition  to  their  primary 
usefulness,  the  ideal  power  of  the  screw,  and  obviating  the  necessity 
for  the  oft  relinquishment  and  reapplication  of  pressure  on  the  moving 
tooth,  as  must  follow  the  use  of  other  ligatures — the  principal  source  of 
pain  and  inflammation  in  tooth  movement.  It  is  very  important, 
however,  that  only  wire  of  the  proper  metal,  quality,  and  size  be  used. 
It  is  also  important  that  in  temper  it  shall  be  very  soft,  so  made  during 
its  manufacture.     Wire  of  spring  temper  is  entirely  useless. 

WTien  applying  a  wire  ligature  a  piece  long  enough  to  be  firmly 
grasped  by  both  hands  should  be  used,  so  that  strong  steady  tension 
may  be  exerted  when  making  the  twist.  This  should  never  be  more 
than  three-fourths  of  a  turn  at  first,  as  greater  twisting  gives  no  addi- 
tional strength,  but  adds  only  useless  bulk.  The  surplus  ends  are  then 
clipped  off,  leaving  projections  one-eighth  of  an  inch  long.  These  ends 
are  then  curled  under  the  arch,  as  correctly  shown  in  Figs.  807  and  811, 
thus  providing  a  smooth  surface  for  the  lips.  Never  attempt  to  bend 
the  twisted  portion  of  the  ligature  out  of  the  way,  as  by  so  doing  the 
entire  strain  is  brought  on  one  strand,  and  the  ligature  usually  broken. 

In  retightening  the  ligature,  firmly  press  the  tooth  and  arch  between 
the  thumb  and  finger  while  giving  it  another  half-turn  with  suitable 
pliers.     Either  the  large  or  medium-sized  ligatures  should  be  used  for 

'  Angle,  Regulation  and  Retention  of  the  Teeth  and  Fractures  of  the  Maxillae, 
fourth  edition. 


ADJUSTMENT  AND  OPERATION  OF  APPLIANCES 


775 


the  movement  of  teeth,  yet  the  size  of  the  hgature,  the  degree  of  force 
exerted,  and  the  frequency  of  their  renewal  or  retiglitening  must  he  left 
wholly  to  the  judgment  of  the  operator.  The  usual  plan  is  to  tighten 
the  ligature  once  or  twice  a  week,  although  once  in  two  weeks  is 
sufficient. 

Although  the  uses  of  the  wire  ligature  in  orthodontia  are  limitless, 
there  are  three  principal  ways  of  applying  it  in  ligature  form:  first,  the 
simple  ligature,  as  in  .1,  A,  Fig.  807,  where  it  is  made  to  engage  a  single 
tooth  and  the  expansion  arch,  where  direct  labial  or  buccal  movement  is 
required;  second,  where  rotation  and  possibly  labial  movement  is  re- 
quired the  ligature  is  made  to  engage  the  expansion  arch  and  a  spur 
upon  a  band  cemented  to  the  tooth,  as  in  B,  Fig,  807;  third,  the  double 
loop  ligature,  as  in  C,  Fig.  807,  to  effect  the  same  movement.  The 
ligature  applied  in  this  manner  is  more  uncertain  in  its  results  than 
when  applied  as  last  shown,  and  should  rarely  be  used. 

Fig.  SU 


Combination  Adjusted. — Fig.  811  shows  the  expansion  arch  adjusted 
to  the  teeth  of  the  upper  dental  arch  in  the  very  complicated  case  shown 
in  Fig.  872.  This  case  required  the  movement  of  all  the  teeth  in  both 
arches  and  offered  the  severest  test  to  a  regulating  appliance,  at  the 
same  time  offering  us  the  best  of  opportunities  for  its  study,  with  a 
view  to  its  proper  adjustment  and  operation,  not  only  in  this  case,  but 
for  most  general  uses.  Its  more  extended  uses  in  special  cases  will  be 
noted  later  in  the  treatment  of  individual  cases.  In  this  case  the  upper 
dental  arch  requires  much  widening,  while  both  centrals  and  both 
laterals  are  to  be  carried  labially  and  rotated,  and  the  canines  are  to 
be  elevated  in  their  sockets. 

Plain  spurred  bands  and  ligatures  were  adjusted  to  all  the  incisors  for 
their  combined  labial  movement  and  rotation,  the  spurs  on  the  plain 
bands   having  been  so  placed   that  force  exerted   by  reason  of  the 


776 


ORTHODONTIA 


elasticity  of  the  arch  throucrh  the  wire  h^atures  bore  most  heavily  on  the 
angles  of  the  teeth  that  were  turned  linoiuilly,  and  as  they  were  rotated 
they  were  also  drawn  labially.  By  using  the  ribbed  expansion  arch 
and  notching  the  ril)  for  the  ujore  stable  attachment  of  the  ligatures,  the 
direction  of  force  for  moving  these  teeth  was  absolutely  controlled. 

The  first  molars,  attached  to  the  expansion  arch  through  the  clamp- 
bands,  were  moved  buccally  by  reason  of  the  lateral  s])ring  of  the  expan- 
sion arch.  The  first  premolars  were  moved  in  the  same  direction  through 
their  attachment  to  the  arch  by  plain  wire  ligatures,  and  the  second 
premolars  through  contact  with  the  screw  of  the  I)  bands.  Pressure 
on  the  canines  to  move  them  lingually  was  intensified  by  rubber  wedges 
stretched  between  teeth  and  arch  and  the  superfluous  ends  cut  off,  as 
shown  in  Fig.  808. 


Fig.  812 


By  carefully  studying  this  picture  it  will  be  seen  how  perfectly  force 
is  distributed  to  accomplish  the  various  necessary  tooth  movements,  and 
how,  as  in  all  fine  mechanisms,  each  part  assists  and  is  in  harmony  with 
each  other  part.  For  example,  note  how  perfecdy  the  force  is  recipro- 
cated from  one  moving  tooth  to  another;  from  one  lateral  half  of  the 
dental  arch  to  the  other,  and  how  this  is  intensified  by  the  pressure  on 
the  centre  of  the  expansion  arch  in  front,  the  tendency  being  when 
pressure  is  exerted  at  this  point,  as  in  all  arches,  to  spring  the  ends 
farther  apart.  As  the  central  incisors  were  rotated,  much  force  was 
exerted  upon  them  at  their  diagonally  opposite  corners;  in  reality  the 
arch  operating  on  each  as  two  levers  combined,  the  power  ends  acting 
in  different  directions.  No  tooth  can  resist  this  force.  At  the  same  time 
all  four  incisors  were  carried  forward  by  the  irresistible  force  of  what 
is  practically  two  jack-screws  combined. 

In  the  anterior  teeth,  one  lateral  incisor  reciprocated  its  force  with  the 
other,  one  central  with  the  other,  all  in  perfect  harmony.    Note,  also,  w  hat 


ADJUSTMENT  AND  OPERATION  OF  AI'I'UANCES  777 

complete  control  wo  liave  over  the  teetli  singly  and  collectively,  yet  at 
the  same  time  the  iuich()r;in;e  is  derived  from  practically  all  of  the  teeth 
in  the  arch. 

In  applying  force  to  the  moving  teeth  the  medium-sized  brass  wire 
ligatures  were  used,  being  renewed  or  retightened  once  or  twice  a 
week,  all  the  force  they  would  bear  being  applied  to  them.  The  nuts 
of  the  expansion  arches  were  tightened  about  one  revolution  per  week, 
always  after  the  ligatures  had  been  tightened.  The  expansion  arch 
was  occasionally  removed  and  slightly  modified  as  to  form,  and  the 
full  amount  of  lateral  spring  maintained. 

With  this  appliance  we  may  not  only  expand  the  arch  in  all  directions, 
as  required  in  this  case  and  here  shown,  but,  as  we  shall  see  in  the  sec- 
tion on  Treatment,  we  may  widen  or  narrow  either  or  both  of  the  dental 
arches  on  one  or  both  sides,  or  we  may  lengthen  or  shorten  one  or  both 
of  the  lateral  halves.  We  may  move  a  single  tooth  in  any  direction, 
or  we  may  lengthen  the  teeth,  and,  to  a  limited  extent,  effect  their 
shortening. 

In  adjusting  the  arch,  as  here  shown,  it  will  be  seen  that  it  is  placed 
high  up  toward  the  gum,  as  it  should  be  in  all  cases.  This  is  necessary 
in  order  to  keep  intense,  rigid  tension  upon  the  moving  teeth,  for  if  the 
arch  be  allowed  to  slip  down  (its  natural  tendency)  toward  the  points 
of  the  teeth,  it  will  lose  much  or  all  of  its  force,  and  become  a  wobbly, 
inefficient  incumbrance.  For  this  reason  the  spurs  upon  plain  bands 
for  engaging  the  ligatures  should  be  placed  as  high  up,  or  as  near  the 
gum,  as  possible,  and  also,  at  such  an  angle  as  will  prevent  the  ligatures 
from  slipping  off. 

A  common  failing  of  the  inexperienced  is  to  give  the  arch  so  much 
lateral  spring  as  to  cause  buccal  displacement  of  the  anchor  teeth  in 
cases  in  which  no  buccal  movement  of  these  teeth  is  necessary. 

In  using  the  plain  expansion  arch,  as  here  shown,  spurs  are  soldered 
at  points  best  calculated  to  prevent  the  ligatures  frorn  slipping  and  to 
control  the  desired  direction  of  force.  These  spurs  are  attached  with 
soft  solder,  as  previously  described  (page  764).  It  is  impossible  to  always 
foretell  the  exact  location  at  which  these  spurs  should  be  placed  so  that 
they  may  be  attached  before  the  arch  is  adjusted,  making  the  removal 
of  ligatures  and  arch  and  their  readjustment  after  the  spurs  have  been 
added  often  necessary.  Now,  this  has  a  serious  objection,  for  it  must 
be  remembered  that  the  relinquishment  and  reapplication  of  force  to 
moving  teeth  is  the  most  certain  and  speedy  method  of  exciting  inflam- 
mation, and  should  be  avoided  whenever  possible.  For  this  reason  the 
brass  wire  ligatures  should  be  retightened  without  renewal  as  long  as  is 
practicable. 

To  avoid  the  necessity  of  removing  the  plain  arch  for  the  attachment 
of  spurs,  the  ribbed  arch  was  invented,  and  it  is  of  decided  advantage, 
for  notches  may  be  made  in  the  rib  at  desired  points  quickly  and  easily 


778 


ORTIIODOXTIA 


with  the  arch  in  position  upon  tiie  teeth,  thus  avoiding  much  j)ain  and 
the  Hahihty  of  exciting  inflannnation. 

The  notches  are  best  made  with  a  delicate  knife-edge  file,  and  should 
be  made  deep  enough  and  at  the  proper  angle  to  efFectually  prevent 
the  ligatures  from  slipping.  ]\Iere  ^ -shaped  notclies  are  useless.  They 
should  be  given  decided  angles,  as  shown  in  the  enlarged  section,  Fig. 
SI 3.  The  ribbed  arch,  as  here  shown,  Fig.  SI 3,  also  gives  considerable 
additional  force  in  widening  the  dental  arch,  so  that  reinforcement  by 
means  of  the  lingual  wire  (Fig.  811)  is  now  rarely  necessary. 

Fig.  813 


Objections  have  been  offered  to  the  ribbed  arch  on  account  of  its 
supposed  greater  lial)ility  to  al)rade  the  mucous  meml)rane  of  the  lips, 
but  the  writer  has  always  found  that  the  arch  was  not  properly  adjusted 
when  this  occurred,  but  had  l)een  allowed  to  stand  out  from  the  teeth, 
sometimes  to  an  absurd  degree,  instead  of  conforming  compactly  to  the 
teeth,  as  shown  in  Fig.  769.    Again,  the  superfluous  ends  of  the  rib  should 


Fig.  814 


E.H 


be  removed  with  a  file  and  the  arch  neatly  burnished,  especially  if, 
through  necessity,  the  arch  is  given  much  prominence  on  account  of 
the  position  of  the  canine  teeth.  When  intelligently  studied  and  properly 
managed  the  great  value  of  the  ribbed  arch  will  become  better  and 
better  appreciated. 

Fig.  814  shows  the  adjustment  of  the  combination  to  the  lower  dental 
arch.     It  will  be  noted  that  the  principal  necessary  movement  of  the 


ADJUSTMENT  AND  OPERATION  OF  APPLIANCES  779 

canines  is  buccally,  so  the  notches  in  the  arch  have  been  })laced  well 
back  to  best  accomplish  this  movement.  Later  it  may  be  necessary  to 
place  bands  and  spnrs  on  the  rif^ht  canine  and  on  the  central  incisors  in 
order  to  better  control  their  movement  for  partial  rotation. 

By  the  addition  to  this  combination  of  sheath-hooks  and  rul^ber  liga- 
tures used  in  the  Baker  anchorage,  all  of  the  upper  teeth  may  be  moved 
distally  and  all  the  lower  teeth  mesially,  as  illustrated  in  Fig.  70G,  or 
these  movements  may  be  reversed,  as  shown  in  Fig.  812,  and  all  this  in 
connection  with  any  other  tooth  movements  that  may  be  required  in 
either  or  both  arches. 

The  modifications  of  form  and  directions  of  spring,  plus  the  modifi- 
cations in  ligature  attachments,  make  it  possible  to  derive  wonderful 
control  of  force  in  tooth  movement,  and  in  the  use  of  this  appliance  it 
is  possible  to  cultivate  a  very  high  degree  of  skill.  It  typifies  efficiency 
and  simplicity.  It  is  easily  applied,  and  is  so  stable  in  its  attachment  that 
there  need  be  no  slipping  or  loss  of  power.  It  is  cleanly,  and  occupies  a 
position  in  the  mouth  that  causes  the  least  inconvenience  to  the  patient. 
If  this  device  be  intelligently  managed,  it  need  interfere  but  little  with  the 
normal  functions  of  the  mouth.  On  the  contrary,  however,  if  improperly 
managed  it  becomes  a  constant  annoyance,  as  has  been  said,  and  one  of 
the  most  wobbly  and  useless  of  devices. 

In  its  proper  use  the  widest  range  for  reciprocal  anchorage  is  possible. 
We  may  also  gain  simple  and  a  considerable  degree  of  stationary  anchor- 
age by  reason  of  the  tubes  and  firm  attachment  of  the  anchor-bands  to 
the  teeth  used  as  anchorage,  and  also,  as  we  have  seen,  the  very  valuable 
intermaxillary  anchorage. 

The  necessary  direction  and  distribution  of  force  should  be  carefully 
studied  in  each  case,  as  well  as  the  effect  upon  the  anchor  teeth  and  all 
teeth  that  are  in  correct  position. 

Let  us  repeat  that  the  arch  should  always  be  made  to  lie  approxi- 
mately close  to  the  teeth,  so  as  to  interfere  as  little  as  possible  with  the 
functions  of  the  lips. 

It  should  be  remembered  that  as  its  force  in  tooth  movement  is  exerted 
usually  by  its  elasticity,  its  careful  bending  in  order  to  secure  the  proper 
degree  and  direction  of  force  is  of  much  importance.  To  make  the 
most  of  this  possibility,  and  at  the  same  time  avoid  interference  with 
desired  movements  or  with  teeth  already  in  correct  position  by  binding, 
is  the  most  difficult  problem  in  its  management,  and  yet  it  is  easily  solved 
if  intelligently  studied  in  each  case. 

As  a  result  of  years  of  experimenting,  it  is  believed  that,  as  here  shown, 
with  its  improvements  and  attachments  (Fig.  760),  it  is  very  nearly 
perfect. 

In  order  that  the  patient  may  become  gradually  accustomed  to  the 
appliances,  the  bands  should  be  worn  for  two  or  three  days,  then  the  arch 
added  without  ligatures  for  three  or  four  days  more,  and  finally,  all  care- 


780  ORTHODONTIA 

fullv  and  thorouojhly  adjusted  and  tlic  li(ijattir(>.s  applied  for  the  movement 
of  the  teeth.  They  should  be  very  light  of  tension  at  first,  the  object 
being,  of  course,  to  begin  so  gently  that  the  patient  may  become  accus- 
tomed to  the  wearing  of  the  device  with  no  })ain  and  w'ith  but  the  mini- 
nmm  amount  of  inconvenience,  all  of  which  is  easily  possible.  The 
tendency  of  all  appliances  upon  the  teeth  is  at  first  to  excite  more  or 
less  inflammation,  which  will  be  in  pro]>ortion  to  the  amount  of  force 
exerted;  therefore  we  cannot  too  strongly  recommend  that  the  adjustment 
of  the  appliances  should  always  be  gradual,  and  the  force  exerted  in  the 
beginning  most  gentle.  Later,  much  pressure  can  be  borne  with  litde 
inconvenience. 

Although  in  cases  met  with  for  treatment  the  malocclusion  always 
differs,  the  adjustment  of  the  expansion  arch  as  here  given  is  j)ractically 
always  the  same,  the  principal  ditrerence  being  in  the  form  given  the  arch 
by  bending  in  order  to  exert  force  in  the  desired  direction,  and  in  the 
direction  of  the  ligatures  and  their  attachments  to  the  teeth  to  be 
moved. 

Combinations  for  Intermaxillary  Anchorage. — Fig.  806  shows  a  very 
important  combination  of  the  expansion  arches  in  which  the  inter- 
maxillary anchorage  is  used  in  the  movement  distally  of  the  teeth  of 
the  upper  and  mesially  those  of  the  lower  arch  in  the  correction  of  the 
malocclusion  of  cases  belonging  to  Class  II. 

The  expansion  arches  are  adjusted  in  the  usual  way,  sheath-hooks 
having  been  attached  to  the  upper  at  points  opposite  the  lateral  incisors. 
Either  the  plain  or  ribbed  arches  may  be  used,  but  the  plain  arch  is 
preferable  in  this  combination  unless  other  movements  of  the  incisors 
and  canines  are  necessary,  as  already  described,  and  illustrated  in  Fig. 
811.  The  force  is  exerted  by  means  of  one  or  more  small  rubl)er  liga- 
tures on  each  side,  which  engage  the  sheath-hooks  on  the  upper  expan- 
sion arch  and  the  distal  ends  of  the  sheaths  of  the  anchor-bands  on  the 
lower  molars.  For  description  of  the  operation  of  this  combination  of 
appliances  in  treatment,  see  page  851. 

The  combination  of  appliances  for  the  treatment  of  cases  belonging 
to  the  subdivisions  of  this  class  is  identical  with  that  just  described, 
except  that  intermaxillary  force  is  limited  to  the  side  of  the  arches  in 
distal  occlusion.  Only  one  sheath-hook  should  be  used,  with  its  accom- 
panying rubber  ligatures. 

In  the  treatment  of  cases  belonging  to  Class  III  the  same  combina- 
tion of  appliances  is  used,  but  the  plan  of  operation  is  reversed,  as 
shown  in  the  diagram  (Fig.  812).  The  sheath-hooks  are  attached  to  the 
lower  expansion  arch,  well  forward,  and  rubber  ligatures  are  stretched 
between  them  and  the  distal  ends  of  the  sheaths  of  the  anchor-bands  on 
the  upper  molars. 

For  the  treatment  of  cases  belonging  to  the  subdivision  of  Class  III 
the  same  combination  of  appliances  is  used,  with  force  from  the  rubber 
ligatures  exerted  on  the  abnormal  side  only. 


ADJUSTMENT  AND  OPERATION  OF  AI'l'LIANCES  781 

It  will  he  seen  that  all  cases  of  all  classes  may  be  treated  with  this 
appliance,  and,  we  now  believe,  more  quickly,  more  easily,  far  better, 
and  with  far  less  inconvenience  to  the  patient  than  with  any  other  form 
of  appliance.  It  is  the  one  that  seems  to  be  most  natural  to  meet  the 
demands  of  occlusion,  for  with  it  we  can  have  control  of  the  entire 
dental  apparatus — something  impossible  in  the  use  of  the  innumerable 
appliances  that  have  been  devised  for  the  correction  of  symptoms  only, 
without  regard  for  the  laws  of  occlusion.  He  who  will  study  its  possi- 
bilities will  be  more  and  more  impressed  with  its  wonderful  efficiency 
and  great  simplicity. 

Expansion  Arch  Reinforced. — ^The  elasticity  of  the  plain  expansion 
arch  is  sufficient  to  exert  ample  force  for  widening  either  of  the  dental 
arches;  yet  in  very  rare  instances  where  the  patient  has  reached  maturity, 
the  force  may  not  be  sufficient  to  accomplish  the  desired  movements  as 
rapidly  as  may  be  wished.  To  meet  this  limitation  the  arch  may  be 
reinforced  by  a  piece  of  spring  wire,  which  should  be  adjusted  to  exert 

Fig.  815 


pressure  upon  the  lingual  surfaces  of  the  anchor-bands,  as  in  Figs.  811 
and  815,  and  attached  on  each  side  by  uniting  two  short  tubes,  R  and  D, 
at  right  angles,  the  longer  one  slipped  over  the  end  of  the  screw  of  the 
D  band,  and  the  ends  of  the  lever  bent  sharply  at  right  angles  and  made 
to  engage  the  short  tubes.  Any  desired  degree  of  force  may  be  easily 
gained  with  this  simple  method  of  reinforcement. 

A  simpler  way  of  securing  the  reinforcement  spring  is  to  insert  its 
finely  pointed  ends,  bent  sharply  outward  at  right  angles,  into  very 
delicate  perforations  made  in  the  anchor-bands  at  their  mesio-lingual 
angles,  as  in  Fig.  878,  the  ends  passing  through  the  band  and  extending 
between  enamel  and  band. 

In  Fig.  815  the  threaded  ends  of  the  arch  are  seen  to  project  through 
the  distal  ends  of  the  sheath.  This  is  never  permissible.  The  ends  of 
the  arch  should  be  clipped  off  even  with  the  ends  of  the  sheaths  and  the 
roughened  ends  made  smooth,  otherwise  painful  abr^siions  of  the  cheeks 
are  likely  to  follow. 


782 


ORTHODONTIA 


MISCELLANEOUS    COMBINATIONS 

Traction-screw. — Although  there  are  many  possible  combinations 
with  the  traction-screw,  in  reality  its  uses  should  he  limited  to  two  or 
possibly  three.  Formerly  its  most  important  u.se  was  that  of  retraction 
of  that  most  obstinate  tooth,  the  canine,  as  shown  in  Figs.  816  and 
817.  This  it  accomplishes  so  easily  and  so  perfectly,  when  properly 
adjusted  and  managed,  that  it  easily  takes  rank,  we  believe,  over  all 
other  appliances  for  this  purjjose;  but  since  the  advent  of  intermaxillary 
anchorage,  making  extraction  in  treatment  unnecessary,  its  use  is 
rarely  required. 

In  its  correct  adjustment  the  canine  and  the  anchor  tooth  are  carefully 
banded  after  the  manner  described  for  adjustment  of  the  plain  and 
anchor-bands.  The  traction-screw  is  then  held  in  position,  and  the 
short  and  long  sheaths  made  to  touch  the  bands  at  the  exact  points  they 
are  to  occupy  when  soldered.    With  a  suitable  instrument  the  anchor- 


E.KA 


Fig.  816 


Fig.  817 


No.  a 


band  is  scratched  parallel  with  the  long  sheath  to  indicate  its  align- 
ment. The  side  of  the  long  sheath  is  then  filed  to  permit  of  close  con- 
tact with  the  band  and  to  give  increased  surface  for  the  solder,  filing 
through  being  carefully  avoided.  The  band  is  then  replaced,  and  the 
exact  point  of  contact  of  the  edge  of  the  short  sheath  with  the  band 
on  the  canine  is  located  and  indicated  by  a  suitable  mark.  Lest  this  be 
obliterated  upon  soldering,  the  band  may  be  perforated  at  this  point 
with  a  small  drill.  Having  noted  as  accurately  as  possible  the  angle  at 
which  this  sheath  shall  stand  to  properly  line  with  the  right  angle  of 
the  shaft,  minute  notches  are  made  in  the  edge  of  the  band  mesially  and 
distally,  to  line  with  the  end  of  the  sheath  (Fig.  818).  The  bands  are 
now  removed  from  the  teeth  and  the  sheaths  from  the  screw,  and  a 
minute  piece  of  solder  partially  fused  upon  the  edge  of  the  short  sheath 
at  the  point  intended  for  attachment  to  the  band.  It  is  then  held  with 
pliers  in  the  left  hand,  the  band  being  held  by  its  untrimmed  ends  in 
the  right  hand,  the  end  of  the  sheath  lining  with  the  notches  A  and  B, 
Fig.  818,  and  the  solder  fused  by  contact  with  the  flame  at  the  proper 
point. 


MISCELLANEOUS  COMBINATIONS  783 

It  is  highly  essential  that  the  sheath  be  attached  at  the  right  point 
and  at  the  proper  angle,  or  the  angle  of  the  screw  will  not  fit. 

Be  it  remembered  that  the  sheath  attached  to  the  canine  band  nmst 
always  stand  at  right  angles  to  the  long  axis  of  the  tooth,  that  a  free 
hinge-like  movement  of  the  tooth  in  retraction  may  be  gained;  not 
parallel  with  the  long  axis,  as  some  will  persist  in  attaching  it,  with 
resultant  binding  and  prevention  of  free  movement. 

The  sur})lus  ends  of  the  band  are  now  trimmed  off  and  smoothed, 
and  the  band  deoxidized  and  cemented  in  position.  While  the  cement 
is  hardening  the  long  sheath  is  soldered,  according  to  alignment,  to  the 
No.  2  band.  It  is  then  cleansed  and  slipped  upon  the  screw  and  the 
nut  adjusted,  the  angle  is  hooked  into  the  sheath  upon  the  canine  band, 
and  the  clamp-band  slipped  over  the  crown  of  the  molar  and  gently 
tightened.     It  is  allowed  to  remain  a  day  or  two  before  cementing,  in 

Fig.  818 


order  that  this  operation,  so  important  to  thoroughly  perform,  may  be 
accomplished  without  interference  by  pressure  from  the  approximal 
teeth,  and  also  that  both  the  canine  and  the  anchor  tooth  may  slightly 
move  and  become  more  perfectly  adjusted  to  their  relations  with  the 
two  bands. 

The  proper  length  of  the  screw  having  been  determined,  it  is  cut 
off  behind  the  nut.  Heat  must  in  no  instance  come  in  contact  with 
any  portion  of  the  shaft  of  the  screw. 

Before  finally  cementing  the  molar  band  in  position  it  should  be 
removed,  and  it  and  the  crown  of  the  molar  thoroughly  cleansed  and 
dried.  The  crown  being  properly  protected  from  moisture,  cement  is 
mixed  to  the  correct  consistence  and  the  interior  of  the  band  nearly 
filled.  The  angle  of  the  traction-screw  is  then  inserted  into  the  short 
sheath,  and  the  anchor-band  and  cement  carried  down  over  the  crown 


784 


ORTHODONTIA 


of  the  molar  with  the  thumh  and  finder,  forcin<i;  the  cement  well  clown 
by  pressure  from  the  thumb.  The  hand  is  cjuiekly  worked  to  the  desired 
position,  and  the  nut  of  the  band  tightened  until  it  is  firmly  clamped. 
The  superfluous  cement  is  then  wiped  off,  and  the  patient  dismissed 
until  the  next  sitting  before  tightening  of  the  nut  of  the  traction-screw 
is  begun,  in  order  that  the  cement  shall  become  thoroughly  set  and 
the  most  rigid  possible  attachment  gained. 

If  the  operation  thus  far  has  been  carefully  performed,  the  nearest 
approach  to  stationary  anchorage  possible  to  obtain  in  the  mouth  will 
have  been  gained,  so  that  the  canine  may  be  moved  distally  without 
changing  the  relation  of  the  occlusal  planes  of  the  anchor  tooth  with 
those  of  the  opposite  jaw.  It  is  very  important,  however,  not  to  strain 
the  attachment  by  overtightening  the  nut  of  the  traction-screw  at  any 
time.  One-half  a  revolution  the  nut  each  day  or  just  enough  to  exert 
a  slightly  snug  feeling  upon  the  canine,  is  all  the  force  that  should  be 
exerted  at  anv  one  time. 


Fig.  819 


Fig.  820 


D-- 


E.H.A. 


It  is  very  important  that  the  angle  of  the  screw  be  passed  into  the 
sheath  its  full  length,  otherwise  it  will  be  broken  when  force  is  exerted. 

If  it  is  desired  to  rotate  the  canine  as  it  is  moved  distally,  it  may  be 
accomplished  by  using  a  staple  instead  of  a  sheath  for  engaging  the 
angle  of  the  traction-screw,  as  shown  in  Fig.  819.  In  this  instance  the 
angle  of  the  screw  is  parallel  with  the  long  axis  of  the  tooth,  instead 
of  at  right  angles  to  it,  as  when  the  tube  is  used.  In  this  manner  force 
is  exerted  on  one  side  of  the  band  only,  and  rotation  as  well  as  retrac- 
tion takes  place. 

The  shifting  of  the  canine  lingually  or  labially  in  its  distal  move- 
ment may  be  accomplished  by  bending  the  .screw  where  it  enters  the 
sheath.  As  the  nut  is  tightened  the  screw  is  gradually  straightened  as 
it  is  drawn  into  the  sheath,  thus  arranging  the  teeth  in  proper  align- 
ment. 


MISVELLANEOIS  COMBINATIONS  785 

Fig.  819  shows  the  use  of  a  traction-screw  in  effecting  rotation  of  a 
premoUir  tooth  in  comlnnation  with  the  clamp-hands  Nos.  1  and  2. 
The  angle  of  the  screw  engages  a  staple  made  of  the  G  wire  soldered 
to  the  mesio-lingual  angle  of  the  band  encircling  the  premolar.  By 
tijihteninsj  the  nut  at  .1,  traction  force  is  exerted  on  one  side  only,  while 
resistance  in  the  opposite  direction  is  offered  by  the  intervening  pre- 
molar. The  great  power  thus  exerted  makes  this  the  most  efficient 
method  known  of  rotating  a  premolar,  and  is  one  that  is  occasionally 
used  by  the  writer,  always  with  much  satisfaction,  but  only  used  when 
a  single  tooth  is  greatly  turned  upon  its  axis,  as  in  cases  belonging  to 
the  first  division  of  Class  II,  where,  after  all  the  other  teeth  have  been 
moved  into  their  normal  relations,  it  is  desirable  to  remove  the  expan- 
sion arch  and  eft'ect  retention,  when  rotation  of  this  tooth  may  be  fin- 
ished, as  here  described.  In  such  cases  the  expansion  arch  may  be 
used  at  the  same  time,  in  combination  with  this  appliance,  in  which 
case  the  clamp-band  D  would 'be  adjusted  to  the  second  molar.  Of 
course,  all  ordinary  rotation  of  premolars  would  be  effected  in  the  usual 
way,  or  by  means  of  plain  spurred  bands,  wire  ligatures,  etc.,  in  com- 
bination with  the  expansion  arch. 

In  Fig.  820  is  shown  another  use  of  the  traction-screw  in  effecting 
the  labial  movement  of  a  lateral,  and  at  the  same  time  providing  space 
for  its  movement.  A  strip  of  band  material  F  is  looped  around  the 
lateral,  the  ends  resting  on  the  labial  surfaces  of  the  adjoining  teeth. 
To  one  end  is  soldered  vertically  one  of  the  short  tubes  D,  while  on  the 
other  end  is  a  similar  tube  attached  horizontally.  Into  these  tubes  the 
traction-screw  is  placed,  being  bent  to  conform  to  the  proper  curve  of 
the  arch,  and  as  the  nut  is  tightened  the  ends  of  the  ribbon  of  band 
material  are  pushed  farther  apart,  thus  providing  space  for  the  lateral 
as  it  is  carried  into  correct  position.  This  combination  is  now  practically 
obsolete  for  the  movement  of  the  lateral,  as  here  described,  or  for  any 
of  the  anterior  teeth,  the  same  movements  being  far  more  easily  accom- 
plished by  means  of  the  expansion  arch.  Yet  it  is  valuable  on  rare 
occasions  for  moving  buccally  a  premolar  that  is  in  marked  lingual 
occlusion,  as  in  Fig.  828,  as  it  effectually  provides  space  for  the  tooth 
while  moving  it  buccally.  "\Mien  so  used  the  screw  is  left  straight,  lying 
close  against  the  buccal  surfaces  of  the  teeth. 

Fig.  821  shows  a  combination  of  traction-screw  and  expansion  arch 
for  shortening  oae  of  the  lateral  halves  of  the  dental  arch,  and  at  the 
same  time  correcting  malpositions  of  the  incisors. 

The  traction-screw  should  be  first  adjusted,  as  already  described,  and 
in  addition  it  should  be  piovided  with  one  of  the  tubes  D  soldered  to 
the  side  of  the  sheath  5^,  near  its  mesial  end.  This  is  for  the  reception 
and  support  of  one  end  of  the  expansion  arch  in  place  of  the  usual  D 
or  X  band.  The  nut  of  the  expansion  arch  is  to  bear  against  this  tube, 
and  when  so  used  the  nut  should  be  reversed,  the  extension  flange  turned 
50 


786 


OUT  IK)  DOM' I A 


mesially.  The  other  end  of  the  expansion  arch  is  supported  in  the  usual 
way,  as  in  Fig.  808.  As  the  canine  is  retracted  into  the  space  made 
vacant  by  the  k)ss  of  the  first  premolar,  the  malposed  incisors  are  rotated 
by  means  of  the  ligatures,  bands,  and  spurs,  as  is  well  shown  in  the 


Fig.  821 


engraving,  and  also  in  Fig.  811.  This  very  efficient  combination  was 
formerly  a  great  favorite  with  the  writer,  but  it  is  now  rarely  employed, 
as  intermaxillary  anchorage  has  made  the  establishment  of  normal 
occlusion  in  such  cases  easily  possible  and  the  sacrifice  of  the  premolar 
unnecessary. 


Fig.  822 


Fig.  823 


No.  2 


E.H.A. 


Jackscrew. — Since  the  Dwindle  jackscrew  was  introduced  in  1848 
for  orthodontic  purposes,  it  has  been  much  employed  by  dentists. 
The  writer's  jackscrew  was  formerly  a  very  important  part  in  many  of 
the  combinations  of  his  appliances,  and  notwithstanding  that  he  believes 
he  is  the  author  of  by  far  the  most  perfect  form  of  jackscrew  yet  given 
to  the  profession,  and  one  that  is  widely  used  and  often  imitated,  he 
believes  that  in  the  requirements  of  modern  orthodontia  it  is  one  of  the 


MISCELLANEOUS  COMBINATIONS  787 

poorest  of  aj)pli;uK'e.s  {iiid  tluit  its  use  should  he  practieally  discontinued, 
it  having  been  superseded  by  the  expansion  arch,  for  practically  all  of  the 
movements  possible  to  accomplish  with  the  jackscrew  are  better  and 
more  easily  performed  with  the  expansion  arch.  With  the  latter  we 
may  have  complete  control  of  the  force  exerted  on  both  anchor  and 
moving  teeth,  individually  and  collectively,  at  the  same  time  guarding 
the  positions  of  those  teeth  already  in  the  line  of  occlusion,  while  with 
the  jackscrew  our  control  over  the  force  is  necessarily  greatly  limited. 
Yet  in  favorable  cases,  which  are  rare,  it  will  doul)tless  always  be  a 
desirable  method  of  exerting  force,  owing  to  its  great  simplicity  and 
power.  Fig.  822  shows  one  of  the  writer's  favorite  methods  of  using 
the  jackscrew. 

An  anchor  band  provided  with  a  spur  of  wire,  G,  engages  one  end 
of  the  jackscrew.  The  flattened  end  is  notched  and  engages  a  staple 
soldered  to  the  lingual  surface  of  a  band  on  the  tooth  to  be  moved. 
The  jackscrew  is  powerfully  reinforced  by  a  section  of  the  wire  G,  as 
illustrated.  This  wire  engages  one  of  the  tubes,  R,  soldered  at  right 
angles  to  the  sheath  near  its  base,  its  ends  being  bent  in  the  form 
of  hooks  which  engage  wire  ligatures  encircling  the  canine  and  central 
incisor. 

Lever. — The  spring  lever,  L,  also  formerly  played  an  important  part 
in  the  combinations  of  the  writer's  appliances  for  accomplishing  rota- 
tion of  the  teeth,  but  with  it,  as  with  tlie  jackscrew,  it  is  difficult  to 
control  the  distribution  of  force,  so  it,  also,  has  been  largely  superseded 
by  the  expansion  arch. 

In  some  instances,  however,  it  is  valuable;  for  example,  after  teeth 
have  been  rotated  and  have,  through  accident,  partially  relapsed, 
they  may  be  easily  readjusted,  as  it  requires  but  little  force,  by  means 
of  a  band  provided  with  a  tube,  R,  for  the  insertion  of  the  power  end 
of  the  lever,  the  long  end  being  sprung  around  and  attached  to  a  favor- 
ably located  anchor  tooth  which  may  be  reinforced,  as  shown  in  Fig. 
823.  Or  the  attachment  to  the  anchor  teeth  may  be  effected  by  wire 
ligatures. 

Double  rotation,  as  shown  in  Figs.  824,  825,  and  826,  may  also  be 
accomplished  by  means  of  the  lever  made  to  exert  force  by  engaging 
tubes,  or  spurs  and  ligatures,  as  shown  in  the  engravings;  but  we  insist 
that  they  should  rarely  be  employed  in  the  first  adjustment  of  the  teeth, 
as  teeth  in  these  positions  are  usually  only  the  prominent  symptoms 
of  more  or  less  general  malocclusion  which  demands  attention  first. 
For  this  reason  the  expansion  arch,  acting  upon  all  of  the  teeth,  thus 
providing  space  for  the  moving  teeth,  as  well  as  effecting  their  movement, 
is  best.  But,  as  we  have  said,  for  teeth  that  have  partially  relapsed  these 
are  simple  and  efficient  ways  of  readjusting  them,  as  well  as  for  their 
temporary  retention. 

A  novel  way  of  effecting  double  rotation  and  retention  in  simple 


788 


ORTHODONTIA 


cases  is  shown  in  Fio;.  S27.  Spurs  or  tubes  soldered  to  the  mesiolabial 
angles  of  bands  on  the  central  incisors  are  engaged  by  a  wire  ligature, 
which,  being  tightened,  draws  the  teeth  mesially,  while  force  in  the 
opposite  direction  is  exerted  by  a  rubber  wedge  stretched  between 
these  teeth  and  resting  in  contact  with  their  mesio-lingual  angles. 


Fig.  825 


Fifi.  826 


Another  simple  but  often  useful  little  appliance  is  shown  in  Fig. 
828,  where  a  tooth  is  being  moved  into  the  line  of  occlusion  by  means  of 
either  a  rubber  or  wire  ligature  made  to  engage  the  tooth  to  be  moved 
and  a  section  of  wire  G,  which  is  held  in  position  l)y  attachment,  either 
by  solder  or  a  tube,  to  a  clamp  band  encircling  an  adjoining  tooth. 


Fig.  827 


Fig.  828 


Fig.  829  shows  the  simplest  of  all  regulating  devices,  yet  one  that  is 
very  efficient  and  valuable,  especially  in  increasing  the  distance  between 
deciduous  canines,  as  here  shown,  to  release  lateral  pressure  upon 
erupting  permanent  incisors. 


Fig.  829 


^-»n. 


It  consists  of  a  section  of  wire  (r,  the  ends  sharpened  and  made  to 
rest  in  delicate  pits  in  the  enamel  of  lower  deciduous  canines.  Irresistible 
force  is  brought  to  bear  on  these  teeth  by  an  occasional  pinch  of  this 


RETENTION 


789 


wire  with  the  ro<^iilatnig  phers,  the  eifect  being  to  lengthen  the  wire. 
The  lower  teeth  so  moved  will  act  through  their  inclined  planes  upon 
the  upper  canines,  and  in  like  manner  etVect  their  buccal  movement, 
thereby  releasing  pressure  from  the  upper  permanent  incisors.  This 
would  be  the  ideal  treatment  for  such  cases  as  that  shown  in  Fig.  712. 


Fir..  S30 


Fig.  831 


As  here  described,  it  is  useful,  of  course,  only  on  young  patients,  with 
the  wire  pinched  only  at  long  intervals,  say  a  month  intervening.  The 
same  principle,  however,  is  often  made  use  of  by  the  WTiter  in  older 
patients.  In  these  cases  a  thoroughly  annealed  section  of  one  of  the 
expansion  arches  is  used,  its  end  secured  by  solder  to  bands  cemented 
upon  the  canine  teeth,  as  shown  in  Figs.  830  and  831. 


RETENTION 


After  malposed  teeth  have  been  moved  into  the  desired  positions,  it 
is  of  the  greatest  importance  that  they  be  mechanically  supported  until 
all  tendency  to  return  to  their  former  malpositions  has  subsided;  but  it 
cannot  be  too  strongly  insisted  upon  that  unless  such  occlusion  has  been 
established  as  will  enable  the  inclined  planes  of  the  cusps  to  ultimately 
act  in  harmony  for  mutual  support,  permanency  of  the  teeth  in  their 
new  positions  after  the  retaining  devices  have  been  removed  cannot  be 
hoped  for.  It  should  be  borne  in  mind  that  all  retaining  devices  are 
only  temporary  assistants  to  the  permanent  establishment  of  the  normal 
functions  of  the  occlusal  planes  of  the  teeth,  and  of  harmony  in  the  forces 
which  act  upon  the  teeth. 

Time  Required  for  Retention. — The  time  required  for  mechanical 
retention  varies,  according  to  the  age  of  the  patient,  occlusion,  tooth 
movements  accomplished,  length  of  cusps,  health  of  tissues,  etc.,  from  a 
few  days  to  a  year  or  two  years,  or  even  longer,  while  perhaps  in  rare 
instances  retention  may  be  required  for  an  indefinite  period. 

The  support  of  teeth  that  have  been  directed  into  correct  positions 
during  the  period  of  eruption  is  usually  required  for  a  few  months  only. 


790  ORTHODONTIA 

while  a  much  longer  period  (at  least  a  year)  would  he  rec|uired  for  the 
same  teeth  it'  moved  after  the  full  development  of  their  alveoli. 

Again,  owing  to  the  great  disturbance  of  the  fibers  of  the  peridental 
membrane  of  a  tooth  which  has  l)een  rotated,  its  retention  rec|uires  a 
far  longer  time  than  if  the  movements  labially  or  lingually  had  been 
accomplished. 

A  rule  of  general  application  may  be  made,  that  three  times  the 
length  of  time  will  be  required  for  retention  of  teeth  of  patients  aged 
twenty-one  years  as  for  those  of  patients  aged  twelve,  the  same  tooth 
movements  having  been  performed. 

There  is  usually  a  temptation  to  remove  the  appliances  before  the 
teeth  have  become  thoroughly  established,  and  many  are  the  failures 
from  this  cause  of  otherwise  well-conducted  cases.  As  so  much  depends 
upon  this  part  of  the  operation,  it  is  far  better  that  the  appliances  be 
worn  even  longer  than  necessary,  than  that  they  be  too  early  removed. 

Principles  of  Retention. — As  the  tendency  of  teeth  that  have  been 
moved  into  occlusion  is  to  return  to  their  former  malpositions,  the  main 
principle  to  be  considered  by  the  designer  of  a  retaining  device  is  the 
antagonizing  of  the  teeth  in  the  directions  of  their  tendencies  only. 
Very  slight  antagonism  is  recjuired,  but  its  exercise  must  be  constant. 
If  the  student  will  keep  this  fact  in  view  he  will  realize  that  only  delicate 
devices  are  necessary,  and  will  be  impressed  with  the  utter  uselessness 
of  much  of  the  bulk  and  material  composing  so  many  of  the  retaining 
devices  shown  in  our  literature. 

With  this  in  view,  each  corrected  case  should  l)e  carefully  studied 
in  connection  with  the  original  models,  noting  the  various  directions  in 
which  the  teeth  are  inclined  to  move. 

To  secure  retention  we  have  at  our  disposal  support  or  anchorage 
from  the  following  sources:  first,  reciprocal,  or  the  pitting  of  one  tooth 
against  another,  their  tendencies  being  to  move  in  opposite  or  different 
directions;  second,  teeth  already  firm  in  the  arch;  and  third,  and  ulti- 
mately most  important,  the  occlusion  of  the  teeth. 

As  the  retaining  device  is  to  be  worn  for  a  considerable  time,  some 
prefer  its  construction  from  gold  instead  of  nickel  silver,  on  account  of 
the  tendency  of  the  latter  to  discolor  in  some  mouths;  but  it  is  a  fact, 
which  anyone  may  verify  by  experiment,  that  bands  of  the  same  deli- 
cacy will  give  far  less  trouble  by  loosening  if  made  of  nickel  silver  than 
if  made  of  gold  or  silver,  or  of  any  other  of  the  alloys,  and  hence  are 
preferable,  at  least  during  the  experimental  period  of  retention. 

The  appliances  necessary  for  retaining  the  teeth  need  never  be  bulky 
nor  complicated,  nor  comprise  a  large  number  of  pieces.  We  must 
remember  that  the  patient  is  probably  already  wearied  with  the  incon- 
venience of  the  regulating  appliances,  so  it  should  be  the  aim  to  make 
the  retaining  devices  as  delicate,  compact,  and  inconspicuous  as  possible, 
always,   however,   consistent  with   the   main   object — perfect  support. 


RETENTION  791 

The  more  securely  the  teeth  are  held,  the  more  rapidly  will  they  become 
firm  in  tlu'ir  new  positions.  For  this  reason,  and  that  they  may  be  as 
little  as  possible  under  the  control  of  the  patient,  the  a})])liances  should 
be  made  stationary  by  the  attachment  of  accurately  fitted  and  cemented 
bands  whenever  practicable.  They  should  also  be  readily  cleansible 
by  the  patient  with  the  brush,  that  they  may  in  no  way  injure  the  teeth, 
no  matter  ho.v  loui;  worn.  It  is  remarkable  how  compact,  simple, 
efficient,  and  cleanly  the  retaining  devices  may  be  made,  even  for  the 
most  complicated  conditions. 

The  problems  to  be  met  in  retention  are  limitless  in  their  variation, 
and  often  difficult,  and  the  possibilities  for  the  development  of  skill 
are  also  limitless.  We  will  here  suggest  only  such  devices  as  embody 
principles  which  admit  of  great  variation  and  which  have  been  most 
satisfactory  in  the  writer's  hands. 

Retention  of  Teeth  in  Cases  Belonging  to  Class  I. — As  the  movement 
of  teeth  in  cases  belonging  to  Class  I  has  been  conducted  independent 
of  the  mesial  or  distal  positions  of  the  teeth  of  the  opposing  arch,  a  con- 
dition met  with  in  cases  belonging  to  Classes  II  and  III,  we  have  here  but 
to  consider  methods  of  resisting  the  movements  of  individual  teeth  in 
each  arch,  independent  of  the  teeth  in  the  other  arch,  and  usually  teeth 
anterior  to  the  molars  only. 

Temporary  Retaining  Devices. — Before  adjusting  the  retaining  device, 
it  is  often  best  to  allow  the  regulating  appliances  to  remain  passively 
in  position  upon  the  teeth  for  two  or  three  weeks,  in  order  that  all  ten- 
derness of  the  teeth  may  subside.  Yet  upon  the  removal  of  the  regulating 
appliances  there  is  usually  found  to  be  more  or  less  soreness,  as  well  as 
mobility,  in  the  teeth.  It  is,  therefore,  difficult  or  impossilile  to  form  and 
fit  bands  with  any  considerable  degree  of  accuracy  without  occasioning 
pain,  and  pain  may  and  should  be  avoided.  After  removing  the 
expansion  arch  and  thoroughly  cleansing  the  teeth,  it  is  best  to  adjust 
a  temporary  device,  often  with  the  same  form  as  if  it  were  to  be  per- 
manent, with  looser  fit  of  bands,  which  mav  be  sfentlv  worked  into 
position  with  the  fingers  alone.  If  a  good  quality  of  cement  be  used 
the  device  will  be  firmly  held  in  position  for  a  few  weeks,  until  all  sore- 
ness shall  have  subsided,  when  a  device,  with  bands  and  all  other  parts 
of  the  most  perfect  fit  and  finish,  may  be  substituted.  This  may  be  of 
precious  metal  if  desired. 

Another  satisfactory  plan  for  temporary  retention  is  to  weave  strands 
of  the  wire  ligatures  about  the  teeth,  engaging  the  spurs  upon  the  bands 
which  have  been  used  in  efiecting  the  various  tooth  movements,  and 
in  this  way  antagonizing  the  teeth  in  the  direction  of  their  tendencies. 

This  is  an  excellent  method  of  temporary  retention,  and  one  that  may 
often  be  taken  advantage  of,  as  was  done  in  the  case  shown  in  Figs. 
832,  833,  and  834.  A  wire  ligature  was  made  to  engage  the  spurs  on  the 
central  incisors,  both  ends  brought  forward  and  tightlv  twisted  at  the 


792 


ORTHODONTIA 


mesio-labial  anpjles  of  the  centrals.  ""I'hen  another  Hfjature  was  made 
to  enga<j;e  the  spur  on  the  disto-Hnirual  angle  of  the  left  lateral  incisor, 
the  ends  brought  forward  across  its  labial  surface,  one  end  being  passed 
l)etween  the  central  and  lateral  and  made  to  engage  the  sj)ur  nj)()ii  the 
left  central,  brought  back  between  these  teeth,  and  firmly  twisted  with 
the  other  end  of  the  strand  of  ligature  at  a  point  on  the  labial  surface  of 
the  lateral  incisor,  as  indicated.  In  ])recisely  the  same  manner  a  third 
ligature  was  made  to  engage  the  spurs  upon  the  right  lateral  and  central, 
all  as  shown  in  Fig.  833.  V>\  studying  the  original  positions  of  the  teeth 
in  Fig.  S32,  it  will  be  seen  how  direct  and  jxisitive  is  the  reci])rocal  force 
exerted  by  these  ligatures  in  resisting  the  movement  of  the  teeth  in  the 
direction  of  their  tendencies. 


Fig.  833 


Fig.  834 


After  a  few  weeks  of  temporary  retention  the  teeth  were  permanently 
retained,  as  shown  in  Fig.  834,  by  other  l)ands  placed  upon  the  laterals 
and  connected  by  a  section  of  wire  in  the  usual  way,  as  described  else- 
where. 

Permanent  Retaining  Devices. — The  simple  band  and  the  short  pro- 
jecting wire,  which  for  convenience  we  call  a  spur,  form  the  basis  of  a 
principle  which  is  applicable  to  nearly  all  the  recjuirements  of  per- 
manent retention  in  all  the  various  classes.  It  is  surprising  to  find  in 
what  number  of  combinations  the  band  and 
spur  may  be  employed.  If  a  single  tooth  has 
been  rotated,  it  may  be  prevented  from  return- 
ing to  its  former  position  (or  antagonized  in 
the  direction  of  its  tendency)  by  a  band  with 
two  spurs,  as  in  Fig.  835.  These  may  be 
soldered  directly  to  the  band.  Unnecessarily 
long  spurs  should  never  be  used,  as  they  are 
cumbersome  and  unsightly.  Fven  shorter  spurs  than  those  shown  in 
the  engraving  may  be  employed. 

Much  care  should  be  exercised  in  j)lacing  the  points  of  the  spurs 
which  bear  against  the  adjoining  teeth  so  that  they  wnll  not  cause  dis- 
placement of  the  tooth  retained.  If  placed  as  showm  in  the  engraving, 
the  elevation  of  the  lateral  in  its  socket  would  be  inevitable,  on  account 
of  the  inclined  planes  of  the  adjoining  teeth  down  which  the  spur  will 
be  made  to  slide  by  the  tooth  in  its  tendency  to  return  to  its  original 
position.  (This  point  may  be  taken  advantage  of,  however,  in  some 
cases  in  which  it  is  desirable  to  force  the  eruption  of  a  tooth  slightly;  for 


RETENTION 


793 


example,  a  canine.)  Tlie  j)()int  of  the  s{)ur  in  the  case  shown  should 
bear  upon  the  jringival  ridge  of  the  central,  while  the  point  of  bearing 
upon  the  canine  should  be  above  the  swell  of  the  crown.  The  fine 
adjustment  of  the  spurs  should  be  left  until  the  cement  has  hardened 
after  setting  the  band,  when  they  may  be  bent  until  their  ends  touch  at 
the  exact  ])oints  recjuired.  In  some  instances  in  which  the  period  of  re- 
tention is  to  be  protracted,  or  where  bands  would  be  unpleasantly 
conspicuous,  spurs  may  be  set  in  fillings,  as  in  Fig.  836.  In  the  case  of 
deciduous  teeth  soon  to  be  lost,  spurs  may  be  cemented  in  cavities 
drilled  in  the  enamel  for  the  purpose,  in  preference  to  the  setting  of 
bands. 

A  method  often  desirable  when  the  space  of  a  lost  tooth  is  to  be  pre- 
served is  to  insert  between  two  bands  on  the  approximating  teeth  a  short 
section  of  wire,  G,  its  ends  being  engaged  in  tubes  R  soldered  to  the 
bands,  as  in  Fief.  837.  This  wire  mav  be  lengthened,  if  it  is  desired  to 
increase  the  space,  by  pinching  it  with  the  regulating  pliers. 


Fig.  836 


Fig.  837 


'--- F 


E.H.A. 


Fig.  838 


Another  excellent  modification  of  this  plan  is  shown  in  Fig.  838,  in 
which  one  band  is  dispensed  with,  one  end  of  the  section  wire  G  l:)eing 
bent  in  the  form  of  a  goose-neck  to  engage  the  mesial  surface  and  sulcus 
of  the  first  premolar,  the  other  end  being  soldered  directly  to  a  plain 
band  on  the  lateral  incisor.  If  two  approximating  teeth  have  been 
rotated  in  opposite  directions,  the  firmest 
support  is  given  them  by  encircling  each 
tooth  with  a  band,  across  the  labial  surface 
of  which  a  section  of  wire  is  soldered — prac- 
tically two  bands  and  spurs  united.  The 
spring  of  the  spur  makes  possible  a  greater 
precision  in  the  adjustment  of  the  bands, 
with  less  lial:)ility  of  subsecjuent  loosening, 
than  when  the  bands  are  united  directly 
by  solder. 

The  tendency  to  rotation  of  the  right 
central  and  lateral  incisors,  plus  the  lingual 
tendency  of  the  left  central  and  the  mesial 
tendency  of  all,  is  effectually  resisted  by  two 

bands  connected  by  a  spur,  with  an  additional  spur  made  to  bear  upon 
the  mesio-labial  angle  of  the  right  lateral,  as  in  Fig.  839.  The  engraving 
shows  the  ends  of  the  wire  G,  secured  by  engaging  tubes  soldered  to  the 


E.H.A. 


794 


ORTIlODOSriA 


lingual  surfaces  of  the  bands.  Direct  attachment  of  the  ends  of  the 
wire  to  the  i)ands  by  solder  may,  of  course,  also  be  used,  and  is  prefer- 
able. By  studying  the  tendency  of  the  teeth,  it  will  be  seen  how  effect- 
\-  {\\v\  are  resisted  by  this  device. 


ua 


Fui.   839 


Fir,.   S40 


Fia.  841 


E  HA. 


Fig.  840  shows  the  union  of  two  bands  by  a  section  of  wire  G,  em- 
ployed to  antagonize  the  lingual  tendency  of  two  lateral  incisors  which 
haye  been  moyed  labially  into  the  line  of  occlusion,  while  another  cora- 


Fir,.   S42 


bination  of  bands  and  spurs  (Fig.  841)  attached  to  the  centrals  would 
accomplish  the  same  result.  The  former  device  is  more  eflScient,  but 
less  esthetic  than  the  latter. 


F'iG.  843 


Fig.  842  shows  a  coml)ination  of  bands  and  spurs  of  great  simplicity 
used  to  resist  the  tendency  of  the  incisors  to  return  to  their  original 
positions,  which  are  shown  in  Fig.  843. 

Neatly  fitting  bands  upon  the  central  incisors  are  connected  on  their 


RETENTION 


795 


lingual  surfaces  l)y  a  section  of  the  wire  G,  the  ends  of  which  project  and 
bear  against  the  disto-lingual  surfaces  of  the  laterals,  while  two  spurs 
are  soldered  to  the  disto-labial  angles  of  the  bands  on  the  central  incisors 
and  bear  against  the  mesio-labial  angles  of  the  laterals.  This  is  probably 
the  simplest  possible  device  for  resisting  these  movements.     It  is  impor- 


FiG.  844 


Fig.  845 


tant  that  it  be  adjusted  with  accuracy,  and  also  that  the  ends  of  the  wire 
be  carefully  placed,  for  reasons  given  in  connection  with  the  description 
of  Fig.  835.  In  some  instances  it  may  be  an  advantage  to  provide  a 
suitable  resting  place  for  the  lingual  spurs  by  slightly  grooving  the 
marginal  ridge  of  the  laterals. 

Dr.  Jane  Bunker  has  ingeniously  modified  this  device,  as  shown  in  Figs. 
844  and  845,  in  which  a  section  of  wire  is  soldered  across  the  labial  sur- 


FiG.  846 


Fig.  849 


Fig.  S47 


Fig.  850 


Fig.  S48 


faces  of  the  two  bands  on  the  centrals,  after  which  all  of  that  portion 
of  the  labial  surface  of  the  bands  above  and  below  the  spur  is  carefully 
cut  away,  so  that  the  wire  only  is  in  evidence. 

Two  lingual  spurs  engage  the  laterals. 

This  plan  of  removal  of  a  portion  of  the  band  may  be  variously 


796 


ORTHODONTIA 


a})plied,  and  where  efficiency  is  in  a  deforce  sacrificed  for  estfietics,  the 
device  will  he  found  sufficiently  firm  as  to  make  its  use  often  desirahle. 
It  should  1)6  remembered  that  its  weakest  point  is  where  the  hand 
emerges  between  the  teeth  to  join  the  wire.  It  should  be  properly 
strengthened  at  this  point  with  solder. 

Another  very  useful  plan  for  accomplishing  the  same  result  is  to 
solder  a  section  of  wire  G,  directly  to  the  labial  surface  of  a  band  on 
each  lateral,  the  ends  l)eing  made  to  rest  against  the  labial  surfaces  of 
canines   and   centrals. 


Fig.  S4(j  shows  the  union  of  two  bands  by  a  section  of  wire  G,  which 
would  not  only  accomplish  the  same  result,  but  would  also  resist  lateral 
pressure  or  rotation  of  one  or  both  of  the  canines  if  required,  while  an 
additional  spur,  as  in  Fig.  848.  would  antagonize  the  tendency  of  the 
central  shown  in  Fig.  847. 

By  the  addition  of  two  spurs  to  this  combination,  as  in  Fig.  850, 
the  lingual  and  buccal  tendencies  of  the  first  premolars  are  also  resisted 
in  the  more  complicated  case  shown  in  Fig.  849. 

Another  very  simple  but  very  efficient  plan  of  retention  is  shown 
in  Fig.  851.  Bands  are  placed  on  the  lateral  incisors,  each  pro- 
vided with  a  short  spur  which  engages  the  disto-lingual  angle  of  the 
centrals,  and   two   long  spurs,  soldered   at   the  disto-labial   angles  of 


RETENTION 


797 


the  lateral  l)ands,  l)ear  heavily  uj)<)ii  tiie  cainnes  as  they  pass  di.stally 
to  be  engatjjed  by  wire  ligatures  encircling  the  premolars.  Thus,  the 
proper  width  of  the  arch,  as  well  as  tiie  positions  of  the  incisors  and 
canines,  are  maintained.  This  is  a  favorite  device  with  the  writer,  and 
is  susceptible  of  many  variations. 

It  will  be  seen  that  any  or  all  of  the  incisors  and  canines  may  be 
firmly  supported  by  combinations  of  the  band  and  spur,  and  that  the 
premolars  and  molars  may  be  included  by  extending  the  principle,  but 


Fig.  S52 


its  greatest  usefulness  is  limited  to  the  incisors  and  canines,  or  at  most 
extended  to  include  the  first  premolars.  If,  however,  a  single  premolar 
shall  have  been  rotated,  or  if  a  single  molar  or  premolar  shall  have  been 
moved  lingually  or  bucally,  the  band  and  double  spur  made  to  bear 
against  the  adjoining  teeth,  the  same  as  already  described  for  retention 
of  an  incisor,  will  be  most  efficient. 

In  the  use  of  all  bands  in  retention  we  would  caution  that  they  be 
inspected  at  least  once  in  two  months,  for  if  they  should  become  loosened 
they  would  act  as  receptacles  for  food  particles,  the  fermentation  of 
which  might  in  time  injure  the  enamel. 

A  very  simple  and  efficient  retaining  device  for  upper  molars  that 
have  been  moved  from  lingual  occlusion,  and  for  lower  molars  that  have 
been  moved  from  buccal  occlusion,  as  in  Figs.  872  and  877,  is  a  band 
and  spur  placed  upon  the  upper  molar,  the  spur  or  finger  being  made  to 


Fig.  853 


E.H.A. 


bear  against  the  incline  of  the  buccal  surface  of  the  lower  molar,  or  the 
mesial  or  distal  angle  of  a  lower  molar  or  premolar,  shown  in  Fig.  852. 
Not  only  is  this  device  efficient  as  a  retainer,  but  it  is  also  valuable  as 
a  regulating  device,  for  by  occasionally  bending  the  spur  to  increase  its 
efficiency,  the  buccal  movement  of  the  upper  molar  and  the  lingual 
movement  of  the  lower  may  be  accomplished  to  any  desired  distance, 
or  they  may  to  some  extent  be  shifted  mesially  and  distally  by  so  placing 
the  spurs  as  to  exert  a  mesial  or  distal  influence. 

The  spur  may  also  with  advantage  be  made  in  the  form  of  a  staple 


798 


ORTHODONTIA 


in  some  instances,  as  in  B,  Fig.  .S53,  as  its  doul)le  attachment  to  the 
band  insures  greater  strength. 

The  union  of  hand  and  sj)ur  should  be  reinforced  with  plenty  of  solder 
and  only  the  best  (juality  of  band  and  cement  used. 

When  a  number  of  the  molars  have  been  moved  buccally,  a  metal  or 
vulcanite  plate  for  their  retention,  as  illustrated  in  Fig.  854,  has  long 
been  a  favorite  with  many.  Its  greatest  objection,  as  with  all  removable 
retainers,  is  the  uncertainty  of  its  being  worn  by  the  patient.  The 
lingual  arch,  for  the  same  purpose,  is  preferred  by  many.  It  should 
be  elastic,  and  to  avoid  injiny  by  heating  should  be  made  of  iridio- 
platinum  or  some  of  the  combinations  of  j)recious  metals. 

Fig.  854 


There  are  many  ways  of  attaching  it,  two  of  which  are  shown  in 
Figs.  855  and  856. 

Still  another  manner  of  using  the  lingual  arch,  which,  especially 
during  the  latter  stages  of  retention,  has  become  a  favorite  with  the 
writer,  is  shown  in  Fig.  857.  It  is  made  in  three  sections  and  soldered 
to  the  ends  of  screws  of  clamp-bands  which  latter  are  afterward  cemented 


Fig.  855 


Fig.  856 


and  clamped  upon  the  molars.  Delicate  spurs  of  soft  wire  may  be 
soldered  to  the  lingual  wire,  then  passed  through  the  interproximal 
spaces  between  the  incisors  and  bent  to  bear  against  the  angles  of  these 
teeth  to  prevent  their  rotation,  and  then  clipped  off.  Or,  the  incisors 
may  be  supported  by  bands,  spurs,  and  ligatures  which  engage  them 
with  the  lingual  segment  of  the  arch. 


RETENTION  799 

In  tlie  very  p:reat  tissue  changes  that  have  taken  place  in  all  such 
cases  as  the  one  described  on  page  732  (Huning),  it  must  be  apparent 
that  there  is  a  vast  amount  of  tearing  down  of  i)one  by  the  osteoclasts, 
and  its  rebuilding  by  osteoblasts,  as  well  as  similar  cellular  and  structural 
changes  of  the  other  tissues  involved.  Very  naturally,  and  a  fact  proved 
by  experience,  these  changes  are  most  active  and  the  growth  of  bone 

Fig.  857 


most  pronounced  in  cases  treated  during  the  active  period  of  growth 
and  development  of  the  dental  apparatus,  this  activity  naturally  dim- 
inishing with  the  advancing  age  of  the  patient,  necessitating  longer 
periods  of  retention  as  the  patient  nears  maturity,  and  after  maturity 
the  development  is  very  slow  and  probably  never  complete. 

With  a  view  to  expediting  the  treatment  of  malocclusion,  by  short- 
ening the  period  of  retention  in  theKse  cases,  the  writer  has  devised  a 


800 


ORTHODONTIA 


method  of  retention  hy  which  lie  believes  the  cells  involved  in  these 
tissue  changes  will  he  gently  stinmluted  to  greater  activity,  with  the 
more  speedy  and  complete  development  of  the  tissues. 


Fig.  858 


The  device  is  shown  in  Figs.  858  and  859,  and  is  for  the  purpose  not  only 
of  supporting  the  crowns  of  the  teeth  in  their  corrected  relations  with 
the  line  of  occlusion,  but  also  to  exert  a  very  gentle  but  constant  force 


.  Fig.  859 


labially  upon  the  roots  of  the  incisors.     It  may  be  regarded  as  a 

"working  retainer,"  as  appropriately  named  by  Dr.  George  B.  Palmer. 

The  device  is  made  by  removing  the  segment  between  the  threaded 

ends  of  the  expansion  arch  that  was  employed  in  accomplishing  the 


RETENTION  ^01 

movements  of  the  teetli,  and  substituting  for  it  a  segment,  of  the  same 
length  and  curve,  of  very  delicate  and  elastic  wire  of  precious  metal, 
attaching  the  ends  of  this  wire  to  the  threaded  ends  of  the  original 
arch  with  22  k  gold  solder. 

Small  tubes  are  soldered  perpendicularly  to  the  labial  surfaces  of 
delicate  iridioplatinura  bands  previously  very  carefully  fitted  to  the 
crowns  of  the  incisors.  These  tubes  must  be  parallel  with  each  other, 
with  their  incisal  ends  resting  in  contact  with  the  middle  segment  of  the 
arch. 

Very  delicate  spurs,  of  the  length  and  diameter  of  the  bore  of  the 
tubes,  are  soldered  to  the  arch  at  points  opposite  the  mouths  of  the 
tubes  and  at  angles  exactly  corresponding  to  the  bore  of  the  tubes  when 
the  arch  is  in  position.    The  ends  of  the  spurs  are  then  gently  inclined 

Fig.  860 


forward  about  one-sixteenth  of  an  inch  by  bending,  the  arch  replaced 
upon  the  teeth,  and  the  spurs  sprung  into  the  tubes.  Thus,  a  gentle 
force  from  the  elasticity  of  the  spurs  and  arch  is  given  to  the  roots  of 
the  teeth  in  a  labial  direction,  while  the  crow^ns  are  given  stationary 
support  in  all  directions.  The  spurs  are  prevented  from  accidental  dis- 
placement by  filing  a  hook-like  notch  near  the  end  of  the  spur  which 
engages  the  end  of  the  tube  when  sprung  in  position. 

The  writer  believes  that  such  a  gentle,  harmless  stimulus  is  thus 
given  as  will  accelerate  cellular  activity  and  greatly  lessen  the  time 
usually  necessary  for  bone  growth  and  retention,  besides  eft'ecting  final 
results  in  bone  development  which  would  otherwise  be  impossible 
when  the  patient  is  nearing  maturity. 

The  importance  of  the  device  has  been  verified  in  a  case  reported 
by  Dr.  A.  H.  Ketcham  (Fig,  861),  which  shows  the  result  in  bone 
51 


802  ORTHODONTIA 

growth  after  six  months'  wearing  of  the  device,  Fig.  SfiO,  showing  the 
alveolar  process  at  the  time  the  device  W'as  adjusted. 

As  the  alveolar  process  is  developed  and  the  apices  of  the  roots  of 
the  teeth  are  moved  labially,  it  is  occasionally  necessary  to  renew  the  force 
hy  further  outward  bending  of  the  spurs,  and,  in  order  to  avoid  the 
necessity  of  removing  the  arch  and  the  possi})le  accident  of  its  unfavor- 
able bending,  the  writer  recommends  that  a  portion  of  the  centre  of  the 
tubes  be  removed  with  a  round  file,  as  shown  in  the  engraving.  The 
arch  may  then  be  sprung  slightly  downward,  the  ends  of  the  spurs 
caught  with  a  delicate  excavator  where  the  tubes  are  cut  away  for  the 
purpose,  and  given  the  necessary  bend,  then  the  spurs  sprung  back  into 

Fi<;.   861 


position.  This,  however,  should  not  be  done  oftener  than  once  in  one 
or  two  months. 

By  studying  the  possibilities  of  this  device  it  will  be  seen  that  we 
have  absolute  control  over  the  development  of  the  positions  of  the  teeth 
in  their  entirety — far  more  so  than  by  the  use  of  any  other  known  device: 

First,  the  most  perfect  support  is  given  to  the  crowns  of  the  teeth  in 
all  directions. 

Second,  the  crowns  may  be  shifted  labially  or  lingually,  by  tightening 
or  loosening  the  nuts  in  front  of  the  tubes  of  the  anchor  bands. 

Third,  the  positions  of  the  roots  of  the  teeth  may  be  developed  labially 
or  lingually,  mesially  or  distally,  by  gentle  force  from  the  proper  bending 
of  the  spurs,  independent  of  the  position  of  the  crowns. 

Fourth,  force  for  rotation  or  for  the  prevention  of  rotation  of  any  of 
the  teeth  may  be  given  by  partially  flattening  the  ends  of  the  delicate 
spurs  and  the  ends  of  the  tubes  in  which  they  are  engaged,  then  giving 
the  spurs  a  slight  twist,  and  respringing  them  into  position. 


RETENTION 


803 


Atul  finally,  all  of  the  teeth  may  at  the  same  time  be  lengthened,  if 
so  desired,  by  giving  the  necessary  downward  spring  to  the  segment 
of  the  arch. 

In  like  manner,  support  and  movement  may  be  given  to  the  canines 
and  premolars,  if  desired,  and,  by  drilling  through  the  sheaths  of  the 
tubes  of  the  anchor  bands  and  the  sides  of  the  threaded  portion  of  the 
arch  and  inserting  delicate  keys  therein,  force  may  be  exerted  through 
the  elasticity  of  the  arch  for  the  movements  of  the  molar  roots,  either 
buccally  or  lingually. 

In  making  use  of  this  device  the  arch  may  be  placed  above  the  tubes 
instead  of  below  them,  as  shown,  or,  in  favorable  cases  where  the  occlu- 
sion will  permit,  the  arch  may  be  placed  lingually  to  the  teeth,  with  the 
tubes  either  parallel  with  or  at  right  angles  to  the  long  axes  of  the  teeth. 
But,  all  things  considered,  the  position  given  the  device  in  the  engraving 
will  be  found  to  be  the  most  satisfactory. 

It  is  also  equally  applicable  to  the  lower  dental  arch. 

This  device  may  be  operated  either  as  a  regulating  or  retain- 
ing appliance,  or  both,  as  its  name  implies.  The  writer  believes 
its  greatest  usefulness  will  be  as  a  bone  stimulant,  and  when  so  used 
should  be  made  very  delicate,  as  described,  so  that  only  such  gentle  force 
will  be  given  to  the  roots  of  the  teeth  as  will  physiologically  stimulate 
the  bone  cells.  Great  force  and  rapid  movement  of  the  apices  of  the 
roots  of  the  teeth  the  writer  believes  to  be  unphysiological. 


Fig.  862 


Retention  of  Cases  Belonging  to  Class  II. — In  the  retention  of  cases 
belonging  to  Class  II  the  principal  problem  is  to  resist  the  mesial 
movement  of  the  teeth  of  the  upper  arch  and  the  distal  movement  of 
those  of  the  lower  arch,  especially  the  canines,  premolars,  and  molars. 
If  there  have  been  movements  of  individual  teeth  in  other  directions, 
as  torsally,  labially,  etc.,  their  movements  may  be  resisted  by  methods 
which  we  have  previously  described  for  the  retention  of  teeth  in  cases 
belonging  to  Class  I. 

Our  principal  reliance  is  the  application  of  force  reciprocally  between 
the  teeth  of  opposing  arches  by  means  of  intermaxillary  retainers,  shown 


804 


ORTHODONTIA 


in  Fig.  <SG2,  This  retainer  is  susceptible  of  numerous  modifications 
to  meet  the  recjuirements  in  different  cases. 

It  consists  of  a  strong'  spur  made  to  close  in  front  of  a  ])lane  of  metal, 
both  soldered  to  No.  2  bands,  which  are  clamj)ed  in  cement  on  oj^posing 
molars. 

The  plane  of  metal,  best  cut  from  a  silver  ten-cent  piece,  should  be 
about  one-fourtii  of  an  inch  long  and  one-eighth  of  an  inch  wide,  and 
rounded  on  its  distal  angle. 

The  spur  is  best  made  of  nickel  silver,  about  three  thirty-seconds  of 
an  inch  in  diameter. 

The  stress  upon  this  device  is  often  very  severe,  and  unless  carefully 
made  and  properly  cemented  upon  the  teeth  it  will  give  trouble  by 
loosening. 

Bands  of  the  best  cjuality  should  be  carefully  fitted  to  the  molars, 
and  at  their  union  with  plane  and  spur  should  be  strongly  reinforced 
with  plenty  of  solder,  care  being  taken  not  to  weaken  the  bands  by  over- 
heating. 

Both  bands  should  be  placed  as  near  the  grinding  surfaces  of  the 
crowns  of  the  teeth  as  possible,  without  interfering  with  occlusion,  and 
the  plane  attached  low  down,  or  at  the  very  edge  of  the  upper  band,  and 
the  spur  attached  as  high  up  as  possible  on  the  lower  band.  In  this 
way  the  spur  is  shortened  and  the  leverage  decreased,  with  the  con- 
sequent danger  of  loosening  minimized.  The  spur  should  always 
engage  the  plane  on  an  incline,  as  shown  in  the  engraving.  It  may 
occasionally  be  necessary  to  shift  the  position  of  the  plane  mesially  or 
distally  by  resoldering  to  meet  the  requirements,  as  retention  progresses. 


Fig.  863 


Fig.  864 


Fig.  865 


E.   H.   A. 


E.  H.  A. 


E.  H.   A 


This  method  of  intermaxillary  retention  is  also  applicable  to  pre- 
molars and  canines,  as  shown  in  Figs.  863  and  S64.  It  may  be  used  on 
these  teeth  in  connection  with  molar  retention,  or  independently,  as 
occasion  may  require.  It  is  often  desirable  to  alternate  from  one  to  the 
other.  The  device  as  shown  in  Fig.  808  is  incorrect,  the  spur  shown, 
as  being  perpendicular  instead  of  engaging  the  plane  on  a  slight  incline. 

When  made  use  of  upon  the  canine  teeth  no  band  or  plane  of  metal 
is  needed  on  the  opposing  (upper)  canine,  as  the  mesial  incline  of  the 


RETENTION  805 

cusp  of  this  tooth  is  taken  advaiitaf^e  of.  The  flat  spur  should  be  grooved 
on  its  edge  to  make  more  secure  its  relation  with  the  upper  canine. 

It  should  incline  somewhat  forward  to  be  most  effective,  and  if 
occasional  adjustment  is  necessary,  this  may  easily  be  done  by  bending, 
to  make  its  bearing  upon  the  upper  canine  more  effective.  In  this  way 
not  only  retention,  but  the  actual  movement  of  the  upper  canine  distally 
and  the  lower  canine  mesially,  may  be  accomplished  to  some  extent, 
and  in  many  cases  this  is  very  desirable. 

Owing  to  the  unfavorable  shape  for  banding  of  the  lower  canine 
tooth,  there  is  more  liability  of  bands  upon  these  teeth  loosening 
under  strain  than  those  upon  the  premolars.  They  should  therefore 
be  made  with  the  greatest  care,  always  using  H  band  material,  and 
securing  the  most  perfect  fit.  This  spur  is  also  best  made  from  a 
silver  ten-cent  piece.     The  band  is  illustrated  in  Fig.  865. 

In  rare  instances  spurs  set  in  fillings  for  accomplishing  the  same  pur- 
pose in  retention  will  be  found  desirable,  and  Dr.  Stanton  makes  use 
of  a  crown  covering  a  tooth,  which  is  fitted  with  an  inclined  plane  at  the 
desired  point  to  engage  the  opposing  cusp.  The  device  would  be  effi- 
cient and  especially  applicable  to  the  deciduous  teeth,  where  the  necessary 
reduction  of  the  crown  of  the  tooth  in  order  to  properly  fit  the  metal 
cap  would  be  permissible. 

Fig.  866 


The  writer's  plan  of  intermaxillary  retention  has  been  ingeniously 
modified  by  Dr.  Griinberg,  as  shown  in  Fig.  866,  and  as  in  the  use  of 
this  device  the  strain  upon  band  and  spur  is  quite  equally  divided,  it 
will  undoubtedly  prove  very  efficient. 

For  maintaining  the  proper  width  of  the  upper  dental  arch  in  the 
region  of  the  premolars  and  to  prevent  the  labial  movement  of  the  incisors 
which  have  been  moved  lino-uallv  in  cases  belongins:  to  Division  1  of 
Class  II  and  its  subdivision,  the  lingual  wire  arch,  shown  in  Fig.  857, 
is  a  favorite  with  the  writer,  in  these  cases  taking  advantage  of  the  molar 
clamp  bands  that  bear  the  planes  of  metal.  The  lingual  arch  here  serves 
also  another  purpose,  giving  additional  support  to  the  molars. 

Very  delicate  gold  bands  encircle  the  incisors.  They  are  provided 
with  delicate  hooks  or  staples  on  their  lingual  surfaces  for  securing 
their  attachment  to  the  arch  by  means  of  wire  ligatures.     The  WT-iter 


806 


ORTHODONTIA 


employs  this  means  of  attachiiieiit  of  the  incisors  in  preference  to  the 
innnediate  en^'agenient  of  the  arch  to  the  l)ands  by  solder,  tubes,  or 
spurs,  as  it  admits  of  an  easier  adjustment  and  better  control  over  the 
positions  of  these  teeth,  althou<:jh  some  prefer  hooks  or  staples  soldered 
to  the  bands  which  directly  engage  the  arch.  Still,  in  many  instances  the 
writer  prefers  the  simple  wire  ligature  alone  for  securing  the  incisors 
to  the  arch,  making  the  twist  of  the  ligatures  lingually  to  the  teeth. 

Another  plan,  given  to  us  by  Dr.  Kingsley,  which  has  long  been  a 
favorite  with  many,  is  by  means  of  a  neatly  fitting  vulcanite  or  metal 
plate  which  covers  the  vault  of  the  arch,  shown  in  Fig.  867.  This 
prevents  the  narrowing  of  the  arch  and  also  provides  a  means  for  the 
support  of  a  screw  in  its  anterior  part.  The  screw  is  beaten  thin  where  it 
passes  between  the  central  incisors,  and  is  provided  with  a  small  button  or 
cross-bar  soldered  to  the  end  of  the  screw  which  is  made  to  l)ear  against 


Fig.  867 


the  labial  surface  of  the  two  central  incisors.  This  is  an  efficient  retainer, 
but  the  danger  of  its  not  being  worn  constantly  by  the  patient  makes 
its  use  far  less  desirable  than  that  of  a  fixed  device,  yet  it  has  long  been 
a  favorite  with  the  writer  in  the  last  stages  of  retention.  When  u.sed 
in  connection  with  intermaxillary  retention,  the  plate  must  be  freely 
cut  away  to  avoid  interference  with  the  screws  of  the  damp-bands. 

The  working  retainer,  described  on  page  <S()0  (Figs.  858  and  859), 
may  also  be  used  with  much  satisfaction  for  retaining  the  incisors  in 
some  cases  belonging  to  this  class. 

A  device  which  may  occasionally  be  used  to  advantage  for  resisting 
the  labial  and  lengthening  movements  of  the  upper  incisors  is  etiected 
by  placing  upon  the  lower  central  incisors  plain  bands,  having  soldered 
to  their  labial  surfaces  strong  spurs  which  project  forward  and  are  bent 
upward  sharply  at  right  angles  to  engage  the  labio-occlusal  edges  of 
the  upper  incisors,  as  shown  on  one  tooth  in  Fig.  868.     The  stability 


RETENTION  807 

of  the  teeth  used  as  anchorage  should  he  reinforced  hy  a  section  of  the 
wire  G,  soldered  across  the  lingual  surface  of  their  hands  and  made  to 
bear  against  the  adjoining  lateral  incisors. 

Sometimes  it  may  he  desirable  to  place  the  bands  upon  the  canines 
instead  of  upon  the  incisors,  and  connect  them  by  a  bar  of  metal  con- 
taining the  retaining  spurs,  Fig,  S69. 

If  the  reader  will  study  this  device  he  will  observe  that  in  its  use 
not  only  is  normal  closure  of  the  jaw  compulsory,  but  that  the  incisors 
are  kept  compressed  in  their  sockets  and  prevented  from  moving  labially 
as  well.  Still  another  advantage  of  no  small  importance  is  gained  in 
preventing  the  lower  lip  from  being  drawn  against  the  lingual  surfaces 
of  the  upper  incisors,  a  habit  which  seems  to  be  almost  universal  in 
these  cases,  and  difficult  but  most  necessary  to  overcome. 

For  the  second  division  of  Class  II  and  its  subdivision  the  plan  of  reten- 
tion for  the  molars,  premolars,  and  canines  is  the  same  as  that  already 
described  for  the  retention  of  these  teeth  in  Division  1,  Class  II,  and  its 
subdivision. 

Fig.  868  Fig.  869 


E.  H.  A. 


As  the  upper  incisors  in  Division  2  are  usually  more  or  less  crow^ded, 
rotated,  and  retruded  in  their  relation  to  the  line  of  occlusion,  their 
requirements  for  movement,  as  well  as  the  problems  in  their  retention, 
are  practically  the  same  as  for  cases  in  which  these  teeth  occupy  similar 
malpositions  in  Class  I.  So  their  movements  are  readily  combated  by 
similar  combinations  of  bands  and  spurs,  as  are  also  the  anterior 
teeth  of  the  lower  arch.  The  working  retainer  may  also  be  used  in  these 
cases,  especially  when  there  is  found  to  be  lack  of  development  of  the 
bone  in  the  region  of  one  or  more  of  the  incisors. 

Retention  for  Cases  Belonging  to  Class  III. — As  in  Class  III  the  m.ove- 
ments  of  the  molars,  premolars,  and  canines  of  both  arches  are  the 
reverse  of  the  movements  of  these  teeth  in  Class  II,  the  same  plan  of 
ntermaxillary  retention,  with  the  direction  of  force  reversed,  is  employed, 
the  spurs  on  the  lower  molars  operating  against  the  distal  ends  of  the 
planes  on  the  opposing  teeth.  It  is  frequently  advisable  to  place  the 
spur  on  the  upper  molars  and  the  plane  on  the  lower,  in  which  case 
the  spur  operates  against  the  mesial  end  of  the  plane.  Dr.  Griinberg's 
excellent  modification  of  the  plane  and  spur,  previously  described,  will 
also  be  found  very  applicable. 


808  ORTHODONTIA 

The  same  results  may  he  acc()in])lislK'd  in  simple  ("lass  III  cases 
of  very  youii^  })atieiits  by  means  of  plain  bands  carefully  fitted  to  and 
cemented  on  the  uj)j)er  central  incisors,  the  bands  having  sj)urs  soldered 
to  their  lingual  surfaces  which  project  downward  and  forward  to  engage 
the  labial  surfaces  of  the  lower  incisors,  thus  compelling  the  normal 
closure  of  the  jaw  and  normal  mesio-distal  relations  of  the  tt^eth. 

When  individual  movements  of  any  of  the  anterior  teeth  have  been 
accomplished  they  are  retained  l)y  the  application  of  bands  and  spurs 
in  some  of  their  combinations,  as  would  be  employed  in  similar  problems 
found  in  Class  I. 

The  application  of  these  principles  of  retention  will  be  further  dis- 
cussed in  the  treatment  of  individual  cases. 


TREATMENT 

Preliminary  Considerations.^ — Before  beginning  treatment  of  mal- 
occlusion of  the  teeth  there  should  be  certain  well-defined  principles 
fixed  in  our  minds  in  regard  to  the  dental  apparatus  as  a  whole,  for 
we  must  constantly  bear  in  mind  the  intimate  relations  existing  between 
the  teeth  and  all  other  tissues  and  parts  of  the  dental  apparatus,  and 
the  powerful  influences  they  exert  upon  one  another.  We  have  seen 
that  nature  builds  the  human  denture  in  accordance  with  her  long- 
tried  and  well-established  laws,  the  result  being  a  constant  and  well- 
defined  pattern;  that  this  pattern,  although  varied  in  form,  is  in  principle 
always  the  same;  and  that  its  variations  are  always  in  harmony  with 
the  demands  of  the  type  of  the  individual. 

W'e  have  already  noted  that  when  nature,  through  certain  adverse 
causes,  is  unable  to  fully  carry  out  her  normal  processes  in  the  building 
of  the  dental  apparatus,  there  are  in  the  result  defects  or  variations  from 
the  normal  plan,  shown  in  malocclusion  of  the  teeth,  with  consequent 
impairment  of  their  functions — the  extent  of  the  malocclusion  being  in 
direct  proportion  to  the  extent  of  the  disturbing  cause^ — the  perversion 
of  the  forces  which  are  operative  in  building  the  normal  denture.  Also, 
in  the  same  proportion  as  malocclusion  exists,  will  there  be  disturbance 
in  the  harmony  and  balance  of  the  mouth  with  the  rest  of  the  face. 

The  longer  teeth  remain  in  malocclusion  the  more  fixed  becomes 
the  variation  from  the  normal  in  all  co-related  muscles  and  tissues. 
I^ogically,  then,  in  the  treatment  of  malocclusion  our  attention  should 
})e  directed  toward  interpreting  nature's  designs  and  assisting  her  to 
carry  out  her  original  plan  in  the  building  of  the  denture,  working  hand 
in  hand  with  her,  for  only  as  we  comprehend  her  intent  in  each  individual 
case  and  assist  her,  will  our  efforts  be  successful  in  establishing  the 
normal  in  occlusion  and  the  normal  in  the  balance  of  the  mouth  with 
the  rest  of  the  face.    It  should  be  obvious,  then,  to  all  thoughtful  minds, 


THE  A  TMENT  809 

that  the  (kMiiaiul  in  ti-catnu-nt  is  the  removal  of  ])erniciou.s  causes, 
the  retention  of  the  full  conijjlenient  of  teeth,  and  the  compellin^f  of 
their  normal  loekinii;  duiiu^-  or  sul)sef|uent  to  their  normal  j^eriod  of 
eruption,  thus  permitting  nature  to  complete  the  denture  and  the 
co-related  parts  according  to  her  fixed  plan  and  the  demands  of  the 
individual  tyj^e.  It  is  also  obvious  that  the  earlier  our  efforts  at  treat- 
ment are  begun,  the  better  we  will  be  able  to  assist  nature,  and  the 
more  satisfactory  will  be  the  results. 

The  method  so  long  followed  of  determining  an  arbitrary  course  of 
treatment  for  each  individual  case  "according  to  the  judgment  of  the 
operator,"  in  which  extraction  is  freely  resorted  to,  and  the  sizes  of 
arches  o'reatlv  reduced  and  their  forms  modified  from  nature's  intended 
plan  and  the  demands  of  the  type,  has  ever  resulted,  and  can  only 
result,  in  establishing  the  abnormal — deformity.  By  such  treatment, 
instead  of  greater  freedom  being  given  to  the  tongue  and  normal  function 
to  the  teeth,  the  former  is  often  more  restricted  and  the  function  of  the 
latter  upon  the  whole  rarely  improved;  and  instead  of  establishing  bal- 
ance, harmony,  and  beauty  of  the  facial  lines,  the  deformity  is  ultimately 
more  often  found  to  have  been  only  modified,  with  a  result  even  far 
less  pleasing  than  the  original  condition. 

While  in  most  instances  we  may  rapidly  estal:»lish  the  normal  sizes 
of  the  arches  and  relations  of  the  teeth,  much  time  will  often  be  required 
by  nature  to  effect  the  normal  development  of  the  other  tissues  of  the 
dental  apparatus,  the  development  of  which  has  been  arrested.  Yet 
even  in  this  we  may  often  greatly  assist  nature  by  directing  our  patients 
as  to  the  proper  and  necessary  closure  of  their  lips  and  teeth,  and  proper 
breathing,  and  by  insisting  upon  their  overcoming  pernicious  habits 
of  the  lips  and  tongue,  and  also  insisting  upon  treatment  of  nose  and 
throat  when  needed.  These  conditions  often  call  for  much  tact  and 
persistent  patience  on  the  part  of  the  orthodontist. 

What  we  have  said  presupposes  the  treatment  of  cases  with  the  full 
complement  of  teeth,  which  we  have  had  the  opportunity  to  treat  during 
their  most  active  period  of  growth,  development,  and  eruption,  or  during 
the  period  in  which  lie  our  greatest  opportunities  for  assisting  nature  in 
approximating  the  nearest  to  the  ideal  in  the  results.  Yet  many  cases 
are  presented  for  treatment  in  which  there  is  a  lack  of  the  full  comple- 
ment of  teeth,  through  failure  to  develop,  extraction,  or  caries.  The 
demands  for  the  great  object  to  be  accomplished,  however,  are  the  same 
in  these  cases  as  when  the  full  complement  of  teeth  is  present,  and 
necessitates  the  establishing  of  normal  occlusion,  or  as  nearly  so  as  the 
exigencies  of  the  case  will  permit,  by  enlarging  the  dental  arches  to 
their  normal  size  and  replacing  the  missing  teeth  by  artificial  substi- 
tutes. While  this  ideal  treatment  may  not  always  be  deemed  advisable, 
it  is  impossible  to  lay  down  any  rules  for  such  exceptions. 

The  carrying  out  of  the  ideal  in  the  treatment  of  such  cases  presents 


810  ORTHODONTIA 

such  apparently  great  difficulties  that  it  would  probably  be  the  last 
one  to  which  the  amateur  in  orthodontia  would  naturally  resort.  He 
would  be  inclined  to  compensate  for  the  already  diminished  size  of  one 
arch  by  reducing  the  size  of  the  opposing  arch  l)y  extraction.  Yet 
the  great  difficulty  of  permanently  maintaining  the  teeth  in  correct 
alignment  when  so  treated  must  not  be  lost  sight  of,  for  it  must  be 
remembered  that  inclined  occlusal  planes,  inharmonious  as  to  size  and 
form,  are  thus  brought  in  contact,  with  teeth,  also,  at  incorrect  angles 
of  inclination,  thus  tending  toward  their  displacement  from  wrongly 
distributed  force  in  occlusion,  instead  of  occlusal  planes  harmonious  as 
to  size  and  relation  with  normal  angle  of  inclination  of  teeth,  as  intended 
by  nature,  which  favors  permanency  of  normal  positions  and  relations. 
Moreover,  by  the  reduction  of  the  sizes  of  the  dental  arches,  the  tongue 
and  lips  must  exercise  less  control  in  keeping  the  teeth  in  correct  posi- 
tions than  when  exerting  their  full  normal  influence,  as  when  the  full 
number  of  teeth  is  correctly  placed.  Furthermore,  the  invariable 
detrimental  effect  on  the  facial  lines,  the  shortening  of  the  bite,  and 
the  impairment  of  speech,  make  this  plan  of  treatment  so  objectionable 
that  it  is  rarely,  indeed,  that  the  skilful,  modern  orthodontist  would 
resort  to  it,  for  the  great  perfection  to  which  the  regulating  appliances 
have  been  brought  makes  easily  possible  the  enlarging  of  the  dental 
arches  and  the  regaining  of  the  spaces  for  the  full  mesio-distal  diameter 
of  malposed  or  missing  teeth.  This  fact,  together  with  the  ease  and 
permanency  with  which  missing  teeth  are  replaced,  owing  to  the  great 
advancement  in  modern  prosthetic  art,  makes  this  the  one  plan  of 
practice  that  will  be  more  and  more  appreciated  by  the  true  orthodontist 
as  his  knowledge  and  experience  increase;  yet  in  the  cases  of  very 
young  patients,  where  there  has  been  mutilation,  it  is  often  difficult 
to  decide  which  of  the  two  plans  to  follow,  the  serious  problem  hinging 
upon  the  result  of  mutilating  sound  teeth  in  order  to  restore  missing 
teeth  by  artificial  substitutes.  Still,  if  it  were  always  possible  to  have 
the.se  restorations  made  with  a  very  high  degree  of  skill,  with  mutilation 
reduced  to  the  minimum,  the  conservative,  ideal  plan  of  treatment 
would   be   universally   desirable. 

Treatment  of  Cases. — Class  I.— As  we  have  already  noted  in  the  classi- 
fication of  malocclusion,  the  number  of  cases  belonging  to  this  class  is 
the  greatest  and  comprises  by  far  the  largest  variety,  the  distinguishing 
characteristic  of  the  class  being  relative  normal  relations  of  the  jaws, 
with  molars  in  correct  relation  mesio-distally,  although  one  or  more 
may  be  in  buccal  or  lingual  occlusion.  The  malposed  teeth  are  usually, 
however,  confined  to  those  anterior  to  the  molars,  and  more  commonly 
to  the  incisors  and  canines,  the  dental  arches  being  smaller  than  normal 
and  the  teeth  crowded  and  overlapping.  Both  arches  are  usually  involved, 
and  sometimes  quite  similarly. 

As  the  mesio-distal  relations  of  the  lateral  halves  of  the  dental  arches 


TREATMENT 


811 


are  normal  in  this  class,  it  must  follow  that,  if  the  malposed  teeth  of 
each  arch  be  moved  into  harmony  with  the  line  of  occlusion,  the  arches 
must  then  he  in  perfect  harmony  as  to  size,  with  harmony  of  the  occlusal 
inclined  planes  of  the  cusps — normal  occlusion—and  with  proper  facial 
balance  established.  The  latter,  however,  may  not  at  once  be  apparent, 
as  we  shall  see  later,  but  it  must  follow  ultimately  when  nature  shall 
have  effected  the  full  development  of  the  alveolar  process 
and  the  muscles  shall  have  become  modified  in  form  and 
function  so  as  to  act  normally  in  their  relation  with  the 
teeth  in  occlusion. 

To  illustrate.  Fig.  870  represents  a  type  of  malocclusion 
which,  in  its  variations,  is  common  in  this  class.  It  will 
be  seen  that  the  mesial  and  distal  inclined  planes  of  the 
mesio-buccal  cusp  of  the  upper  first  molar  on  the  right 
are  received  between  the  inclines  of  the  mesio-  and  disto- 
buccal  cusps  of  the  lower  first  molar,  or  that  the  relations 
of  the  first  molars  are  normal.  (The  molars  of  the  oppo- 
site side  were  also  in  normal  relation.)  The  arches  are 
diminished  in  size,  and  the  teeth,  especially  the  incisors, 
occupy  positions  lingual  to  the  line  of  occlusion.  What  is  then  clearly 
indicated  is  that  the  arches  should  be  enlarged  and  each  tooth  moved 
into  its  correct  position  in  the  line  of  occlusion,  as  showm  in  the 
case  when  completed  (Fig.  871),  and  in  the  plan  of  treatment  of 
any  case,  as  has  been  said,  it  makes  but  little  difference  what 
positions  the  malposed  teeth  may  occupy,  they  are  always  subject  to 

Fig.  870 


E.  H.  A, 


the  same  general  requirement.  In  the  completed  case,  as  shown  in 
Fig.  871,  it  will  be  seen  that  each  tooth  has  been  placed  in  harmony 
with  the  line  of  occlusion,  and  is,  therefore,  now^  in  best  position  to 
support  and  be  supported  by  all  the  remaining  teeth,  as  well  as  to  be 
in  best  harmony  with  the  muscles  and  to  make  possible  the  normal 
balance  of  the  facial  lines. 


812 


ORTHODONTIA 


Fio-.  S72  shows  one  of  llic  most  (•oin})lic'a(o(l  types  of  cases  lielon^iiifi; 
to  this  class.  The  teeth  of  both  hiteral  halves  of  the  iij)})er  arch  are  in 
lingual   occlusion,  the    ui)i)er  arch    p'catly    narrowed    and    diminished 


in  size,  with  the  laterals  in  marked  torsolingual  occlusion,  and  the 
centrals  in  torsal  occlusion,  while  the  great  force  received  upon  the 
molars,  being  wrongly  distributed,  has  resulted  in  displacing  all  the 
buccal  teeth  of  the  upper  arch  bodily  lingually,  the  apices  of  the  roots  as 


Fig.  872 


well  as  the  crownis,  with  the  opposite  effect  on  the  opposing  teeth,  thus 
greatly  narrowing  the  upper  jaw,  dental  arch,  and  nasal  space,  and 
widening  the  lower  jaw,  giving  a  peculiar  bagginess  to  the  lower  part 


TREATMENT 


.si;j 


of  the  face  always  noticeable  in  tliese  cases.  They  are  always 
progressive,  usually  beginning  with  the  mal-locking  of  the  first  perma- 
nent molars,  but  sometimes  preceded  l)y  similar  malocclusion  of  the 
deciduous  teeth. 

Fig.  873 


Had  the  first  permanent  molars  received  but  a  fev^  hours'  attention  on 
coming  into  occlusion  and  been  compelled  to  take  their  normal  relations, 
doubtless  the  malocclusion  would  have  ended  there,  and  the  eruption 
of  the  teeth  and  development  of  the  alveolar  process  subsequent  to  this 


Fig.  874 


would  have  been  along  normal  lines.  Yet  many  dentists  still  persist 
in  advising  parents  to  defer  treatment  of  their  children's  malocclusion 
until  all  of  the  teeth  have  erupted. 

The  line  of  treatment  was  toward  the  ideal,  widening  the  upper 
arch,  correcting  the  malpositions  of  the  incisors,  and  narrowing  the 
lower  arch. 


814 


ORTHODONTIA 


Fig.  874  shows  the  upper  arch  l)ein^  widened  by  means  of  the  expan- 
sion arch,  adjusted  in  the  usual  way,  and  reinforced  l)y  one  of  the 
sprin<;  levers,  L,  the  incisors  being  moved  forward  r//  wr/.s-.sr  and  rotated 
by  means  of  s])urre(l  bands,  ligatures,  etc.,  all  as  shown  and  described 
in  the  section  on  Adjustment  and  ()j)eration  of  Appliances. 


P'lc.   87") 


The  narrowing  of  the  lower  arch  was  effected  by  means  of  a  device 
manufactured  for  the  occasion  and  shown  in  Fig.  873;  but  the  recent 
practice  of  the  writer  is  to  narrow  the  dental  arches  in  such  cases  with  the 
expansion  arch  (ribbed),  it  having  been  found  that  it  develops  ample 
force  for  this  purpose. 

Fig.  876 


In  making  use  of  the  ribbed  arch,  as  above,  it  is  only  necessary  to 
compress  its  sides  so  that  they  are  perhaps  two-thirds  the  width  of 
the  dental  arch  to  be  narrowed,  and  insert  the  ends  in  the  sheaths  of  the 
D  bands,  as  usual,  care  being  taken  to  retain  all  of  the  spring  in  the 


TREATMENT 


815 


lingual  direction  possible.  The  arc-h  is  prevented  from  springing  forward 
by  being  secured  to  the  incisors  by  one  or  more  ligatures.  Although  its 
action  is  slow,  re(iuiring  several  weeks  in  a  patient,  aged  sixteen  years, 
the  writer  has  found  its  use  most  satisfactory. 

Fig.  875  shows  the  u{)per  arch  completed  and  the  retaining  devices 
in  position,  while  Fig.  876  shows  both  arches  completed  and  the  teeth 


Fir,.   S77 


in  occlusion.  The  lingual  tendency  of  the  upper  incisors  and  the  torso- 
infra-occlusal  tendencies  of  the  upper  canines,  as  well  as  the  lingual 
tendency  of  the  molars  and  premolars,  were  resisted  by  bands  on  the 
canines  connected  by  a  section  of  the  wire  G,  and  a  vulcanite  plate,  as 
illustrated.    The  bands  upon  the  canines  are  also  shown  in  Fig.  876, 


Fig.  878 


As  here  shown,  the  retaining  wire  rests  on  the  incline  of  the  lingual 
marginal  ridges  of  the  incisors.  It  should  bear  either  above  or  below 
this  incline,  for  if  allowed  to  rest  in  the  position  shown,  delicate  bands 
would  be  required  on  the  laterals,  at  least,  to  prevent  the  wire  from 
being  forced  toward  the  cutting  edges  of  the  teeth. 

The  lingual  retaining  arch,  as  shown  in  Fig.  857,  would  often  be 
preferable  to  the  bands  and  plate  in  such  cases,  and  the  working  retainer 


816 


ORTHODONTIA 


inio-ht  also  Ix-  used,  and  doubtless  in  many  similar  cases  would  l;e 
preferable. 

The  model  illustrated  in  Fig.  877  represents  a  case  where  one  only 
of  the  lateral  halves  of  the  upper  arch  was  in  lingual  occlusion.  The 
lateral  incisors  were  in  marked  torso-lingual  occlusion.  The  patient 
was  a  child,  aged  eight  years,  the  deciduous  molars  and  canines  being 
still  in  position. 

The  plan  of  treatment  clearly  indicated  was  widening  the  arch  by 
movement  buccally  of  the  teeth  on  the  affected  side  only,  with  labial 
movement  of  the  centrals  and  torso-labial  movement  of  the  laterals. 
Fig.  878  shows  a  view  of  this  arch  from  the  occlusal  aspect,  with  the 
appliances  for  accomplishing  these  movements  of  the  teeth  in  position. 

Fit;.  879 


It  will  be  seen  that  all  of  the  teeth  on  the  left  side  are  used  as  anchorage, 
and  that  their  combined  resistance  is  concentrated,  through  the  force 
distributed  by  the  external  and  internal  arches,  upon  the  left  first  per- 
manent molar.  But  a  few  days  were  necessary  to  move  this  tooth  into 
correct  position,  where  it  was  maintained  l)y  occlusion  and  the  modified 
(through  liending)  alveolar  j)rocess.  A  wire  ligature  was  then  made  to 
encircle  the  second  deciduous  molar  and  the  expansion  arch,  thus 
practically  transferring  the  force  to  this  tooth.  Later,  the  first  deciduous 
molar  was  moved  out  in  the  same  way.  The  object  of  moving  the  teeth 
one  at  a  time  was  to  avoid  overtaxing  the  anchorage  derived  from  the 
opposite  side  of  the  arch.    Had  the  effort  been  made  to  move  all  at  the 


TREATMENT 


S17 


same  time,  it  is  j)rol)al)le  that  the  teeth  on  the  normal  side  would  have 
been  displaeed  more  rapidly  than  those  on  the  abnormal  side,  on 
account  of  the  increased  resistance  offered  by  the  inlocking  of  the 
inclined  planes  of  the  cusps  of  the  molars  on  the  abnormal  side.  The 
writer's  latest  plan  for  avoiding  displacement  of  the  teeth  used  as 
anchorage  in  cases  of  this  kind  is  to  enlist  stationary  anc-horage  by 
uniting  the  sheath  of  the  clamp-band  and  the  threaded  portion  of  the 


arch  within  it  w  ith  soft  solder,  thus  recjuiring  the  displacement  of  the 
anchor  tooth  bodily,  if  moved  at  all.  It  will  be  readily  understood  how 
greatly  the  anchorage  would  be  thus  increased. 

^Yhile  the  appliances  were  acting  upon  the  abnormal  lateral  half  of 
the  arch,  the  incisors  were  carried  forward  and  rotated  by  bands, 
spurs,  and  ligatures,  with  notches  on  the  ribbed  expansion  arch  to  pre- 
vent slipping  of  the  wire  ligature,  the  movement  being  further  assisted 
by  the  tightening  of  the  nut  on  the  expansion  arch  on  the  affected  side. 
52 


818  ORTHODONTIA 

The  widened  arch  was  retained  by  a  vulcanite  plate  (Fip;.  <S54). 
The  mesial,  torsional,  and  lingual  tendencies  of  the  right  lateral  and 
the  lingual  tendencies  of  the  other  incisors  were  resisted  by  bands  upon 
the  laterals  connected  by  a  piece  of  wire,  G,  soldered  to  their  lingual 
surfaces.  Fig.  881  shows  the  occlusion  of  the  teeth  eight  years  after 
treatment.    The  facial  lines  were  practically  faultless. 

This  type  of  malocclusion  is  more  fre(|uent  among  children  than 
seems  to  be  commonly  sup})osed,  and  it  is  important  that  it  receive  early 
attention,  for  if  allowed  to  progress  the  mouth  must  inevitably  develop 
asymmetrically,  the  jaw  shifting  laterally,  giving  a  peculiar  twisted 
appearance  to  the  mouth. 

Fig.  881 


Ficjs.  879  and  880  illustrate  a  case  in  its  labial,  buccal,  and  occlusal 
aspects,  and  from  the  position  of  the  canines  and  that  of  the  mesio-buccal 
cusps  of  the  upper  first  molars  it  will  be  readily  recognized  as  a  typical 
case  belonging  to  the  first  class. 

It  will  be  seen  that  the  arches  are  much  shortened  and  reduced  from 
the  normal  size,  with  marked  lingual  positions  of  all  the  incisors,  the 
left  upper  lateral  being  in  contact  with  the  first  premolar,  causing  almost 
complete  labial  displacement  of  the  left  canine,  while  at  least  one-half 
of  the  space  necessary  for  the  right  canine  is  occujMed  by  the  right  lateral, 
the  influence  of  the  lips  effectually  maintaining  the  diminished  size 
of  the  arches  and  the  malocclusion. 

The  effect,  as  might  be  supposed,  was  very  noticeable  in  the  facial 
lines  of  the  patient,  as  shown  in  Fig.  732,  producing,  as  we  have  seen, 
a  pinched  and  flattened  appearance  about  the  mouth. 


TREATMENT 


819 


What  Wcas  clearly  imlicaied  was  to  j)la('e  all  the  malposed  teeth  in 
harmony  with  the  line  of  occlusion. 

Fio".  882  shows  the  various  necessary  tooth  movements  bein^  accom- 
plished in  both  arches  simultaneously  by  means  of  ribbed  expansion 
arches/  D  bands,  spurred  bands,  wire  ligatures,  etc.,  adjusted  and 
operated  as  described  in  the  section  on  Adjustment  and  Operation  of 
Appliances. 

The  anchorage  was  elfected  by  means  of  D  bands  placed  upon  the 
first  molars  in  the  lower  arch,  while  in  the  upper  arch  a  D  band  upon 
the  first  molar  was  used  on  the  right  side  and  an  X  band  on  the  first 


Fig    882 


premolar  on  the  left  side,  it  being  found  necessary  after  a  few  days  of 
treatment  to  transfer  the  anchorage  from  the  left  first  molar  to  this 
tooth,  as  the  molar  showed  displacement  distally  in  resisting  the  strain 
of  the  labial  movement  of  the  incisors.  It  is  not  surprising  that  the 
first  molar  did  show  weakness  of  anchorage  and  move  distally  in  this 
case,  as  it  may  in  all  cases  at  this  age,  for  the  reason  that  the  second 
molar  gives  it  no  support,  it  being  still  unerupted  and  lying  in  a  large 
open  crypt  into  which  the  first  molar  may  quite  readily  be  moved.  It  is 
usually  well  in  such  cases  to  reinforce  the  molar,  which  can  easily  be 
done  by  ligating  it  to  the  premolars. 


^  Several  of  the  cuts  shoeing  the  expansion  arch  were  made  before  the  invention 
of  the  ribbed  expansion  arch,  therefore  soldered  spurs  on  the  plain  arch  to  prevent 
the  slipping  of  the  ligatures  are  shown  instead  of  notches  in  the  ribbed  arch,  as  now 
used,  but  referred  to  in  the  text  as  though  the  notched  ribbed  arch  had  been  used. 


J^20  ORTHODONTIA 

It  will  he  noticed  that  there  are  two  ligatures  upon  the  left  lateral 
incisor  (upper).  One  is  a  j)lain  ligature,  as  in  A,  Fig.  SOT,  for  effecting 
the  lahial  movement;  the  second,  as  in  B,  Fig.  807,  encircles  the  arch 
and  a  spur  soldered  low  down  upon  the  lingual  surface  of  the  band 
upon  the  lateral.  The  office  of  this  ligature  was  partly  to  assist  in 
carrying  the  incisor  forward,  but  principally  to  effect  its  rotation.  A 
notch  in  the  rib  of  the  expansion  arch  prevented  this  ligature  from  slid- 
iniT  forward  and  directed  the  movement  of  the  tooth  laterally,  the  arch 
being  so  bent  that  in  shape  and  spring  it  bore  toward  the  left  and  favored 
this  movement,  assisted  reciprocally  by  the  band,  spur,  and  ligatures 
upon  the  right  lateral.  The  reason  for  the  spurs  being  placed  well 
toward  the  gum,  as  is  important  in  all  such  cases,  is  that  it  resists  the 
tendency  of  the  arch  to  slide  toward  the  occlusal  edges  of  the  teeth.  This 
tendencv  is  further  opposed  by  crossing  the  strands  of  the  ligature  near 
the  spur  during  the  adjustment  of  the  ligature. 

The  right  upper  central  is  also  encircled  by  a  ligature,  which  is  pre- 
vented from  sliding  off  the  tooth  by  the  hand. 

The  form  of  the  expansion  arch  was  occasionally  modified  by 
bending  to  meet  the  requirements  of  the  moving  teeth  and  prevent 
bunching. 

Owing  to  the  lingual  inclination  of  the  crowns  of  the  lower  incisors  no 
bands  on  them  were  necessary,  the  ligatures  simply  encircling  the  expan- 
sion arch  and  crowns  of  the  teeth.  It  will  be  noted  that  a  notch  in  the 
ribbed  arch  directed  the  movement  of  the  canine  laterally  as  well  as 
labially. 

The  slight  necessary  rotation  of  the  left  second  premolar  was  accom- 
plished by  bands,  spurs,  ligatures,  and  rubber  wedges,  as  already 
described,  as  soon  as  the  anterior  teeth  had  been  moved  into  correct 
position  to  reduce  the  crowding  and  permit  it  to  turn.  F'ig.  882,  made 
from  a  study  model  taken  in  wax  with  the  appliances  in  position,  shows 
the  movements  of  the  teeth  nearing  completion,  where  they  were  tem- 
porarily retained  pending  the  eruption  of  the  upper  canines. 

The  teeth  of  the  upper  arch  were  permanently  retained  in  their  new 
positions  by  a  section  of  wire  G,  soldered  to  the  mesio-lingual  angles 
of  bands  on  the  canines  and  made  to  bear  against  the  lingual  surfaces 
of  the  intervening  incisors,  as  in  Figs.  846  and  892. 

The  corrected  positions  of  the  lower  canines  and  incisors  were  main- 
tained also  by  a  similar  device. 

The  lesson  we  would  especially  impress  in  the  treatment  of  this  case 
of  malocclusion  is  the  important  one  of  growth  and  development  of  the 
alveolar  process  subsequent  to  the  movement  of  the  teeth  and  the  estab- 
lishment -of  normal  occlusion,  for  unless  nature  is  induced  to  complete 
the  growth  of  the  bone  which  has  so  long  been  arrested,  it  will  be  im- 
possible to  maintain  the  teeth  in  their  corrected  positions,  or  to  establish 
the  proper  contour  of  the  face.     In  this  case  we  were  fortunate,  for 


TREA  TMENT 


821 


after  two  years  of  retention  it  will  be  seen  hy  comparing  Fig.  .S83,  which 
shows  the  upper  model  of  the  case  soon  after  the  completion  of  tooth 
movement,  with  Fig.  884,  which  shows  the  ca.se  nearly  two  years  later, 
how  pronounced  and  gratifying  has  been  the  growth  and  development 
of  the  intermaxillary  bones  in  the  region  of  the  roots  of  the  incisors, 
and  the  shifting  of  the  very  apices  of  the  roots  of  these  teeth  as  well. 

Fig.  883^ 


Fig.  733  represents  the  face  of  the  patient  at  this  time,  and  the 
improvement  in  the  facial  contour  is  also  very  noticeable  and  gratifying. 
Let  the  reader  picture  in  his  mind  what  would  have  been  the  result  had 
extraction  been  resorted  to  in  the  treatment  of  this  case — a  practice 


Fig.  884 


still  insisted  upon  by  many.  The  function  of  occlusion  would  have  been 
greatly  impaired,  the  sizes  of  the  arches  diminished,  and  the  tongue 
restricted,  with  the  deformity  pronouncedly  manifest  in  the  irreparably 
impaired  facial  lines. 

In  the  case  represented  in  Figs.  885,  886,  887,  and  888  the  same 


822 


ORTHODONTIA 


(general  j)lan  of  treatment  and  retention  was  followed  as  in  the  last  case, 
and  the  verv  <;ratifvin<f  results  in  occlusion  and  hone  development,  and 


Fig.  SS5 


Fig.  886 


the  excellent  harmonv  in  lialance  of  the  facial  lines  of  the  patient  three 
years  later  are  shown  in  Figs.  889  and  890. 


TREATMENT 


823 


Had  the  workiiio;  retaiiuM'  \)vcu  employed  in  hoth  of  the  eases  last 
shown,  the  same  or  possibly  better  results  would  have  been  aceoiii- 
plished.  with  a  far  shorter  period  of  retention. 


Fig.  887 


Fig.  SSS 


824 


ORTHODONTIA 


Fig.  SOI  shows  a  case,  also  l)elonging  to  this  chiss,  in  whicli  there  is 
much  space  l)ctween  the  occlusal  edges  of  the  incisors,  the  result  of  the 
habit  of  holding  the  tongue  between   the  teeth.     The  cut  also  shows 


Fig.  889 


Fig.  890 


TREATMENT 


825 


the  method  of  correcting  the  infra-occlusion  of  the  incisors  hy  means  of 
the  expansion  arch.  The  niidclle  of  each  side  of  the  expansion  arch  was 
made  to  bear  against  a  spur  soldered  to  a  band  on  the  canine,  which 
acted  as  a  fulcrum,  the  centre  of  the  arch  being  sprung  over  hook-like 
spurs  projecting  from  the  labial  surfaces  of  bands  on  the  incisors,  and 
in  its  spring  thus  exerting  a  downward  force  upon  them.  Spurs,  in 
connection  with  the  bands  on  the  incisors,  for  engaging  the  expansion 
arch,  are  now  dispensed  with,  as  better  control  of  the  amount  of  force 
to  the  moving  teeth  can  be  gained  with  a  ligature  as  a  medium  of 
attachment,  the  bands  being  used  only  to  prevent  the  ligature  from 
slipping  oflf  the  tooth.  The  ligature  is  placed  about  the  neck  of  the  tooth 
and  given  one  twist,  the  arch  sprung  up  and  engaged  with  the  ligature, 
which  is  then  given  another  twist. 

Fig.  891 


^•HA. 


In  many  instances  the  bands  may  also  be  dispensed  with  by  placing 
a  ligature  about  the  neck  of  the  tooth  above  the  gingival  ridge,  twisting 
it  in  the  usual  way,  then  cutting  the  ends  off  short.  The  ligature  is 
then  conformed  still  more  closely  to  the  size  of  the  neck  of  the  tooth  by 
giving  it  a  final  set  or  part  of  a  twast  w^ith  the  How^  pliers.  Another 
or  independent  ligature  is  then  passed  between  the  neck  of  the  tooth 
and  the  first  ligature  and  made  to  engage  the  latter  and  the  expansion 
arch,  for  giving  the  downward  tension  upon  the  tooth.  Either  of  the 
arches  E  or  the  arch  B  may  be  used. 

In  correcting  infra-occlusion  of  the  teeth  by  this  excellent  method, 
it  has  been  found  that  the  spurs  acting  as  fulcrums  are  unnecessary,  the 
spring  of  the  arch  gained  through  the  pry  of  the  sheaths  of  the  anchor- 
bands  usually  being  ample.  It  is  well,  however,  to  reinforce  this 
anchorage  with  intermaxillary  anchorage;  that  is,  stretching  delicate 
rubber  ligatures  from  hooks  attached  to  the  upper  expansion  arch  to 
others  upon  the  lower  expansion  arch,  or  to  attachments  on  the  lower 
canines   as  in  Fig.  892. 

The  best  means  of  retaining  teeth  so  elevated  is  to  allow  the  expan- 
sion arch  to  remain  in  position  the  requisite  time. 

Fig.  893  shows  another  case  of  pronounced  infra-occlusion  of  the 


S26 


ORTHODONTIA 


incisors,  caniiics.  and  ])remolars,  principally  of  the  upper  arch.  This 
condition  was  augmented  hy  the  slight  su])ra-occlusion  of  the  second 
molars,  they  being  the  only  teeth  that  came  in  contact  when  the  jaws 
were  closed. 

Fig.  892 


The  plan  of  treatment  which  seemed  most  advisal)le  was  the  short- 
ening of  the  second  molars  and  the  lengthening  of  all  the  incisors  and 
canines.  This  was  accomjjlished  by  means  of  the  spring  of  the  expan- 
sion arches  reinforced  by  intermaxillary  anchorage,  exactly  as  described 
in  the  last  case. 

Fig.  893 


All  of  the  lower  incisors  and  canines  and  the  upper  lateral  incisors 
and  canines  were  banded  with  delicate  neatly  fitting  bands  made  from 
the  thinnest  band  material  (C).  These  bands  were  to  prevent  the 
ligatures  from  slipping  off  the  teeth.  This  was  necessary,  as  the  shapes 
of  these  teeth  were  not  favorable  for  retaining  the  ligatures  twisted  above 
their  gingival  ridges,  as  suggested  in  connection  with  the  case  last 
descril)ed,  l)ut  the  shapes  of  the  upper  centrals  being  favorable,  no 
bands  were  needed  on  them.  The  finest  of  the  three  sizes  of  wire 
ligatures  were  used  in  ligating  the  teeth  to  the  expansion  arches,  after 


TREATMENT  827 

the  latter  had  been  heiit  to  oi\(.  the  greatest  downward  spring  to  the 
upper  and  upward  spring  to  the  lower.  The  force  from  this  spring  was 
intensified  by  two  of  the  delicate  rubber  ligatures,  which  were  stretched 
from  one  arch  to  the  other  and  made  to  engage  spurs  which  had  been 
soft-soldered  to  the  expansion  arches  opposite  the  canine  teeth. 

It  will  be  noted  that  the  left  lower  first  molar  is  in  bucc-al  occlusion, 
and  that  its  antagonist  is  in  lingual  occlusion.  The  exj)ansion  arches, 
before  insertion,  were  bent  to  give  spring  for  the  correction  of  these 
positions. 

After  the  movement  of  the  teeth  had  been  continued  for  about  six 
months  a  period  of  rest  was  given  the  patient  to  await  the  growth  of 
the  alveolar  process,  during  which  time  retention  of  the  teeth  was 
effected  simply  by  allowing  the  arch  and  ligatures  to  remain  passively 

Fig.  894 


in  position.  The  case  was  of  course  occasionally  inspected  to  make 
sure  that  all  bands  and  ligatures  were  in  order,  and  at  the  end  of  the 
period  of  rest  the  development  of  the  tissues  was  noticeable  and  gratifying. 
The  expansion  arches  were  removed  and,  after  bending  them  to  give 
the  necessary  spring,  they  were  reinserted  and  tension  again  given  to 
the  teeth  through  the  adjustment  of  ligatures,  as  previously.  After 
continuing  the  movement  very  slowly  for  three  months  more,  an  impres- 
sion was  taken  of  the  labial  and  buccal  surfaces  of  the  teeth  while  in 
occlusion,  as  illustrated  in  Fig.  894,  which  truthfully  indicates  the  re- 
lations of  the  teeth  at  this  time. 

Further  movement  of  the  teeth  seemed  unnecessary.  The  patient 
was  again  dismissed  with  instructions  to  return  for  occasional  inspec- 
tion of  her  teeth,  which  were  retained  as  formerly  by  means  of  the  arch 


828  ORTIlODONriA 

and  ligatures.  These  were  worn  for  about  a  year  and  then  removed. 
No  unfavorable  movements  of  the  teeth  recurred. 

Great  caution  should  be  oi)serve(l  in  all  such  extensive  operations  for 
elevating  the  teeth  not  to  excite  inflammation  or  to  move  the  teeth  too 
rapidly.  The  movement  should  be  very  slow,  but  continuous,  otherwise 
there  will  be  great  danger  of  destroying  the  pulps.  This  should  be  ap- 
parent when  we  remember  how  extensive  must  be  the  changes  in  the 
peridental  membrane  and  alveolar  process,  and  what  a  severe  strain 
is  put  upon  these  tissues  incident  to  effecting  such  great  changes  in  the 
positions  of  the  teeth. 

Such  cases  present  many  points  of  interest,  especially  the  readiness 
and  completeness  with  which  the  gum  tissues,  and  probably  to  some 
extent  the  alveolar  tissues,  follow  the  teeth  in  these    extensive   move- 

FiG.  895 


ments.  It  is  doubtful  whether  the  treatment  of  these  cases  should 
ever  be  undertaken  after  maturity,  although  we  have  as  yet  nothing 
but  theory  to  suggest  fear  of  alveolar  disintegration  as  a  result  later 
in  life.  Another  is  that  a  surprisingly  large  percentage  of  cases  of  this 
type  show  the  effect  of  some  serious  systemic  disturbance  early  in  the 
development  of  the  enamel  of  the  incisors  and  first  molars,  strongly 
suggesting  the  closer  study  of  the  early  history  of  these  cases  if  we  would 
learn  their  cause. 

That  this  case  might  have  been  treated  more  satisfactorily  from  begin- 
ning to  end  by  means  of  the  working  retainer  device  showm  in  Figs.  858 
and  859. 

Fig.  895  shows  the  buccal  aspect  of  a  case  of  malocclusion  l^efore 
and  after  treatment,  the  cause  of  the  malocclusion  being  mutilation  by 


TREATMENT  829 

extraction.  The  occlusion  on  the  right  side  was  normal.  On  the  left 
(upper  model)  the  lateral  halves  of  both  arches  were  shortened,  the 
upper  permanent  lateral  incisor  being  in  contact  with  the  first  premolar. 
There  was  a  shrunken  appearance  of  the  mouth,  and  the  incisors  were 
shifted  from  the  median  line.  This  condition  was  the  result  of  the  un- 
fortunate and  unnecessary  loss  of  the  deciduous  upper  canine  and  the 
first  and  second  deciduous  lower  molars. 

It  needs  but  slight  reflection  to  realize  what  must  follow  as  the  result 
of  this  loss.  The  permanent  upper  canine  on  erupting  must  he  forced 
into  pronounced  labial  occlusion,  with  marked  disturbance  of  the  left 
lateral  and  central,  while  in  the  lower  jaw  marked  malocclusion  must 
follow  the  eruption  of  the  premolars. 

The  treatment  clearly  indicated  was  the  lengthening  of  the  left  lateral 
halves  of  both  arches  the  full  amount  of  the  missing  teeth  by  carrying 
forward  and  laterally  (to  the  right)  all  the  incisors. 

Fig.  896 


This  was  accomplished  in  both  arches  simultaneously  by  means  of 
expansion  arches,  bands,  and  ligatures.  No  bands  on  the  teeth  to  be 
moved  were  necessary.  The  incisors  were  laced  to  the  arch  with  plain 
ligatures,  as  in  A,  Fig.  807.  The  notches  in  the  ribbed  arches  for  pre- 
venting the  ligatures  on  the  upper  lateral  incisor  and  lower  canine  from 
slipping  were  placed  about  opposite  the  rniddle  of  the  centrals,  so  that 
force  produced  by  tightening  the  nuts  in  front  of  the  anchor  sheaths  on 
the  first  molars  exerted  a  direct  mesio-labial  movement  of  these  teeth, 
and  as  the  nuts  were  tightened  only  on  the  affected  side  the  lateral 
shifting  of  the  incisors,  as  the  arches  were  lengthened,  was  natural  and 
easy. 

The  result  of  treatment  is  shown  in  the  lower  model,  the  sides  of 
the  arches  having  been  sufficiently  lengthened  to  admit  of  the  eruption 
of  the  upper  canine  and  lower  premolars. 

Retention  of  the  space  for  the  premolars  in  the  lower  arch  was  effected 
by  means  of  the  device  shown  in  Fig.  837,  and  for  the  upper  canine  as 
shown  in  Fig.  838.     These  were  worn  until  the  eruption  of  the  teeth 


830  ORTHODONTIA 

made  their  use  no  longer  necessary.     This  is  a  very  desirable  nietiiod  of 
retention  in  all  similar  cases. 

On  the  right  of  the  engraving  (Fig.  89(5)  is  shown  the  model  of  a 
case  from  which  several  valuable  lessons  may  be  learned.  The  case 
was  that  of  a  girl,  aged  sixteen  years.  Two  years  previous  to  the 
making  of  this  model  the  occlusion  of  her  teeth  was  practically  fault- 
less, and,  with  the  exception  of  the  left  lower  first  molar  her  teeth  were 
of  excellent  structure  and  color.  At  this  time  this  molar  was  lost 
through  extraction.  Then  progressively  followed  the  perversion  of  the 
normal  forces: 

1.  The  tipping  forward  of  the  second  molar — the  inevitable  result. 

2.  The  shifting  distally  of  this  lateral  half  of  the  mandible. 

3.  Pressure  from  the  lower  lips,  which,  in  connection  with  the  shifting 
distally  of  the  mandible,  would  soon  move  into  complete  distal  occlusion 
the  teeth  in  this  lateral  half  of  the  lower  jaw  anterior  to  the  space. 

4.  Pressure  from  the  upper  lip  has  gradually  moulded  the  upper  arch 
to  conform  to  the  diminishing  size  of  the  lower,  as  shown  by  the  bunching 
of  the  upper  incisors. 

In  connection  with  this  case  attention  was  called  for  the  first  tmie  in 
literature  to  the  shifting  distally  of  the  mandible  as  one  of  the  results 
of  extraction  of  the  first  permanent  molar.^  It  should  be  explained 
that  this  must  result  as  the  fixed  relations  of  the  crown  through  the  in- 
clined occlusal  planes  with  those  of  the  opposing  teeth,  so  that  in  reality, 
instead  of  the  crown  of  the  lower  second  molar  tipping  forward,  as  it 
appears  to  do,  the  mandible  and  the  apices  of  the  root  of  this  tooth 
move  distally,  following  the  line  of  least  resistance.  Later  the  restrain- 
ing influence  of  the  occlusion  would  be  wholly  lost.  Then  the  actual 
tipping  forward  of  the  crown  of  the  tooth  will  occur,  as  in  Fig.  897. 

The  treatment  clearly  indicated  ^\as  the  lengthening  of  the  lateral 
half  of  the  lower  arch,  the  tipping  to  an  upright  position  of  the  second 
molar,  and  the  correction  of  the  positions  of  the  teeth  in  the  upper  arch, 
or  the  restoration  of  the  occlusal  planes  of  all  of  the  teeth  to  their  original 
positions,  as  is  shown  in  the  model  of  the  completed  case  on  the  left  of 
the  engraving  Fig.  896. 

The  patient  was  then  referred  to  her  dentist  for  an  artificial  substitute 
for  the  lost  molar,  which,  being  provided  in  the  form  of  a  bridge,  served 
the  double  purpose  of  retention  and  mastication.  The  requirements 
of  orthodontia  and  bridging  are  such  as  should  induce  a  closer  study  of 
their  relations,  and  if,  before  making  bridges  for  their  patients,  dentists 
would  refer  them  to  competent  orthodontists,  better  results  would  very 
often  follow.  The  placing  of  bridges  on  leaning  piers  is  unmechanical, 
and,  as  applied  to  the  mouth,  is  also  unphysiological. 

A  point  we  would  emphasize  in  relation  to  this  case  is  that  the  changes 

*  Angle,  Malocclusion  of  the  Teeth,  sixth  edition. 


TREATMENT 


831 


taking  place  in  this  previously  faultless  arch,  as  the  result  of  the  loss  of  the 
first  molar,  are  such  as  must  and  do  always  follow  the  loss  of  this  tooth. 
Examine  a  thousand  similar  cases,  and  as  many  similar  results  will  be 
found. 

It  will  be  noticed  that  in  the  model  on  the  right  none  of  the  teeth  on 
the  left  side  occlude,  but  that  they  merely  touch  at  irregular  intervals, 
and  are  practically  worthless  for  mastication.  What  we  would  especially 
emphasize  in  this  connection  is  that  the  lost  tooth  must  be  immediately 
replaced  by  some  form  of  artificial  substitute,  or  the  serious  impairment 
of  the  occlusion  of  the  remaining  teeth  on  the  side  of  the  arch  from 
which  the  tooth  has  been  extracted  will  certainly  follow. 


Fig.  897 


As  the  same  plan  of  treatment  was  employed  for  accomplishing  the 
various  necessary  tooth  movements  in  this  case  as  in  overcoming  the  same, 
but  more  complicated,  problems  in  the  case  next  to  be  shown,  they  will 
be  described  in  connection  with  that  case. 

Figs.  897  and  898  show  a  most  unfortunate  result  from  both  right  and 
left  sides,  following  the  extraction  of  the  four  first  permanent  molars, 
which,  though  perfectly  sound,  were  removed  at  the  age  of  nine  years, 
with  the  idea  of  making  space  to  prevent  malocclusion  of  the  other  teeth, 
and  how  successful  was  the  effort  is  readily  seen.  The  result  is  but 
natural.  Not  only  have  the  remaining  teeth  been  rendered  almost  useless 
for  mastication,  but  in  recent  years  there  has  been  chronic  pericementitis, 
resulting  from  the  wrongly  directed  force  upon  the  molars  in  their  tipped 
and  abnormal  positions.  The  facial  lines  were  also  greatly  marred  by 
the  arrest  in  the  development  of  the  alveolar  pTocess,  as  shown  on  the 
left  in  Fig.  741,  for  without  the  wedging  influence  of  those  most  important 


832 


ORTHODONTIA 


teeth — tlie  first  molars — tlie  teeth  anterior  could  not  be  pushed  forward 
by  the  eru})ti()n  of  the  second  and  third  molars,  which  is  necessary  for 
the  proper  contouring  of  the  face. 

Gold  capping  of  the  leaning  molars,  resorted  to  by  the  patient's 
dentist  in  this  case  to  improve  the  occlusion,  only  aggravated  the  condi- 
tion, for  the  gold  crowns  only  gave  a  longer  leverage,  thereby  increasing 
the  force  through  occlusion  for  the  further  tipping  of  the  teeth. 

There  was  but  one  logical  and  rational  plan  of  treatment,  namely, 
to  regain  the  lost  spaces  of  the  four  molars  by  carrying  all  the  teeth 
anterior  to  them  forward,  and  those  posterior  to  them  somewhat  distally 
and  to  an  upright  position,  and  replace  the  missing  teeth  by  artificial 
substitutes. 

Y\(:.  S98 


To  accomplish  this  all  four  second  molars  were  carefully  fitted  with 
D  bands,  the  sheaths  on  the  lower  bands  being  resoldered  to  align 
properly  with  the  expansion  arch.  The  ribbed  expansion  arches  were 
then  carefully  bent  to  conform  to  the  outside  of  the  dental  arches,  and 
were  inserted  without  lateral  spring  in  the  sheaths  of  the  clamp  bands, 
as  widening  the  dental  arches  was  not  necessary. 

The  central  and  lateral  incisors  of  the  upper  arch  were  then  ligated 
to  the  upper  expansion  arch,  the  simple  ligatures,  as  in  A,  P'ig.  807, 
being  employed,  and  in  like  manner  were  the  lower  incisors  attached 
to  the  lower  expansion  arch. 

Hook-like  notches  were  then  filed  in  the  ribs  of  the  expansion  arches 
directly  opposite  the  space  between  the  lateral  incisors  and  canines. 
Next  strands  of  the  heaviest  ligature  wire  were  looped  over  the  distal 
surfaces  of  the  second  premolars,  the  ends  brought  forward,  and  the  end 
of  each  lingual  strand  passed  through  between  the  canines  and  lateral 


TREATMENT  833 

incisors,  and  the  two  ends  of  each  strand  made  to  engage  their  n(;tch 
in  the  rib  of  the  expansion  arch,  just  described,  firmly  drawn,  and  given 
three-fourths  of  a  twist,  the  surj)his  wire  cut  oVi,  and  the  ends  l)ent  out 
of  the  way,  as  usual,  thereby  at  once  exerting  tension  in  a  mesial  direction 
on  all  the  second  premolars,  which,  in  turn,  was  transferred  to  the  first 
premolars  and  canines,  with  a  labial  movement  of  the  centrals  and 
laterals.  This  force  was,  of  course,  transmitted  in  the  opposite  direction 
to  the  second  molars,  and,  in  turn,  to  the  third  molars.  The  nuts 
of  the  expansion  arches  were  tightened  by  giving  them  one  revolution 
twice  a  week.  The  result  was  the  gradual  cai-rying  forward  of  all  the 
teeth  anterior  to  the  spaces,  and  at  the  same  time  the  movement  of  all 
the  molars  distally. 

The  most  difficult  problem  apprehended  was  to  gradually  effect  at 
the  same  time  the  tipping  to  an  upright  position  of  the  greatly  leaning 
lower  second  molars.  Yet  this  was  easily  accomplished  by  bending 
each  end  of  the  lower  expansion  arch  downward,  slightly,  at  a  point  just 
anterior  to  the  nuts  on  the  same,  so  that  when  the  arch  was  inserted  in 
the  sheaths  of  the  anchor  bands  and  the  anterior  part  of  the  arch  was 
drawn  up  and  ligated  to  the  incisors,  there  was  a  pry  upward  on  the 
mesial  ends  and  downward  on  the  distal  ends  of  the  sheaths  of  the 
lower  anchor  bands,  which  being  transmitted  through  the  tightly  clamped 
bands  to  the  teeth,  the  effect  was  to  rapidly  tip  the  molars  upward  and 
backward. 

As  the  movements  progressed,  the  spring  of  the  arch  from  the  upward 
pry  gradually  became  insufficient,  necessitating  the  removal  of  the 
lower  D  bands  and  the  resoldering  of  their  sheaths  in  order  to 
again  intensify  the  force  and  cause  the  further  tipping  distally  of  the 
molars. 

As  it  was  desired  to  carry  all  of  the  teeth  anterior  to  the  spaces  well 
forward,  the  force  necessary  was  so  great  that  before  the  movement 
of  these  teeth  was  completed  the  molars  had  been  carried  to  an  upright 
position  and  as  far  distally  as  was  necessary.  Their  further  movement 
was  then  arrested  by  so  bending  the  ends  of  the  arches  as  to  occasion 
their  binding  in  the  sheaths  and  prevent  further  tipping  distally  of  the 
molars,  or  changing  the  anchorage  from  simple  to  stationary. 

The  retention  in  this  case  now  would  be  to  allow  the  regulating  appli- 
ances to  remain  passively  upon  the  teeth  a  short  time,  replacing  them 
later  by  the  lingual  arch  retainer,  shown  in  Fig.  857,  and  finally  removing 
it  and  replacing  the  missing  molars  by  proper  bridges. 

Notwithstanding  the  advanced  age  of  the  patient  (thirty-eight  years), 
supposedly  unfavorable  for  the  treatment  of  malocclusion,  it  being  the 
most  advanced  age  recorded  for  such  an  extensive  operation,  the  writer 
was  agreeably  surprised  to  find  that  the  teeth  were  moved  quite  as  easily 
and  fully  as  rapidly  as  is  usual  in  the  case  of  a  miss  of  eighteen,  and  with 
no  unfavorable  symptoms  following  the  movement  of  any  of  the  teeth. 
63 


834 


ORTHODONTIA 


The  result  in  occlusion  is  showji  in  Fig.  S99.  It  will  he  seen  that 
all  of  the  teeth  anterior  to  the  space  have  been  carried  well  forward  and 
that  the  molars  have  been  moved  distally  and  into  correct  relations. 

The  remarkable  chanp;es  in  the  sizes  of  the  arches  and  in  the  relations 
and  inclinations  of  the  teeth  are  naturally  reflected  in  the  lines  of  the 
mouth  as  related  to  the  other  features,  as  will  be  noted  by  comparing  the 
face  after  treatment  (on  the  right  in  Fig.  741)  with  its  condition  before 
treatment  (on  the  left  in  Fig.  741 ).  Yet  great  as  are  the  changes  in  the 
facial  lines,  the  close  student  will  observe  that  there  is  still  not  complete 
normal  contour  of  the  mouth,  which,  as  we  perceive,  is  but  natural 
when  we  remember  how  the  arches  were  robbed  in  youth  of  that  normal 
wedging  influence  of  the  first  molars,  so  necessary  to  effect  the  normal 
development  of  the  bones  of  the  face  and  its  conse(|uent  normal  contour, 
which  could  not  be  wholly  regained  so  late  in  life. 

Fl.:.  899 


Another  point  of  great  interest  in  connection  with  this  case  is  the  posi- 
tive proof  that  even  in  this  remarkable  case  the  second  upper  molars 
had  not  moved  forward  farther  than  their  normal  positions,  notwith- 
standing the  early  loss  of  the  first  molars. 

Other  cases  belonging  to  this  class,  almost  innumerable,  might  be 
cited,  but  as  their  variations  from  the  cases  already  shown  would  be 
principally  in  degree,  with  the  same  general  plan  of  treatment,  it  is 
unnecessary  to  do  so. 

Treatment  of  Cases,  Class  II,  Division  1.— It  Mill  be  remembered 
that    the    distinguishing    characteristics    of    cases    belonging    to    this 


TREATMENT  835 

division  of  this  class  are  distal  occlusion  of  the  teeth  of  hotii  lateral 
halves  of  the  lower  arch,  with  more  or  less  deformed  and  underdevel- 
oped mandible,  narrowed  upper  arch,  and  protruding  upper  incisors. 
It  will  also  be  remembered  that  those  afflicted  with  this  type  of 
malocclusion  are  in  almost  every  instance  affected  with  some  form  of 
nasal  obstruction  necessitating  mouth  breathing,  which  usually  begins 
at  an  early  age,  causing  the  mouth  to  be  held  open  almost  constantly 
and  the  lips  and  buccal  muscles  to  act  abnormally.  In  the  eli'ort 
to  breathe,  the  upper  lip  is  drawn  upward  and  fails  to  develop  in 
size  and  function,  exercising  little  restraint  upon  the  labial  movement 
of  the  incisors.  Their  protrusion,  therefore,  becomes  more  and  more 
pronounced,  partially  as  a  result  of  pressure  from  the  tongue  and  narrow- 
ing of  the  arch  through  malocclusion  and  the  action  of  the  buccal  muscles, 
but  principally  because  the  lower  lip  is  so  frequently  forced  against  their 
lingual  surfaces  in  swallowing  and  in  the  effort  to  moisten  the  mucous 
membrane  of  the  mouth.  The  lower  incisors  become  lengthened,  prob- 
ably from  -lack  of  function,  so  that  their  occlusal  edges  are  in  many  cases 
in  contact  with  the  mucous  membrane  of  the  hard  palate. 

It  is  commonly  supposed  that  this  form  of  malocclusion  is  the  result 
of  overdevelopment  of  the  upper  jaw.  The  writer  has  never  seen  a  case 
where  this  condition  existed,  neither  are  the  teeth  of  the  upper  jaw 
"  inherited  too  far  forward,"  as  is  pointed  out  in  the  chapter  on  Occlusion. 

The  narrow^ed  upper  arch  and  protruding  upper  incisors,  the  lower 
jaw  abnormal  in  form  and  distal  in  relation,  the  arrest  in  the  develop- 
ment of  the  nasal  apparatus,  the  modification  in  form  and  function  of 
the  nose  and  muscles,  and  the  marred  facial  lines  are  but  the  natural 
results  of  the  failure  of  the  first  permanent  lower  molars  to  lock  normally 
at  the  time  of  their  eruption,  accompanied  and  probably  preceded  by 
pathological  conditions  of  the  nose  or  throat  that  established  the  habit 
of  mouth  breathing.  It  is  interesting  to  note  the  gradual  and  progressive 
development  of  cases  belonging  to  this  class — the  result  of  perverted 
forces  in  this  combination.  It  seems  reasonable  to  believe  that  the 
mandible  is  prevented  from  developing  normally  through  the  distal 
locking  of  the  teeth  and  the  consequent  abnormal  distribution  of  force 
from  the  muscles  and  the  force  of  occlusion.  Normally  the  force  is 
distributed  on  the  line  of  the  long  axes  of  the  teeth,  but  when  the  lower 
molars  lock  in  distal  occlusion  the  force  is  received  principally  upon 
the  anterior  half  of  their  crowns,  as  shown  in  Fig.  900,  the  tendency  being 
to  drive  their  apices  distally,  or  at  least  to  prevent  their  normal  move- 
ment forward,  which  would  also  prevent  the  normal  growth  and  lengthen- 
ing of  the  mandible.  This  seems  hitherto  to  have  been  unnoted,  yet  it 
seems  most  probable  when  we  consider  how  pronounced  is  the  interference 
with  the  normal  growth  of  the  mandible,  maxilla,  and  alveolar  process,  by 
the  abnormal  distribution  of  force  in  those  cases  where  the  upper  teeth 
on  erupting  lock  in  lingual  occlusion. 


836 


ORTIIODOXTIA 


Cases  })clono:iiio;  to  this  division  usually  begin  with  the  mal-locking  of 
the  first  i)ernianent  molars  at  the  time  of  their  eruption,  although  we  now 
know  that  they  may  be  established  much  earlier,  or  during  the  develop- 
ment of  the  deciduous  denture,  and  this  is  not  remarkable,  since  nasal 
obstructions  from  adenoid  growths  and  other  causes  are  often  well 
defined  at  two  and  three  years  of  age.  This  may  be  so  slight  at  first  as 
to  occasion  mouth  breathing  only  at  intervals  and  later  disappear  entirely, 
but  if  sufficient  at  the  time  of  the  eruption  and  locking  of  the  deciduous 
teeth,  or  of  the  first  permanent  molars,  to  decide  the  distal  locking  of  the 
cusps  of  the  teeth — and  but  a  few  days  would  be  necessary  to  accom- 
plish this — the  nucleus  of  conditions  would  be  established  which  must 
progress  until  all  of  the  conditions  of  a  typical  case  of  either  the  first  or 
second  divisions  of  this  class  have  developed.  Or,  if  the  distal  locking 
should  occur  only  on  one  side,  the  case  w'ould  belong  to  the  subdivision 
of  either  the  first  or  second  division. 


Once  established,  it  is  remarkable  what  similarity  exists  between  the 
cases  of  each  divi.sion,  especially  those  of  the  first,  the  diit'erences  being 
chiefly  in  degree,  which  is  usually  in  jjroportion  to  the  age  of  the  patient. 
And,  as  we  have  already  noted  in  the  section  on  Facial  Art,  the  disturb- 
ance in  the  balance  of  the  facial  lines  is  very  characteristic  and  in  direct 
proportion  to  the  degree  of  the  malocclusion. 

That  we  may  the  more  intelligently  decide  as  to  the  proper  plan  of 
treatment  in  these  cases,  there  is  another  (|uestion  which  is  well  worthy 
of  consideration,  and  it  is  the  inharmony  in  the  relations  of  the  opposing 
planes  of  the  teeth  in  their  distal  occlusion.  Apparently  this  is  not  great, 
judging  from  a  superficial  examination  of  the  buccal  relations  when  the 


TREATMENT 


837 


jaws  arc  dosed,  as  is  well  illiis(raU>(l  in  Fii>'.  900,  or  any  similar  case,  l)iit 
in  reality  it  is  very  great,  for  it  must  be  remeniberccl  that  each  occlusal 
plane  has  a  special  form  designed  by  nature  to  beautifully  match  and 
harmonize  with  its  natural  opposing  plane,  to  be  most  efficient  in  occlu- 
sion and  function,  as  we  have  seen  in  studying  the  normal.  But  with 
the  teeth  in  distal  occlusion,  each  inclined  plane  is  opposed  by  one  in- 
harmonious in  form  and  relation,  with  far  less  inefficiency  in  occlusion 
and  function.  This  is  better  shown  by  a  study  of  the  lingual  aspect  of 
this  same  case  shown  in  Fig.  901.  It  would  be  hard  to  estimate  how 
greatly  the  efficiency  of  the  molars  is  thus  impaired. 


Fig.  901 


The  writer  is  more  and  more  impressed  with  the  belief  that  this 
lessened  efficiency  and  perversion  of  the  occlusal  forces  has  much  to  do 
with  the  maldevelopment  of  the  mandible  in  these  cases. 

The  modern,  logical  plan  of  treatment  of  cases  belonging  to  this  division 
is  to  divert;  from  abnormal  to  normal  action  the  forces  which  are  oper- 
ative in  producing  the  deformity,  or,  first  to  remove  the  cause  by  proper 
treatment  of  the  nose,  making  normal  breathing  not  only  possible  but 
actual,  and  then  to  establish  the  proper  relations  of  the  occlusal  planes  of 
the  teeth — normal  occlusion — beginning  with  the  correction  of  the  mal- 
positions of  the  first  molars,  and  following  in  the  order  of  the  teeth 
mesially,  ending  with  the  incisors,  instead  of  beginning  with  the  protrud- 
ing upper  incisors,  the  symptoms,  as  it  were,  as  in  the  old  plan  of  treat- 
ment of  which  we  shall  speak  later.  Then  retaining  the  teeth  until  all 
of  the  tissues  and  muscles  involved  shall  have  become  normal  in  growth 


838 


ORTHODONTIA 


and  harnionious  in  function  through  their  mutual  cooperation.  Natu- 
rally the  earlier  the  treatment,  the  more  perfect  must  be  the  ultimate 
result. 


Fir..  902 


Fig.  903 


This  plan  of  treatment  i.s  illustrated  in  the  following  typical  average 
case — that  of  a  girl,  aged  thirteen  years.  The  case  is  shown  from  the 
buccal  aspect  of  the  right  and  left  sides  in  Figs.  902  and  903.     The 


TREATMENT 


839 


molars,  premolars,  and  canines  in  both  lateral  halves  of  the  lower  jaw- 
have  erupted  and  locked  in  distal  occlusion,  with  consequent  inharmony 
in  the  sizes  of  the  arclies  and  a  corresponding  inharmony  as  to  the  size 
of  the  mandible,  also  resulting  in  exactly  proportionate  disturbance  of 
the  beauty  and  balance  of  the  facial  lines,  as  shown  by  the  profile  in 
Fig.  904. 

To  establish  normal  occlusion  it  was  necessary  to  tip  the  crowns  of 
all  the  lower  teeth  forward  and  those  of  the  upper  arch  distally,  suffi- 
cient to  establish  the  normal  mesio-distal  relations  of  the  inclined  occlusal 
planes.  The  degree  to  whicii  the  teeth  of  each  arch  shall  be  moved 
varies  in  difi'erent  cases.  Usually  the  movement  should  be  about  equal 
in  each  arch,  for  reasons  to  be  noted  later. 


Fig.  904 


The  anchor  bands  D  were  carefully  fitted  to  all  four  first  molars, 
putting  the  bands  well  over  the  crowns,  with  the  tubes  aligned  correctly, 
and  the  screws  of  the  clamp  bands  lying  close  to  the  lingual  surfaces  of 
the  adjoining  teeth,  and  the  bands  finally  clamped  and  burnished  to 
complete  adaptation.  Plain  expansion  arches  were  now  carefully 
shaped  to  conform  approximately  to  the  sizes  of  the  dental  arches  and 
slipped  into  place,  the  upper  expansion  arch  aligning  a  little  below 
the  gingival  margin  of  the  incisors,  and  the  lower  expansion  arch 
aligned  about  the  middle  of  the  labial  surfaces  of  the  lower  incisors. 
Points  opposite  the  upper  lateral  incisors  were  now  indicated  on  the 
upper  expansion  arch,  the  arch  removed,  and  a  sheath-hook  attached 
at  each  of  the  two  points  indicated  by  means  of  a  very  small  piece  of 
soft  solder,  the  arch  carried  to  a  very  delicate  flame  and  the  temperature 


g40  ORTHODONTIA 

slowly  raised  to  the  fusing  point  of  the  solder,  jeweller's  soft  soldering 
fluid  being  used  as  a  flux.  When  gold  instead  of  nickel  silver  is  used 
for  the  arches  this  form  of  sheath-hook  is  not  used,  hut  hooks,  also  of 
gold,  are  soldered  directly  to  the  arch  with  22  k  gold  solder.  Soft  solder 
nnist  not  be  used  on  gold  nor  hard  solder  on  nickel  silver  arches. 

The  sheath  hooks  being  attached  to  the  arch,  it  is  again  inserted  in 
the  tubes  of  the  clamp  bands,  with  the  friction  sleeves  of  the  nuts  care- 
full  v  adjusted  in  the  extension  flange  of  the  anchor  tubes.  Much  care 
must  be  exercised  in  adjusting  the  bands  and  the  arches  so  that  the 
beautiful  fit  of  the  extension  flange  of  the  nut  with  the  friction  sleeve  of 
the  tube  of  the  clamp  band  will  not  be  injured. 

As  lateral  force  on  the  upper  molars  was  not  required  in  this  case,  they 
being  in  their  proper  lateral  as  well  as  mesio-distal  positions,  little  or  no 
outward  spring  was  given  to  the  expansion  arches.  Great  care  was 
exercised  to  bend  the  upper  expansion  arch  so  that  it  would  lie  close  to 
the  teeth,  yet  not  touch  any  of  them,  and  in  this  way  avoid  interference 
with  the  upper  lip  and  inconvenience  to  the  patient,  as  well  as  making 
the  appliance  less  unsightly. 

All  having  been  properly  adjusted,  one  of  the  delicate  rubber  ligatures 
was  caught  over  the  distal  end  of  the  sheath  of  the  anchor  tubes  on  the 
lower  molars  on  each  side,  stretched  forward  and  engaged  with  the 
sheath-hooks  on  the  upper  expansion  arch,  as  shown  in  Fig.  806,  at 
once  exerting  gentle  but  constant  force  distally  on  the  upper  molars  and 
mesially  on  the  lower  molars,  premolars,  and  canines. 

The  appliance  was  now  carefully  inspected,  to  be  certain  that  no  sharp 
corners  should  abrade  the  tissues,  and  especially  that  the  threaded  ends 
of  the  arches  did  not  protrude  distally  through  the  tubes,  these  ends 
having  been  cut  off  and  polished  when  the  arches  were  fitted.  Any 
exposed  portion  of  the  threads,  either  on  the  clamp  bands  or  expansion 
arches,  were  carefully  gone  over  with  a  burnisher.  The  patient  was 
directed  to  keep  the  mouth  closed  as  much  of  the  time  as  possible,  that 
the  force  exerted  by  the  rubber  ligatures  should  come  at  the  most 
favorable  angle  for  accomplishing  the  movement.  The  patient  was  then 
given  a  half  dozen  of  the  rubber  ligatures  and  instructed  as  to  how  to 
apply  them,  in  case  of  accident  to  those  already  in  position,  and  was 
then  dismissed  for  one  week. 

In  order  that  the  patient  might  be  caused  as  little  pain  and  incon- 
venience as  possible,  both  in  the  fitting  and  adjusting  of  the  appliances 
and  in  becoming  accustomed  to  wearing  them,  a  number  of  short  sittings, 
extending  over  a  period  of  at  least  two  weeks,  were  employed,  never  putting 
on  more  than  one  band  or  one  arch  at  a  time,  or  more  than  one  rubber 
ligature  on  a  side,  and  that  of  the  most  delicate  tension.  Later  two, 
or  even  three,  ligatures  may  be  worn  on  each  side  with  little  or  no  incon- 
venience. Thus  by  avoiding  pain  and  minimizing  the  inconvenience 
to  the  patient  in  the  beginning,  success  in  treatment  is  made  more  certain. 


J    • 


TREATMENT  841 

At  the  end  of  a  week  the  patient  returned,  and  it  was  found  that  the 
lower  teeth  had  tip])ed  sHiiihtl}'  forward,  as  evineed  by  the  anterior  part 
of  the  expansion  arch  ha^■ing  moved  perceptibly  downward  toward  the 
gingiva.  The  upper  niohirs  had  also  moved  slightly  distally,  as  evinced 
by  the  expansion  arch  resting  in  contact  with  the  labial  surface  of  the 
incisors,  as  well  as  moving  downward  toward  their  cutting  edges  to  a 
noticeable  degree  on  account  of  the  upper  molars  having  tipped  distally. 
The  nuts  in  front  of  the  anchor  tubes  on  the  upper  molars  were  now 
tightened  by  giving  them  one  and  one-half  revolutions.  Both  expansion 
arches  were  then  removed  and  the  upper  one  given  a  very  slight  upward 
bend  just  anterior  to  the  nuts,  so  that  it  would  align  correctly.  The 
arch  must  never  be  bent  but  very  slightly.  It  is  better  to  secure  align- 
ment by  readjusting  the  anchor  bands,  or  even  by  changing  the  angle 
of  the  anchor  tubes  by  resoldering,  although  the  latter  is  rarely  necessary. 

The  teeth  and  arches  w^ere  then  thoroughly  cleansed,  the  latter  slipped 
back  into  place,  fresh  rubber  ligatures  adjusted,  and  the  patient  instructed 
and  encouraged  in  the  proper  cleansing  of  the  teeth  and  dismissed  for 
another  week,  when  the  nuts  on  the  upper  ex-pansion  arch  were  again 
tightened  to  avoid  any  pressure  on  the  anterior  teeth  and  to  continue 
to  concentrate  it  all  on  the  molars. 

This  treatment  w^as  continued  until  the  upper  and  lower  molars 
were  in  complete  normal  mesio-distal  relations.  Indeed,  the  movement 
was  continued  until  the  molars  were  carried  a  little  beyond  their  normal 
relations,  to  allow  for  the  unavoidable  slight  recurrent  movement  of 
these  teeth  during  retention. 

The  upper  arch  and  anchor  bands  w^ere  then  removed  and  the  teeth 
thoroughly  cleansed.  X  bands  were  adjusted  to  the  second  premolars, 
the  nuts  turned  well  forward  on  the  expansion  arch,  the  tubes  aligned 
properly,  and  the  same  expansion  arch  again  inserted,  with  the  nuts 
again  so  adjusted  with  the  tubes  on  the  X  bands  as  to  prevent  any  pressure 
on  the  anterior  teeth.  Then  force  from  the  intermaxillarv  rubber  liga- 
tures  was  again  applied.  To  insure  the  distal  movement  of  the  first 
premolars  at  the  same  time,  they  w^ere  ligated  to  the  second  premolars. 
In  about  two  weeks  the  first  and  second  upper  premolars  on  both  sides 
had  been  moved  sufficiently  distally.  The  canines  had  also  been  moved 
somewhat  distally  through  their  relations  with  the  tissues  of  the  alveolar 
process  and  peridental  membrane. 

The  nuts  on  the  upper  expansion  arch  were  then  turned  well  back,  to 
release  the  force  distally  on  the  molars  and  premolars,  and  to  allow  all 
the  force  now  to  be  received  by  the  upper  incisors  and  canines.  About 
three  weeks  was  required  to  accomplish  their  necessary  distal  move- 
ment. 

As  the  same  amount  of  force  had  been  received  on  the  lower  as  on  the 
upper  teeth,  the  extent  of  the  movement  of  each  was  about  the  same,  and 
all  were  now^  in  normal  occlusion. 


842 


ORTHODONTIA 


There  was  found  to  l)e  some  slight  malalignment  of  the  lower  incisors 
at  this  time,  which  was  corrected  by  means    of    the    expansion    arch 


V\i..  905 


already  in  position,  plain  spurred  bands,  and  wire  ligatures,  the  same 
as  if  the  case  had  belonged  to  Class  I. 

The  teeth  were  retained  temporarily  in  their  new  relations  by  the  appli- 
ances already  in  position,  using  only  the  most  delicate  force  from  a 
single  rubber  ligature  on  each  side  and  stretching  this  only  one-half 


Fig.  906 


the  distance  from  the  tube  to  the  hook,  the  remaining  distance  being 
pieced  out  by  a  strand  of  floss  silk. 


TREATMENT 


843 


After  about  three  weeks  of  temporary  retention  the  apphances  were 
all  removed,  the  teeth  again  thoroughly  cleansed,  impressions  taken,  and 
models  of  the  teeth  made,  which  are  shown  in  Figs.  905  and  906. 

The  retention  of  the  molars  was  effected  by  adjusting  a  No.  2  clamp 
band  to  each  of  the  molars,  the  bands  fitted  with  planes  and  spurs  as 
described  for  the  retention  of  Class  II  cases  in  the  section  on  Retention. 

The  upper  incisors  were  retained  by  means  of  the  lingual  arch  shown 
in  Fig.  857,  its  ends  being  soldered  to  the  ends  of  the  screws  of  the  clamp 
bands,  and  the  incisors  held  in  proper  relation  with  the  arch  by  brass 
wire  ligatures,  as  described  in  the  section  on  Retention  for  cases  belonging 
to  this  class. 


Fig.  907 


The  lower  incisors  w^ere  retained  by  plain  bands  of  precious  metal 
on  the  canines,  connected  lingually  by  a  section  of  wire,  G,  as  in  Fig.  846. 

A  second  profile  photograph  of  the  patient  was  now  taken,  shown  in 
Fig.  907,  and  although  there  is  much  improvement  in  the  facial  lines, 
complete  normal  contour  of  the  face  is  still  lacking,  as  is  easily  under- 
stood when  it  is  remembered  that  we  have  corrected  the  occlusion  of  the 
teeth  only.  There  still  remains  the  underdeveloped  and  malformed 
mandible.  And  again,  the  muscles  had  been  abnormal  in  development 
and  function,  and  many  months  must  elapse  before  they  will  become 
harmonious  with  the  teeth  in  their  new  relations.  Indeed,  the  relations 
of  the  muscles  cannot  be  entirely  normal  until  the  mandible  has  under- 
gone much  modification  in  growth  and  development.  But  as  the  forces 
through  occlusion  have  been  changed  from  the  abnormal  to  the  normal, 
as  well  as  those  of  the  muscles  of  tongue  and  lips,  the  normal  in  the 
growth  has  been  made  possible,  and  nature  is  stimulated  to  complete 


844 


ORTHODONTIA 


the  (leiitiil  apparatus  normally,  or  in  atrordaiicc  with  her  orioinal  dcsiji^n 
of  the  ty|)e  of  this  child.  And  that  nature  wih  do  so  in  these  cases 
and  has  done  so  in  this  case  is  shown  hy  tiie  picture  of  the  patient 
three  years  hiter,  in  Fig.  90S,  and  it  is  phiin  to  he  seen  that  the  niandi- 
hle  has  developed  to  normal  proportions,  with  correspondingly  gratifying 
results  in  the  balance  of  the  face. 

This  case  also  has  an  historical  interest,  for  it  is  the  first  case  of  the 
kind  where  the  history  was  carefully  followed  and  reported  in  proof 
of  the  subsequent  development  of  the  mandible. 

Fig.  908 


In  establishing  the  normal  mesio-distal  relations  of  the  teeth  in  this  case, 
and  in  all  similar  cases,  the  (piestion  which  would  naturally  be  asked  is, 
Why  was  it  necessary  to  move  the  molars  and  premolars  of  the  upper 
arch  distally  if  they  were  already,  especially  the  first  upper  molars,  in 
their  normal  mesio-distal  positions  and  relations  with  the  skull  ?  The 
answer  is  very  simple,  namely,  that  we  might  the  more  easily  and  quickly 
and  safely  establish  the  normal  in  relation  of  the  inclined  occlusal  planes 
of  the  teeth,  and  the  better  stimulate  the  normal  in  the  growth  of  bone. 
Another  reason  is  that  if  all  of  the  movement  had  been  confined  to  the 
lower  teeth,  they  would  have  l)een  tipped  to  an  unsafe  angle  of  inclina- 
tion, but  by  striking  a  balance  between  the  teeth  of  the  two  arches  this 
is  avoided. 


TREATMENT 


845 


Of  course,  in  proportion  as  the  upper  teeth  are  moved  distally  to  the 
true  Hne  of  occlusion,  the  eifect  is  to  disturb  the  balance  of  the  face  so 
far  as  the  upper  dental  arch  is  concerned,  and  this  is  often  seen  in  these 
cases  after  following  this  plan  of  treatment;  but  it  must  be  remembered 
that  the  movement  of  the  upper  teeth  distally  and  the  consequent  dis- 
turbance of  balance  of  the  facial  lines  is  but  temporary.  The  changes 
in  development  subsequent  to  tooth  movement  must  and  do  gradually 
carry  the  upper  teeth  forward  again,  and  thus  through  the  influence  of 
the  inclined  planes  constantly  stimulated  to  greater  activity  and  better 
final  development  of  the  mandible,  for  it  cannot  be  too  often  repeated  that 
intelligent  efforts  in  orthodontia  can  never  be  more  than  to  assist  nature 
in  the  normal  building  of  the  denture  according  to  the  type. 


Fig.  909 


In  the  treatment  of  these  cases,  if  there  is  pronounced  arrest  in  the 
development  of  the  mandible,  it  may  be  found  that  the  lower  teeth  already 
incline  forward  to  such  an  extent  that  to  tip  them  still  farther  forward, 
equal  to  one-half  of  their  distal  relations  with  the  upper  teeth,  as  was 
done  in  the  treatment  of  the  case  last  described,  would  result  in  placing 
them  at  such  an  unsafe  angle  of  inclination  as  to  possibly  interfere  with 
the  subsequent  development  of  the  alveolar  process.  Such  a  case  is 
shown  in  Fig.  909.  It  is  then  advisable  that  the  movement  shall  be 
greatest  in  the  upper  teeth,  and  to  prevent  the  lower  teeth  from  moving 
too  far  forward  they  must  be  arrested  in  this  movement  at  the  proper 
time.  This  is  easily  accomplished  by  enlisting  stationary  anchorage 
between  the  lower  teeth  and  the  lower  expansion  arch  by  so  placing  the 
clamp-bands  on  the  lower  molars  that  the  tubes  will  cause  the  expansion 
arch  to  line  well  down  below  the  gingiva  in  front,  then  by  springing  it 
up  and  lacing  it  to  the  lower  incisors  l)y  means  of  wire  ligatures,  an 
upward  and  backward  pry  will  be  given  to  the  molars  by  the  elasticity 
of  the  arch,  which  will  prevent  further  tipping  and  mesial  movement  of 


846 


ORTHODONTIA 


the  lower  teeth,  and  all  of  the  movement  will  he  ^iven  to  the  upper  teeth. 
In  like  manner  the  movement  of  the  upper  teeth  may  be  arrested  when 
this  is  desired. 

Fic;.  910 


Fig.  910  shows  the  upper  arch  of  this  case  at  the  completion  of  the 
distal  movement  of  the  molars  and  premolars,  or  at  the  time  the  force 
was  released  from  the  molars,  by  turning  the  nuts  forward  and  trans- 
ferred to  the  upper  incisors.      It  is  in  such  cases  as  this  that  auxiliary 


Fig.  911 


force  from  occipital  anchorage  by  means  of  the  headgear  and  traction 
bar  may  with  advantage  be  used  to  assist  the  intermaxillary  ligatures  in 
carrying  the  upper  teeth  distally,  yet  this  necessity  would  be  very  rare, 
provided  the  movements  of  the  teeth  and  the  intermaxillary  anchorage 


TREATMENT 


847 
The  C()ii)i)leted  case 


were  carefully  watched  and  intelligently  managed 
is  shown  in  Figs.  911  and  912. 

Figs,  913  and  914  show  the  occlusion  of  the  teeth  in  a  well-defined 
case  belonging  to  this  division  of  a  child,  aged  less  than  four  years. 


Fio.  912 


It  will  be  seen  that  all  the  lower  teeth  are  in  distal  occlusion  and  all  of 
the  forces  wrongly  directed,  and  that  the  malocclusion  must  be  con- 
tinuously progressive  so  long  as  these  conditions  are  permitted  to  exist. 
Notwithstanding  the  complexity  of  the  malocclusion  and  the  extreme 
youth  of  the  patient  the  treatment  was  easily  and  successfully  performed 


Fig.  913 


by  the  plan  described  for  thp  treatment  of  the  case  shown  in  Figs.  902 
and  903,  and  Figs.  915  and  916  show  the  splendid  results  in  the  estab- 
lishment of  normal  occlusion. 

By  comparing  Fig.  917  with  Fig.  918  it  will  also  be  noted  how  marvel- 


848 


ORTIIODOXTIA 


Fig.  914 


Fig.  915 


Fig.  916 


TREATMENT 


849 


Fig.  917 

P^ 

|H|p       '\           ^, 

^4 

::^ 

% 

Si 

Fig.  918 


64 


850  ORTHODONTIA 

lous  are  the  changes  in  the  facial  lines  of  this  child  as  a  result  of  this 
treatment.^ 

As  the  result  of  intelligent  treatment,  nature  is  now  permitted  to  pro- 
gress normally  in  her  work  of  building  the  denture,  and  normally  erupting 
and  locking  the  first  permanent  molars,  and  the  prosj)ects  of  the  ideally 
normal  result,  as  compared  with  the  possible  result  in  cases  that  have 
been  allowed  to  progress  until  "all  of  the  teeth  (permanent)  have 
erupted,"  ought  strongly  to  impress  all  thoughtful  persons  with  the 
gravity  of  the  error  of  delay. 

Formerlv  two  other  methods  were  employed  in  the  treatment  of 
cases  belonging  to  this  division  of  this  class.  The  one  almost  universally 
followed  was  to  extract  the  first  upper  premolars  and  carry  the  incisors 
and  canines  distally  by  means  of  occipital  force  to  close  the  spaces. 
By  this  method  the  patching  up  of  one  deformity  by  creating  another 
often  left  the  malocclusion  worse  than  at  the  beginning  of  treatment, 
often  added  to  the  deformity  of  the  face,  and  made  further  improvement 
and  development  hopelessly  impossible.  The  method  is  so  crude,  illogical, 
and  unscientific  from  every  standpoint  that  it  has  been  completely 
abandoned  by  all  true  orthodontists. 

The  other  plan  formerly  employed  was  far  more  ideal.  It  was  given 
us  by  that  talented  man.  Dr.  5sorman  "W.  Kingsley,  and  was  known  as 
"jumping  the  bite."  It  consisted  in  the  patient's  moving  the  mandible 
forward  voluntarily  until  the  teeth  were  in  normal  mesio-distal  relations, 
the  width  and  form  of  the  upper  dental  arch  having  been  so  modified 
by  previous  corrective  measures  as  to  make  this  possible.  The  mandible 
was  then  forced  to  always  close  in  this  forward  position  by  means  of 
"bite  plates"  of  various  forms,  until  finally  it  became  so  modified  in 
form  and  in  relation  to  the  temporomaxillary  articulation  that  it  w^ould 
no  longer  move  distally,  as  before.  Notwithstanding  that  the  result  in 
occlusion  and  facial  balance  was  very  ideal,  the  difficulty  of  keeping 
the  mandiiile  in  the  forward  position  was  so  great  as  to  cause  some  to 
doubt  its  even  being  a  possil)ility.  Yet  that  it  was  accomplished  in  some 
favorable  cases  after  most  prolonged  and  difficult  retention  is  well 
known.  In  reality  we  now  accomplish  in  a  far  cjuicker  and  easier  manner 
the  same  ideal  results  by  means  of  the  intermaxillary  force  as  previou.sly 
described. 

As  previously  stated  there  were  formerly  much  in  vogue  two  other 
plans  for  establishing  harmony  in  the  sizes  of  the  dental  arches  in 
cases  belonging  to  this  division  of  this  class.  The  first,  and  one  which 
has  been  longest  practised,  necessitated  the  sacrifice  of  two  upper  pre- 
molars, usuallv  the  first,  followed  by  the  retraction  of  the  canines  and 
incisors,  in  order  to  harmonize  the  sizes  of  the  dental  arches,  and  many 

1  This  patient  was  treated  in  1904  by  Dr.  Guilhermena  P.  Mendell.  of  Minne- 
apolis. "When  first  reported  it  was  the  youngest  case  on  record  in  which  anything 
like  such  extensive  malocclusion  of  the  deciduous  teeth  had  been  corrected. 


TREATMENT 


851 


are  the  devices  which  have  been  employed  for  this  purpose.  Some  of 
them  are  extremely  crude  and  defective,  especially  in  the  principles  of 
anchorage,  usually  relying  upon  the  stability  of  the  first  molars  for 
overcoming  the  resistance  of  the  teeth  to  be  moved,  the  result  in  nearly 
every  instance  being  the  displacement  mesially  of  the  anchor  teeth, 
usually  more  than  the  anterior  teeth  were  moved  distally. 


e.H.A 


Fir,.  920 


Other  devices  depended  on  a  combination  of  molar  and  occipital 
anchorage,  with  better  results.  The  writer's  appliances  for  accomplish- 
ing the  retraction  of  the  incisors  and  canines  are  shown  in  Figs.  775 
and  919.  It  will  be  seen  that  stationary  anchorage  of  the  molars  is 
combined  with  occipital  anchorage,  making  use  of  the 
traction-screws,  as  in  Fig.  801,  in  combination  with 
the  arch  B,  the  distal  ends  of  the  arch  being  inserted 
in  short  sheaths  attached  to  the  long  sheaths  of  the 
traction  screw.  The  anterior  part  of  the  arch  B  is 
kept  in  contact  with  the  labial  surfaces  of  the  incisors 
(upper)  by  being  made  to  rest  in  notches  formed  in 
the  united  ends  of  plain  bands  on  these  teeth,  made 
from  the  band  material  F,  as  shown  in  C,  Fig.  920. 

Force  derived  from  the  headgear  through  heavy 
elastic  bands  is  transmitted  to  the  ball-and-socket 
joint  between  the  traction  bar  and  the  arch  B,  to  the  centre  of  the  arch 
B.  Additional  force  from  intermaxillary  anchorage  may  also  be  enlisted 
by  use  of  the  rubber  ligatures  made  to  engage  sheath-hooks  on  the  arch 
B  and  the  anchor-bands  on  the  lower  molars,  as  already  described  in  the 
first  plan  of  treatment.  Although  the  device  here  shown  is  unques- 
tionably the   most  simple   and  efficient  for  carrying  out  this  plan  of 


852 


ORTHODONTIA 


treatment,  yet  tlie  principle  of  treatment  itself  is  obviously  wr()ji<r  and 
ought  rarely,  if  ever,  to  be  employed,  for  at  best  it  is  only  palliative, 


Fk;.  921 


^^  ''^  liilBUllill  In  II  :iiiiiMJiiMiiw;:,.,,ijji 


Fig.   922 


creating  one  deformity  to  patch  up  another.     There  is  always  a  strained 
and  unnatural  look  given  to  the  mouth,  following  this  plan  of  treatment. 


TREATMENT  853 

The  writer  lias  yet  to  see  a  single  instance  where  the  facial  lines  have 
been  much  improved  over  their  former  condition,  and  in  some  instances 
they  had  been  made  radically  worse  after  treatment  by  this  method. 
Fig.  742  shows  the  facial  lines  of  one  patient  after  such  treatment. 

This  plan  of  treatment  was,  of  course,  excusable  before  the  intro- 
duction of  the  Baker  anchorage;  in  fact,  it  was  then  the  only  one  that 
might  safely  be  relied  upon ;  but  with  the  progressive  orthodontist  it  can 
no  longer  be  in  favor,  and  we  believe  it  is  destined  to  become  obsolete. 

Another  plan  of  treatment,  introduced  by  Dr.  Norman  W.  Kingsley, 
consisted  in  what  he  termed  "jumping  the  bite,"  or  shifting  the  position 
of  the  mandible  and  lower  teeth  from  distal  to  normal  occlusion  (which 
anyone  with  distal  occlusion  can  do  voluntarily),  and  holding  the  jaw 
in  this  position  by  some  form  of  mechanical  device  until  either  the  jaw 
or  temporomaxillary  articulation,  or  both,  had  supposedly  been  modified 
to  be  in  harmony  with  the  teeth  in  their  corrected  occlusion  or  normal 
relations,  when,  it  was  supposed,  there  would  be  no  recurrence  of  the 
former  condition. 

Fig.  923 


In  order  to  establish  harmony  in  the  occlusal  inclined  planes  in  this 
manner  it  was,  of  course,  necessary  to  first  place  the  teeth  of  the  upper 
arch  in  harmony  with  their  normal  line  of  occlusion;  that  is,  widening 
this  arch  somewhat  in  the  region  of  the  canines  and  premolars,  and 
moving  lingually  the  protruding  incisors,  which  was  done  by  various 
forms  of  mechanical  devices. 

This  plan  of  treatment  has  occasioned  much  controversy,  its  practi- 
cability being  doubted  by  many  and  stoutly  defended  by  others.  The 
great  advantage  of  the  method,  were  it  practicable,  over  the  one  last 
described  must  be  apparent  to  all,  for,  in  addition  to  the  first  requisite 
in  the  treatment  of  malocclusion,  the  complete  restoration  to  normal 
occlusion,  it  made  possible  the  restoration  of  the  chin  and  lower  jaw  to 


854 


OHTIIODONTIA 


hariiiony  of  l);ilaiic('  with  tlu'  rest  of  the  face.     Xo  wonder  it  .should 
liaw  stront;'  advocatos,  tvspecially  l)y  those  of  Dr.  Kingsley'.s  type,  who 


Fio.  924 


set  much  score  hv  the  artistic  l)alance  of  the  face.  But,  as  we  .shall  see, 
one  important  pha.se  of  the  conditions  contingent  on  this  plan  of  treat- 
ment has  been  overlooked  by  the  advocates  of  this  plan.  The  follow- 
ing ca.se,  which  was  treated  after  this  plan,  will  illustrate  t'liis.    The  ca.se 


Fio.  925 


was   that  of   a  boy  aged   nine  years.       It  will  be  seen  from  the  mal- 
occlusion (Fig.  921)  and  the  facial  lines  (Fig.  922)  diat  the  ca.se  is  one 


TREAT  MEW 


855 


tyj)ic'al  of  this  division  of  this  class.  The  first  ponnanent  molars  on 
botli  sides  liad  erupted  and  locked  in  complete  distal  occlusion,  with 
the  usual  narrowed  upper  arch  and  protruding  upper  incisors. 


Fii;.   9l'6 


Fig.  923  shows  the  occlusal  aspect  of  the  upper  arch,  and  the  dotted 
line  in  the  engraving  indicates  the  relation  of  the  lower  teeth. 


Fig.  927 


The  teeth  of  the  upper  arch  were  moved  into  correct  relation  with 
their  proper  line  of  occlusion,  which  resulted  in  the  shortening  and 


856  ORTHODONTIA 

widening  of  the  arch.  The  lower  jaw  oouUl  then  be  moved  forward, 
and,  upon  dosing,  the  teetli  were  in  normal  occlusion,  as  shown  in  Fig. 
[VIA.  Closure  in  this  position  was  compelled  by  the  devices  shown  in  the 
engraving  and  already  described  in  retention. 

This  j)lan  of  retention  was  continued  for  a  period  of  two  years,  being 
shifted  from  one  side  to  the  other,  and  occasionally  employed  on  both 
sides  at  the  same  time.  It  will  be  noted  by  studying  the  profile  of  the 
young  man's  face  (Fig.  925)  that  the  lower  jaw  has  been  carried  well  for- 
ward, and  that  it  is  now  in  excellent  harmony  with  the  rest  of  the  face, 
in  marked  contrast  with  the  weak,  receding  chin  shown  in  Fig,  922. 

Gradually  retention  was  discontinued,  and  the  deciduous  molars  were 
lost  and  replaced  by  their  successors,  each  locking  normally  with  its 
antagonist.  Some  two  years  after  all  devices  for  mechanical  retention 
had  been  removed,  a  study  of  the  occlusion  of  the  teeth,  as  shown  in  the 
correctly  made  models  (Fig.  926),  revealed  normal  occlusion.  The  writer 
felt  positive  he  had  succeeded  in  "jumping  the  bite."  Meantime' other 
cases  had  been  carried  on  with  equally  good  results.  But  an  important 
change  had  been  taking  place  in  this  case,  probably  from  the  very  begin- 
ning of  retention,  and  yei  unnoticed.  This  change  was  discovered  by 
a  comparison  of  the  profile  of  the  young  man  at  the  age  of  fifteen  (Fig. 
927)  with  the  photograph  of  his  profile  taken  at  the  time  of  completion  of 
treatment  (Fig.  925).  It  clearly  showed  that  instead  of  the  temporo- 
maxillary  articulation  having  been  permanendy  modified  to  be  in  har- 
mony with  the  new  position  of  the  mandible,  that  in  reality  the  mandible 
had  gradually  worked  back  into  its  old  relations,  and  that,  too,  without 
displacing  the  normal  relations  of  the  inclined  occlusal  planes,  the  expla- 
nation of  this  being  that  the  crowns  of  the  upper  teeth  had  to  a  certain 
extent  been  tipped  distally  and  the  crowns  of  the  lower  teeth  more  or  less 
mesially;  or,  in  other  words,  there  had  occurred  in  this  two-year  period 
of  retention  what  we  now  aim  to  accomplish  and  do  accomplish  in  a  very 
few  weeks  with  the  Baker  anchorage. 

Inspection  of  other  cases  showed  like  results.  In  one  instance  in  which 
retention  had  been  continuous  on  one  side  the  same  result  had  occurred, 
as  shown  in  Fig.  926,  but  on  the  other  side,  the  retaining  device  having 
been  lost  and  not  replaced,  as  the  mandible  regained  its  former  relations, 
the  teeth  also  drifted  back  into  their  original  positions  of  distal  occlusion. 

Class  II. — Division  1,  Subdivision. — Practically  the  same  conditions 
are  met  in  cases  belonging  to  the  subdivision  of  Division  1,  Class  II,  as 
are  found  in  Division  1,  just  described,  the  only  difference  being  that 
on  one  side  only  have  the  teeth  locked  abnormally,  or  the  lower  in  distal 
occlusion,  the  teeth  on  the  other  side  being  locked  in  normal  occlusion. 

There  is  the  same  narrowing,  only  less  in  degree,  of  the  upper  arch, 
with  incisors  protruding,  in  many  instances  quite  as  much  as  in  the  full 
division,  and  with  facial  lines  marred  just  in  proportion  to  the  extent  of 
the  malocclusion. 


TREATMENT  857 

The  treatment  indicated  is  the  same  as  in  all  cases  of  malocclusion, 
namely,  the  estahlishineut  of  the  normal  relations  between  the  inclined 
occlusal  planes.  In  this  class  of  cases  this  is  hrouf^ht  ahout  in  pre- 
cisely the  same  manner,  and  wiUi  the  same  combination  of  appliances 
used  in  the  same  way,  as  in  cases  belonging  to  the  full  division,  or  in 
distal  occlusion  on  both  sides,  except  that  the  sheath-hook  and  rubber 
ligatures  for  shifting  the  upper  teeth  distally  and  the  lower  teeth  mesially 
are  used  only  on  the  side  of  the  distal  occlusion,  although  sometimes, 
in  order  to  maintain  the  proper  balance  of  the  appliance,  only  gentle 
intermaxillary  force  becomes  necessary  as  well  on  the  normal  side. 

Of  course,  if  there  is  required,  and  there  often  is,  any  individual  tooth 
movement  in  either  of  the  dental  arches,  they  are  effected  at  the  same 
time  as  the  distal  shifting  of  the  upper  teeth  and  the  mesial  tipping  of 
the  lower  by  means  of  spurred  bands  and  wire  ligatures,  as  described 
in  the  treatment  of  cases  belonging  to  Class  I. 

The  teeth  that  have  been  moved  are  retained  in  the  same  way  as 
described  for  cases  belonging  to  Division  1,  Class  II. 

Fig.  928 


Class  II. — Division  2. — It  will  be  remembered  that  in  cases  of  mal- 
occlusion belonging  to  this  division  of  Class  II,  as  in  those  of  Division  1, 
the  teeth  of  the  lower  arch  are  in  distal  occlusion  in  both  its  lateral  halves. 
The  upper  arch,  unlike  that  in  cases  of  Division  1,  which  is  abnormally 
long  and  narrow,  is  shortened,  with  incisors  bunched  and  overlapping, 
as  in  Fig.  928,  to  approximately  harmonize  in  size  with  the  anterior  part 
of  the  lower  arch.  Unlike  the  conditions  of  Division  1,  the  lower  incisors 
are  not  elevated  in  their  sockets,  owing,  probably,  to  their  greater  use, 
and  there  is  normal  respiration  and  lip  function,  with  a  far  more  normal 
vault  and  width  of  arch,  but  the  result  of  distal  occlusion  and  recession 
of  the  jaw  and  chin  greatly  mars  the  facial  lines,  as  shown  in  the  face 
in  Fig.  736. 

The  logical  plan  of  treatment  in  this,  as  in  all  cases  of  all  classes, 
and  one  that  is  thoroughly  practical  and  not  difficult  of  accomplish- 


858 


ORrilODOXTIA 


mcnt,  especially  if  troiifineiit  he  hct^mi  cai'ly  and  intclliifontly  maiia^eil, 
is  tlu-  estal)lishinciit  of  iioniial  occlusion  of  the  ieetli. 

As  eases  heloii^iiii^  to  this  division  re(|uire  the  same  nioveinents  of 
the  molars,  premolars,  and  canines  as  do  cases  l)elon(i;in(j;  to  Division  1 
of  this  class,  they  are  accomplished  in  exactly  the  same  way  and  with 
the  same  combination  of  appliances. 

But  the  upj)er  incisors,  being  more  or  less  retruded,  bunched  and  over- 
lapping, their  torsal  and  labial  movements  are  recjuired,  and  these  are 
effected  at  the  same  time  the  up})er  molars  and  premolars  are  moved 
distallv,  by  means  of  plain  l)ands,  spurs,  and  ligatures  engaging  the 
expansion  arch,  precisely  as  would  be  done  in  cases  belonging  to  Class  I 
(see  Fig.  769),  the  mesial  movements  of  these  teeth  reciprocating  force 
to  the  molars  and  making  more  easy  the  movement  of  both. 


Fn;.  929 


If  the  positions  of  the  lower  incisors  require  corrections,  this  is  accom- 
plished bv  bands,  spurs,  and  wire  ligatures  in  connection  with  the  lower 
expansion  arch,  at  the  same  time  the  mesial  movement  of  the'  lower 
molars,  premolars,  and  canines  is  effected. 

Both  upper  and  lower  incisors  are  retained  in  the  same  manner  as 
for  the  same  teeth  in  (Mass  I,  similar  tooth  movements  having  been 
performed,  and  the  molars,  premolars,  and  canines  as  previously  de- 
.scribed  for  the  retention  of  these  teedi  in  Division  1,  Class  II. 

Although  these  cases  are  apparently  more  complicated  than  those  of 
the  first  division,  usually  they  are  more  easily  treated. 

Again,  as  the  patients  are  normal  breathers  and  keep  the  mouth 
closed  the  requisite  amount  of  time,  the  time  of  retention  of  the 
molars  by  mechanical  devices  is  shorter,  as  the  normal  locking  of 
the  cusps — nature's  most  important  retaining  device— thus  becomes 
more  effective. 

Fig.  929  shows  the  case  corrected  and  at  the  time  of  adjustment  of 
the  retaining  devices,  and  the  face  in  Fig.  737  shows  the  result  of 
treatment  on  the  facial  lines 


TUKATMEXT 


fi50 


'riu>  rwsv  \\vYv  shown  is  one  j)Ui'|)()S('ly  selected  as  l)ein<,^  not  only 
typical,  hut  also  of  nmisnai  (hfhculties,  owiiijj;  to  the  hir^e  size  and 
density  of  the  jaws,  and  tlie  full  eonipleuient  of  unusually  lar^'e  teeth, 
all  of  which  were  in  malocclusion  and  re(|uired  to  be  moved  in  order 


J'k;.   030 


to  carry  ont  this  plan  of  treatment,  yet  the  mesial  movements  of  all  the 
lower  teeth  and  the  opposite  movement  of  the  upper  molars,  premolars, 
and  canines,  together  with  the  necessary  individual  movements  of  the 
incisors  and  canines,  were  efi'ected  simultaneously  and  in  about  three 
months'  time. 

Fig.  931 


Of  course,  the  golden  time  for  the  treatment  of  this  case  was  at,  or 
soon  after,  the  time  of  the  eruption  of  the  first  molars,  and  the  difficul- 
ties of  treatment  have  gradually  increased  with  the  advance  of  years. 
It  is  quite  probable  that  all  that  would  have  been  necessary  at  that 


800 


oirrifoDOXTiA 


time  would  have  hecii  .simply  the  diirctin^  into  normal  relations  of  the 
first  molar  teeth. 

Fiif.  \YM)  shows  the  malocchisioii  of  another  case  from  both  riijfht 
and  left  sides,  this  patient  being  mueli  younger,  hut  the  treatment  being 
after  the  same  plan. 

Fig.  931  shows  the  facial  lines  of  the  patient  before  treatment  and 
how  greatly  they  were  marred  by  the  pronounced  malocclusion. 

Fig.  932  shows  the  case  at  the  time  of  the  adjustment  of  the  retain- 
ing devices,  and  it  will  be  noticed  how  short  the  bite  is  in  the  incisive 
region,  and  this  gives  us  an  opportunity  to  point  out  the  importance  of 
establishing  the  normal  length  of  overbite,  and  while  this  condition  may 
be  met  in  the  treatment  of  any  case  of  any  class,  it  is,  as  Dr.  Kirk  has  well 
said,  "of  quite  as  much  importance  that  the  proper  length  of  bite  be 
established  as  it  is  that  any  other  phase  of  malocclusion  be  corrected." 


Fic.  932 


Where  the  overbite  may  in  some  instances  be  due  to  the  supra-eruption 
of  the  incisors,  it  will  in  most  instances  be  found  to  be  due  to  the  infra- 
eruption  of  the  first  molars,  and  usually  the  lower  ones. 

Naturally  the  elevation  and  retention  of  the  lower  first  molars  by 
mechanical  means  would  seem  to  be  the  correct  solution  of  this  problem, 
and  while  their  elevation  is  not  difficult  to  accomplish,  yet  the  writer 
has  never  been  successful  in  maintaining  the  teeth  in  this  position,  even 
though  they  had  been  mechanically  retained  for  many  months,  for  upon 
the  removal  of  their  mechanical  support  they  would  gradually  settle 
back  into  their  original  positions  and  the  overbite  become  as  before. 
The  reason  for  this  was  puzzling,  yet  when  we  remember  the  great 
force  received  upon  these  teeth  from  occlusion  and  the  great  disturbance 
in  the  attachment  of  the  fibers  in  the  peridental  membrane,  and  especially 
the  immense  number  of  suspensory  fibers  which  have  been  recurved 
upon  themselves  in  the  elevation  of  these  teeth,  we  can  understand 
how  long  a  period  of  time  must  be  required  before  there  can  be  a  recon- 


TREATMENT 


861 


structed,  normally  functionating  membrane  and  osseous  attachments, 
especially  in  patients  nearing  maturity.  So  the  plan  that  the  writer 
has  found  to  be  most  satisfactory  is  one  that  has  long  been  in  use,  namely, 
to  separate  the  bite  by  a  vulcanite  plate,  thickened  in  front  and  covering 
the  vault  of  the  arch,  with  depressions  in  the  plate  for  the  reception  of 
the  lower  incisors  so  that  the  full  thrust  of  the  jaw  may  be  received  upon 
these  teeth  instead  of  upon  the  molars.  The  plate  is  prevented  from  being 
forced  upward  in  front,  and  from  being  loosened  in  the  rear,  by  hooks 
firmly  embedded  in  the  plate  and  made  to  engage  the  cutting  edges  of 
the  upper  incisors.  When  properly  adjusted  this  plate  should  relieve 
all  strain  from  the  opposing  first  molars  which  are  separated  at  least 
three  thirty-seconds  of  an  inch.    If  constantly  worn  for  from  six  months 


¥10.  933 

Fig.  934 

fikNI 

I 

to  a  year  the  molars  will  have  become  lengthened  and  the  proper  length 
of  bite  established.  The  result  of  this  method  of  treatment  is  shown  in 
the  fine  balance  that  has  been  given  to  the  facial  lines  (Figs.  933  and  934) 
and  in  the  improvement  in  the  occlusion  (Figs.  935  and  936). 

It  may  be  well  to  note  that  in  nearly  all  cases  belonging  to  Class 
II  there  is  more  or  less  of  an  abnormal  overbite,  sometimes  most  pro- 
nounced, but  it  is  gratifying  to  note  that  this  will  in  most  instances 
disappear  as  the  crowns  of  the  teeth  are  tipped  into  their  normal  posi- 
tions, or  their  normal  angles  of  inclination  established. 

While  numerous  simpler  cases  belonging  to  this  division  might  be 
reported  here,  this  seems  unnecessary,  as  the  stories  they  might  tell  in 
occlusion  and  art  and  in  the  methods  of  accomplishing  the  various 


cSGL' 


OHTIIODOXTIA 


tooth  uiovcmciits  arc  ('iiihraccd  in  the  cases  ulrcady  rcj)ortc(l,  and  if  these 
he  undcMstood  the  treatment  of  simple  cases  should  ofi'er  no  difficult 
prohlems. 

Fic.  OS.-) 


Fig.  936 


Class  II.— Division  2,  Subdivision.— In  cases  belonoin^  to  this  sub- 
division the  conditions  and  indications  for  treatment  on  the  abnormal 
side  are  similar  to  those  in  Division  2,  Class  II,  just  described,  the 
differences  bein^-,  like  those  of  the  subdivision  of  Division  1,  (Mass  II, 
that  one  of  the  lateral  halves  of  the  dental  arches  only  is  in  distal  occlusion, 
the  lower  first  molar  on  this  side  failing  to  lock  normallv;  but,  as  it 


TREATMENT 


863 


erupted,  was  sliifted  into  distal  occlusion,  necessitating  the  abnormal 
locking  of  each  succeeding  tooth  that  erupted  on  that  side,  until  we 
have  inharmony  in  the  sizes  of  the  arches,  the  upper  being  larger  to 
the  extent  of  one  premolar  tooth,  and  the  compensation  being  in  the 
overlapping  of  the  upper  incisors  and  canines,  as  shown  in  the  typical 
case,  P'ig.  987. 

Fig.  937 


The  treatment  clearly  indicated  was  the  correction  of  the  malposi- 
tion of  each  tooth  in  each  arch;  at  the  same  time  the  relations  of  the 
dental  arches  were  made  to  harmonize  by  the  movement  mesially  of  the 
lower  teeth  on  the  abnormal  side  one-half  the  width  of  a  premolar,  while 
the  upper  incisors,  premolars,  and  canines  were  shifted  distally  to  the 
same  extent  by  the  use  of  the  expansion  arches,  D  bands,  etc.,  in  con- 
nection with  the  intermaxillary  anchorage,  all  as  described  in  the  treat- 


FiG.  638 


ment  of  cases  belonging  to  Divisions  1  and  2  of  this  class.    The  result 
is  shown  in  Fig.  938. 

Fig.  939  shows  the  facial  lines  before  treatment,  and  Fig.  940  shows 
how  greatly  they  have  been  improved  as  a  result  of  correcting  the  mal- 
occlusion.   The  weak  appearance  of  the  lower  part  of  the  face,  through 


864 


ORTHODONTIA 


its  recession,  has  been  strengthened  and  ahnost  perfect  balance  of  the 
mouth  with  the  rest  of  the  features  has  been  estabhshed. 

A  former  plan  of  treatment  by  the  writer  for  these  cases  is  shown  in 
Fig.  821,  in  which  harmony  in  the  sizes  of  the  arches  was  established 
by  extracting  the  first  upper  premolar  on  the  abnormal  side  and  retract- 
ing the  canine,  and  at  the  same  time  the  incisors  and  canines  were 
rotated  into  correct  alignment. 


}-i...  ;»:i9 


The  combination  of  the  traction-screw  and  expansion  arch,  wire 
ligatures,  etc.,  is  well  shown,  and,  indeed,  this  is  one  of  the  most 
thoroughly  efficient  devices  for  performing  tooth  movements  that  is  any- 
where found  in  the  history  of  orthodontia,  as  each  part 
most  perfectly  braces  and  assists  reciprocally  the  other 
parts  of  the  device  in  effecting  the  various  tooth  move- 
ments, and  it  was  the  occasion  of  much  pride  with 
the  writer.  But  by  this  plan  of  treatment  mutilation 
was  necessary,  with  all  its  attendant  evils  in  occlusion, 
tongue  restriction,  and  facial  deformity,  and  since  nor- 
mal occlusion  is  now  so  easily  established  by  intermax- 
illary force,  as  previously  described,  its  use  is  rarely, 
if  ever,  required. 

Class  III. — In  the  treatment  of  cases  belonging  toClass 

III,  the  degree  of  our  success,   more  than  in  any  other 

orthodontic  work,  depends  on  beginning  treatment  early. 

This  form  of  malocclusion  usually  begins  at  about  the  time  of  the 

eruption  of  the  first  permanent  molars,  although  it  may  begin  earlier,  and, 

as  the  writer  first  pointed  out,  it  is  always  associated  in  its  beginnings 

with  enlarged  tonsils,  the  habit  of  protruding  the  mandible  probably  in 


TREATMENT  SG5 

someway  art'ording  some  relief  in  breathing,  which  habit,  it  seems  reason- 
able to  the  writer  to  believe,  is  a  potent  factor  in  the  locking  of  the  first 
permanent  molars,  as  they  erupt,  into  mesial  malocclusion.  And  when 
once  the  mesio-buccal  cusp  of  the  upper  first  molar  begins  to  engage  the 
distal  incline  of  the  disto-buccal  cusp  of  the  lower  first  molar,  the  result 

Fig.  941 


mechanically  is  to  force  the  mandible  forward  on  each  closure  of  the  jaws. 
This  in  time  forces  the  deciduous  teeth  into  malocclusion,  as  well  as  each 
succeeding  permanent  tooth  as  it  erupts,  thereby  enlisting  the  other 
inclined  planes  to  act  out  of  harmony  with  nature's  intended  plan,  and 
to  assist  in  accelerating  the  forward  movement  of  the  mandible.  Not 
only  this,  but  the  bone  is  thus  stimulated  to  develop  abnormally,  which 


Fig.  942 


is  probably  furthered  to  no  small  extent  by  the  added  stimulus  of  the 
muscles  in  their  abnormal  relations  with  it. 

So,  after  the  lower  first  molars  are  locked  in  mesial  occlusion  and 
the  forces  perverted,   the  progress  must  be  and  is  rapid,   only  a  few 
years  being  necessary  to  develop  by  far  the  worst  type  of  deformity 
55 


866 


ORTHODONTIA 


the  orthodontist  is  called  upon  to  treat;  and  when  the  case  has  pro- 
gressed until  the  age  of  perhaps  sixteen,  or  after  the  jaws  have  become 
developed  in  accordance  with  the  malpositions  of  the  teeth,  all  excepting 
the  third  molars  having  erupted  by  this  time,  the  case  has  usually  passed 
beyond  the  boundaries  of  simple  malocclusion  and  into  that  realm  of 
marked  complications,  namely,  hone  deformities,  with  little  possibility, 
with  our  present  knowledge  of  the  subject,  of  affording  much  relief  by 
orthodontic  measures. 

If  these  cases  could  receive  prompt  attention  at  the  important  period 
of  the  eruption  of  the  first  molars,  the  throats  properly  treated,  and  the 
first  molars  mechanically  assisted  into  normal  relations,  and  there  com- 
pelled to  remain  by  delicate  yet  efficient  retention  for  a  few  months, 
these  unsightly  deformities  would  never  develop. 


Pig.  943 

.1 

^ 

{^B 

1 

■     mi 

P^ 

It 

There  may  be,  and  doubtless  are,  other  factors  that  enter  into  the 
production  of  these  as  yet  but  imperfectly  understood  deformities;  but 
v/e  are  convinced  that  they  are  of  minor  importance  to  those  we  have 
mentioned. 

The  time-honored  shifting  of  these  conditions  on  to  heredity  and 
supposed  degenerate  tendencies  no  longer  satisfies  or  carries  much  weight. 

Figs.  941  and  942  show  the  malocclusion  in  the  case  of  a  child,  aged 
six  years,  who  was,  and  had  been  for  some  time,  a  sufferer  from  greatly 
enlarged  faucial  tonsils.  The  first  permanent  molars  are  erupting,  and 
the  lower  ones,  in  taking  their  positions,  will  soon  become  fully  locked 
in  mesial  occlusion.  This  is  a  fair  example  of  the  beginning  of  all  these 
cases. 


TREATMENT 


8G; 


The  deciduous  teedi  are  rapidly  becoming  harmonized  to  the  abnor- 
mal occlusion,  the  lower  incisors  now  closing  mesially  to  the  upper 
incisors.  Thus  the  tendency  is  clearly  indicated  and  its  effects  shown 
on  the  facial  lines  (Fig.  943),  and  this  condition  has  developed  rapidly, 
the  contour  of  the  baby  face  being  thus  changed  in  but  a  few  months. 

luu.  944 


The  treatment  was  simple  and  easy.  Small  D  bands  were  placed 
upon  all  four  deciduous  second  molars  and  the  plain  expansion  arches 
(small)  were  adjusted,  as  per  combination  shown  in  Fig.  812,  and  force 
exerted  by  means  of  the  delicate  rubber  ligatures  made  to  engage  the 
sheath-hooks  on  the  lower  arch,  which  were  placed  well  forward,  or 


Fig.  945 


opposite  the  lateral  incisors,  and  the  other  ends  stretched  over  the  distal 
ends  of  the  sheaths  of  the  upper  anchor-bands,  the  result  being  that  in 
a  very  short  time  the  teeth  were  shifted  into  normal  relations. 

The  case  was  retained  by  means  of  two  delicate  spurs  soldered  to 
the  lingual  surface  of  delicate  bands  on  the  upper  deciduous  central 


S68 


ORTHODONTIA 


incisors,  tliese  spurs  ('xtrndinfy  downward  and  somewhat  forward  in  front 
of  the  lower  centrals,  thus  compelling  the  normal  closure  of  the  mandible, 


Fig.  IMG 


and  Figs.  044  and  !)45  show  tlie  occlusion  at  this  stage,  the  lower  decid- 
uous laterals  meantime  having  been  lost.     The  pronounced  change  in 


Fi<;.  947 


the  facial    lines  as  the  result  of    this    modified    occlusion  is  shown  in 
Fig.  946. 


TREATMENT 


m 


The  eruption  iiud  lockinn-  of  tlie  first  permanent  molars  was  now  eom- 
plete,  and  the  deciduous  upper  incisors,  with  their  retaining  bands 
and  spurs,  were  lost  through  the  natural  absorption  of  their  roots  a  few 
weeks  later,  and,  although  several  years  have  since  elapsed,  the  occlu- 


Fio.  948 


sion  is  practically  faultless  and  the  facial  lines  are  in  excellent  balance, 
as  shown  in  Fig.  947. 

Fig.  948  shows  the  malocclusion  in  another  case  of  a  patient  seven 
years  older,  in  which  the  natural  progress  of  the  deformity  is  clearly 
shown. 

The  result  in  the  inharmony  of  facial  lines  is  shown  in  Fig.  738. 

Fig.  949 


The  treatment  clearly  indicated  was  to  establish  harmony  in  the  sizes 
of  the  arches  and  normal  relations  of  the  inclined  occlusal  planes. 
Without  the  intermaxillary  force  this  would  have  been  impossible,  but 
with  it  the  desired  changes  were  effected,  and  that,  too,  quite  speedily. 


870 


ORTIIODOXriA 


The  same  coinbinution  of  ajjpliances  as  that  described  lor  tlie  last 
case  was  also  used  in  this.  The  force  necessary  to  shift  mesially  the 
upper  teeth  was  reciprocated  to  move  dislally  ;ill  of  the  lower  teeth.     It 


Fig.  950 


E  H.A. 


Fi<;.  051 


is  quite  probable  that  the  mandible  was  also  moved  distallv  somewhat. 
In  fact,  this  is  shown  in  the  facial  lines  after  treatment  (Fig.  739),  but 
the  principal  change  was  in  the  positions  of  the  crowns  of  the  teeth 
after  three  weeks'  treatment,  shown  in  P^ig.  949. 


TREATMENT 


.S71 


No  eifort  was  made  to  establish  better  relations  between  the  pre- 
molars, knowing  full  well  that  as  these  teeth  continued  their  eruption 
they  would  be  forced  more  and  more  into  their  normal  relations  through 
the  influence  of  their  inclined  occlusal  planes. 

The  retention  was  effected  as  described  in  the  section  on  retention 
for  cases  belonging  to  Class  III. 

Any  purely  orthodontic  treatment  in  such  pronounced  cases  as  that 
shown  in  Fig.  950  (facial  lines  in  Fig.  951)  is  a  waste  of  time  both  of 
patient  and  operator.  The  only  possible  relief  would  be  l)y  performing 
the  writer's  operation  known  as  "double  resection  of  the  jaw,'"  but  as 
that  comes  under  the  realm  of  surgery,  its  consideration  does  not  properly 
belong  here. 

Fig.  952 


Even  in  such  cases  as  that  shown  in  Fig.  952,  in  which  the  malocclu- 
sion has  never  passed  beyond  simple  mesial  occlusion,  yet  at  this  age  of 
the  patient  (twenty-five  years)  the  jaws  and  muscles  have  become  fixed 
in  their  abnormal  development,  and  the  result,  after  many  months  of 
patient,  persistent  treatment,  will  usually  be  found  to  be  most  discour- 
aging and  unsatisfactory.    They  are  good  cases  to  avoid. 

We  have  elsewhere  given  our  views  relative  to  the  use  of  the  chin 
retractor  and  occipital  anchorage  in  connection  with  the  treatment  of 
these  cases,  and  how  they  have  practically  become  superseded  by  the 
intermaxillary  anchorage.  The  writer  no  longer  finds  value  in  their 
use,  although  there  is  the  barest  possibility  that  they  may  still  in  some 
instances  have  use  as  an  auxiliary  to  the  intermaxillary  anchorage. 

Class  III, — Subdivision. — As  cases  belonging  to  the  subdivision  of 
Class  III  are  in  unilateral  mesial  occlusion,  the  treatment  clearly  indi- 
cated, especially  in  young  patients,  is  after  the  same    plan    we  have 


*  For  the  consideration  of  this  operation  see  the  writer's  Malocclusion  of  the 
Teeth,  seventh  edition. 


872  ORTIlODOSriA 

described  for  the  full  division,  exerting  force,  liowever,  only  on  the  side 
that  is  in  mesial  occlusion. 

In  this  short  treatise  the  writer  has  aimed  to  j)()int  out  a  simple, 
logical  system  not  only  of  diagnosticating  malocclusion,  but  also  its  treat- 
ment, from  the  simplest  to  the  most  complex  cases — and  all  from  the 
basis  of  normal  occlusion. 

And  finally,  orthodontia  is  now  one  of  the  well-recognized  specialties 
of  medicine,  and  in  its  practice  the  possibilities  for  adding  to  the  health, 
beauty,  and  happiness  of  humanity  are  so  great  as  to  make  it  a  most 
inviting  field.  Yet  it  must  be  remembered  that  the  difficulties  in  the 
practice  of  orthodontia  are  such  that  only  those  who  have  an  aptitude 
for  the  work  and  will  study  it  broadly  and  thoroughly  will  ever  be 
successful  in  its  practice,  but  for  such  a  limitless  field  and  prompt 
recognition  is  waiting. 

Orthodontia  should  be  taught  and  practised  as  a  distinct  specialty, 
for  there  is  no  specialty  in  medicine  with  more  clearly  defined  boundary 
lines.  To  the  mere  smatterer  it  is  a  most  unpromising  and  unprofitable 
field  of  labor,  but  to  those  with  an  aptitude  and  liking  for  the  work,  who 
by  study  and  patient  endeavor  master  it,  orthodontia  is  for  many  reasons 
a  most  ideal  specialty,  and  offers  opportunities  not  now  approximated 
by  any  other  in  medicine. 

Malocclusion  of  the  teeth  is  so  prevalent,  and  its  intelligent  treatment 
followed  by  benefits  so  pronounced  in  the  health,  happiness,  and  beauty 
of  the  patient,  that  although  it  is  the  newest  specialty  in  medicine  it  is 
destined  soon  to  be  recognized  as  one  of  the  most  important. 


CHAPTER    XXII 
DENTO-FACIAL  ORTHOPEDIA 

By  CALVIN  S.  CASE,  D.D.S.,  M.D. 
INFLUENCE   OF   THE   TEETH   ON   THE  PHYSIOGNOMY 

In  the  developmental  processes  of  animal  life  the  teeth  have  probably 
been  more  influential  than  any  of  the  other  organs  in  shaping  the  bones 
of  the  head — especially  in  determining  the  physical  characteristics 
of  the  physiognomy.  The  physical  shape  and  structure  of  the  jaws 
conclusively  show  the  influence  that  the  teeth  have  exerted  in  different 
species  in  response  to  nature's  effort  to  propagate  that  which  would  best 
subserve  them  in  the  performance  of  their  functions.  The  importance 
of  the  teeth,  therefore,  and  their  inherent  demand  upon  surrounding 
anatomical  structures  for  proper  means  of  development,  sustenance,  and 
use,  is  evidence  that  they  exert,  during  development,  a  more  or  less 
immediate  influence  in  determining  the  size  and  shape  of  the  maxillary 
bones,  and  thus  indirectly  are  extensively  influential  in  characterizing 
the  individual  shape  of  the  human  face. 

Often  the  position  of  the  anterior  teeth  and  alveolar  process  is  such 
as  to  impress  upon  the  contiguous  features,  even  in  repose,  certain  con- 
ditions which  vary  from  a  slight  imperfection  in  esthetic  contour  to  a 
most  distressing  facial  deformity.  Nor  are  these  dento-facial  imper- 
fections always  wholly  due  to  a  malposition  of  the  teeth,  so  much  as  to 
a  lack  of  normal  symmetry  in  the  size  or  shape  of  the  maxillary  bones 
upon  which  so  large  an  area  of  the  face  is  dependent  for  its  contour. 

Causes. — ^These  conditions  may  have  arisen  from  the  direct  inherit- 
ance of  a  parental  deformity,  or  from  the  inharmonious  union  of  undi- 
luted types.  It  is  equally  true  that  the  oft'spring  of  inharmonious  types 
often  results  in  symmetrical  conditions  which  neither  parent  possesses. 

Among  local  causes,  or  those  which  operate  after  birth  in  the  pro- 
duction of  facial  imperfections,  may  be  mentioned  habits,  impaired 
dentition,  delayed  and  injudicious  extraction  of  the  deciduous  teeth, 
and  diseases  of  the  nasopharyngeal  passages,  causing  a  lack  of  normal 
development  of  adjoining  bones,  often  accompanied  with  mouth  breath- 
ing, with  its  far-reaching  effects. 

The  influence  of  the  teeth  during  the  time  of  their  eruption  (pro- 
ducing on  the  one  hand  the  excessive  pressure  of  large  teeth  and  con- 
comitant alveolar  development,  and  on  the  other  a  lack  of  pressure  from 

(873) 


874  DEX TO-FACIAL  ORTHOPEDIA 

an  irregularity  or  injudicious  extraction)  in  effecting  a  change  in  tiie 
inherent  shape  or  size  of  the  maxillary  bones  beyond  that  which  the 
alveolar  process  is  forced  to  assume  to  accommodate  them,  has  been  a 
question  of  considerable  controversy. 

While  it  is  of  common  observation  that  bones  are  retarded  and  even 
permanendy  stunted  in  their  growth  development  by  both  natural  and 
artificial  causes,  and  thus  made  to  assume  a  diminished  size,  I  think 
it  may  i^e  stated  as  a  fact  that  there  is  no  authentic  record  of  bones 
having  been  made  to  grow,  in  the  individual,  appreciably  larger  or 
longer  than  the  normal  size,  by  artificial  force. 

By  the  early  removal  of  the  causes  of  non-development — as  in  the 
removal  of  adenoids,  which  have  retarded  the  development  of  the 
superior  maxillae  and  other  bones — the  affected  bones  may  develop  to 
their  full  normal  size  after  the  cause  is  removed,  if  properly  aided  by 
artificial  stress. 

It  is  reasonable  to  assume  that  artificial  force  cannot  cause  the  pro- 
duction of  that  which  is  commonly  seen  to  be  apparently  impossible 
by  the  strongest  of  the  natural  physical  forces  operating  during  the 
early  stages  of  childhood  development  and  through  adolescence.  I 
refer  to  those  commonly  seen  dental  protrusions,  unimaxillary  and 
bimaxillary,  which  evidently  assume  this  position  because  the  teeth 
are  too  large  for  the  natural  size  of  the  jaws  in  which  they  are  placed. 
The  pressure  of  erupting  teeth,  as  is  the  force  exerted  by  all  natural 
growth,  is  far  greater  than  one  would  imagine  who  had  not  carefully 
observed  its  effects.  Why  is  it  then  that  this  great  pressure  of  the  erupt- 
ing permanent  teeth,  crowding  their  way  in  between  the  rami  and  the 
labial  arch  does  not  cause  the  disto-mesial  enlargement  of  the  body  of 
the  mandible,  so  as  to  extend  the  chin  forward  somewhat  in  harmony 
with  the  protruded  position  of  the  teeth?  If  this  were  possible  we 
would  not  so  frequently  see  the  appearance  of  receding  chins  occurring 
with  people  whose  mandibles  are  in  full  harmony  as  regards  size,  with 
the  balance  of  the  features;  the  effect  being  purely  because  of  an 
excessive  abnormal  protrusion  of  the  lower  teeth  and  alveolar  process. 

With  bimaxillary  protrusions  the  dentures  will  frecjuendy  be  found 
in  normal  occlusion,  alignment,  and  in  proper  arch  width  with  the  pro- 
duction nevertheless  of  a  decided  abnormal  prominence  of  the  mouth, 
extending  over  the  entire  dento-facial  area  (Fig.  953). 

This  is  a  question  of  the  greatest  importance  to  consider  in  the  con- 
templation of  moving  the  lower  dentures  of  young  children  forward 
with  the  intermaxillary  force  to  place  them  in  normal  occlusion  with 
protruded  uppers — an  operation  that  is  questionably  advocated  and 
unfortunately  extensively  and  indiscriminately  practised  today. 

If  one  could  be  sure,  at  these  early  stages,  that  the  lower  dentures 
were  destined  to  be  retruded  in  relation  to  the  mandible  and  that  this 
forward  movement  would  not  ultimately  result  in  a  receding  chin  effect 


INFLUENCE  OF   THE   TEETH  ON   THE  PHYSIOGNOMY      875 

it  would  be  excusable  and  demanded.     It  unfortunately  happens  in  a 
large  proportion  of  these  cases  that  the  disto-mesial   malocclusion  of 


Fk;.  953 


the  buccal  teeth  is  due  solely  to  an  inherent  protrusion  of  the  upper 
dentures,  which  in  the  operation  of  adjusting  the  occlusion  to  normal 
with  the  intermaxillary  force,  the  uppers  are  retruded  only  one-third 
or  at  most  one-half  as  much  as  they  should  be  to  correct  the  facial 


Fig.  954 


deformities;  the  whole  resulting    in   bimaxillary  protrusions    stamped 
upon  many  faces  for  life  whose  features  might  have  been  handsome 


876 


DEXTO -FACIAL  ORTIIOJ'EDI A 


Fig.  955 


had  tlie  ii})j)er  first  or  srcoiul  premolars  hoeii  extracted  and  the  UUhuI 
teeth  fully  retruded,  with  no  iiiovenient  of  the  lower  dentures  and  upper 

buccal  teeth,  except  that  re(|uired  to  adjust 
the  closure  to  a  perfect  interdigitating 
occlusion  (Fig.  954). 

Irregularities  of  the  teeth  caused  by  dis- 
eases of  the  naso-maxillary  sinuses  and, 
secondarily,  by  a  lack  of  development  of 
the  maxillary  bones,  pertains  directly  to 
the  upper  jaw,  although  the  lower  teeth 
may  also  be  forced  into  malposition 
through  the  influences  of  imperfect  oc- 
clusion, and  even  the  mandible  itself 
may  be  changed  in  shape  by  the  concomi- 
tant mouth  breathing,  causing  an  open- 
bite  malocclusion. 
With  the  primary  cause  of  these  conditions  removed  at  an  early  age, 
the  retarded  development  of  the  superior  maxilhie  may  be  made  to  assume 


Fig.  956 


its   normal   size  and  shape.     A  peculiarly  fortunate  possil)ility  arises 
from  the  fact  that  a  retruded  incisive  portion  of  the  maxilhe  may  be 


INFLUENCE  OF  THE  TEETH  ON  THE  PHYSIOGNOMY      877 

forced  forward  to  a  normal  position  with  a  bodily  protruding  movement  of 
the  incisor  teeth.  It  would  seem  that  it  was  only  the  alveolar  ridge  that 
moved,  were  it  not  for  the  fact  that  in  those  cases  where  the  end  of  the 
nose  is  carried  backward  through  a  lack  of  forward  growth  development 
of  the  incisive  process  it  is  commonly  carried  forward  and  straightened 


Fig.  957 


Fig.  958 


in  this  movement  (see  Figs.  968,  973,  and  978).  When  it  is  remembered 
that  the  end  of  the  nose  is  supported  by  the  cartilaginous  septum 
attachment  to  the  nasal  spine  of  the  superior  maxillary  bones,  it  will 
be  seen  that  the  incisive  portion  of  the  maxillae  proper  must  move  to 
carry  the  end  of  the  nose  forward  as  it  frequently  does. 

The  bodily  forward  movement  of  the  labial  teeth  is  now  an  operation 
that  is  quite  as  easily  accomplished  with  the  proper  apparatus  as  any 


Fig.  960 

!     ^ 

^^^^fc^ 

■■■■■'■^ 

r-. 

5 

Wf^ 

/ 

HB                  ^ 

■  A 

W- 

J 

'  ^. 

of  the  other  extensive  movements  of  regulating.  For  patients  not  older 
than  twelve  or  fourteen  years,  the  entire  incisive  alveolar  ridge  is  com- 
monly carried  forward  with  the  teeth. 

This  is  well  shown  in  the  accompanying  illustrations  made  from  the 
models  of  a  face  when  presented  at  twelve  years  of  age,  showing  a  decided 
retrusion  of  the  upper  incisor  teeth  involving  the  entire  incisive  alveolar 


878  DENTO-FACIAL  ORTHOFEDIA 

ridge.  Other  parts  of  the  jaws  and  teeth  were  in  normal  size,  relation, 
and  occlusion. 

The  illustrations  on  the  left  show  different  views  of  the  case  at  the 
beginning  of  the  operation,  and  those  on  the  right  after  the  teeth  and 
alveolar  ridge  had  been  bodily  protruded  with  the  contouring 
apparatus  shown  in  Fig.  901. 

This  cut  was  made  from  a  photograph  of  the  apparatus  which  the 
patient  wore,  and  which  after  removal  was  placed  on  her  dental  casts 
as  shown. 

In  dental  orthopedia  we  possess  the  great  advantage  over  general 
orthopedia  of  applying  force  directly  to  the  bone  itself,  through  the 
medium  of  the  teeth,  without  the  intervention  of  the  soft  and  sensitive 
tissues. 

Fig.  9(Jl 


The  teeth  embedded  in  the  alveolar  process  that  in  turn  is  firmly 
united  to  the  true  bone  may  be  considered,  when  in  the  grasp  of  a  regu- 
lating machine,  as  an  integral  part  of  it,  firmly  and  direcdy  attached 
to  that  part  of  the  bone  we  desire  to  move,  and  capable  of  exerting 
the  quality  and  direction  of  force  the  machine  gives  to  them. 

This  force  being  applied  unitedly  to  a  number  of  teeth  standing  side 
by  side,  the  svn-rounding  and  contiguous  bone — which  is  largely  a  can- 
cellated structure — is  carried  bodily  in  the  direction  of  the  force;  not 
by  the  fracture  of  its  substance  or  to  any  great  extent  by  a  metamor- 
phosis of  tissue,  but  by  the  bending,  condensation,  and  elongation  of  its 
cellular  structure;  the  whole  adapting  itself  to  a  new  form,  in  which 
position  the  immediate  interstitial  tension  of  its  particles  is  soon  relieved 
and  brought  to  equilibrium  by  nature — although  it  may  require  to  be 
held  in  that  position  for  many  months  before  there  is  an  entire  relief 
from  the  inherent  tendency  to  return  to  the  former  position. 

Dento-facial  Diagnosis. — In  contemplating  the  treatment  of  a  dental 
irregularity  a  careful  study  of  the  physiognomy  in  different  attitudes 


PRINCIPLES  OF  FACIAL  ORTHOPEDIA  <S79 

of  expression  should  be  made,  with  the  view  of  determining  the  relative 
position  of  teetli  and  facial  contours.  The  value  of  a  careful  preliminary 
facial  examination  and  comparison  cannot  be  overestimated,  for  it  is 
often  the  only  guide  to  correct  treatment. 

For  instance,  since  it  has  become  possible  to  expand  or  retract  the 
anterior  portion  of  the  upper  apical  zone  with  the  surrounding  bone  in 
which  the  moving  roots  are  embedded,  we  are  no  loneer  confined  to  the 
possibility,  and  frequent  questionable  propriety,  of  permanently  moving 
the  lower  jaw  forward  or  backward  to  correct  a  facial  deformity  which 
pertains  exclusively  to  the  upper  maxillae  and  middle  features  of  the 
face. 

PRINCIPLES  OF  FACIAL  ORTHOPEDIA 

The  portion  of  the  human  face  that  it  is  possible  to  change  with  a 
dental  regulating  apparatus  may  be  said  to  lie  between  two  diverging 

Fig.  962 


A,  upper  apical  zone 

B,  upper  coronal  zone 

C,  lower  coronal  zone 

D,  lower  apical  zone 


lines  which  arise  at  a  point  below  the  ridge  of  the  nose  and  curve  down- 
ward to  inclose  the  alae  and  depressions  on  either  side;  thence  laterally 
to  encircle  a  portion  of  the  cheek,  and  downward  to  inclose  the  entire 
lower  lip  and  labio-mental  curve  (Fig.  962.) 

Within  this  ovoidal  area  the  slightest  change  of  muscular  movement 
expressive  of  the  emotions  will  produce  an  apparendy  marked  effect 
upon  the  entire  physiognomy.  The  same  is  true  of  any  physical  imper- 
fection of  contour,  particularly  around  the  mouth.  It  is  here  that  an 
inherited  or  acquired  lack  of  symmetry  in  the  size,  shape,  or  position  of 
the  teeth  and  jaws  produces  those  marked  changes  of  facial  contour  which 


880  DENTO-FA  (  I A  L  OU  T  IK) /'EDI  A 

characterize  the  several  classes  of  deiito-facial  deformities.  This  area 
maybe  termed  the"  changeable  area"  in  contradistinction  to  the  more 
stable  features,  or  "iinchantfeable  area." 

For  convenience  of  ready  reference,  the  features  in  that  jjortion  of 
the  changeable  area  which  are  bounded  laterally  by  the  naso-labial  lines 
may  be  divided  into  fcMir  segments  as  shown. 

In  the  preliminary  examination  of  the  physiognomy  from  a  j)urely 
esthetic  standpoint  with  a  view  of  correcting  a  dento-facial  deformity 
or  imperfection,  by  apj:)lying  force  to  the  teeth,  there  are  certain  prom- 
inent features  to  be  especially  observed  and  their  relative  position  care- 
fully noted.  These  may  be  divided  into  two  classes:  First,  those  which 
lie  in  the  unchangeable  area,  as  the  forehead,  bridge  of  the  nose,  malar 
prominences,  and  chin;  second,  those  in  the  changeable  area. 

The  four  segments  in  the  latter  class  shown  in  Fig.  962  are  change- 
able in  their  relations  to  each  other,  and  also  in  their  individual  relation 
to  features  in  the  unchangeal)le  area.  For  instance,  it  is  possible  to  pro- 
trude or  retrude  the  upper  portion  of  the  upper  lip  with  the  depressions 
on  each  side  of  the  nose,  the  nasal  septum,  and  the  end  of  the  nose, 
without  changing  the  lower  portion  of  the  upper  lip  in  its  relation  to 
other  parts.  The  same  is  true  of  the  other  segments — in  fact,  a  retrusion 
of  the  upper  coronal  zone  and  a  protrusion  of  the  upper  apical  zone 
may  be  accomplished  at  the  same  time  (see  Figs.  971  and  972). 

That  part  of  the  cheeks  which  lies  over  the  premolars  and  first  molars 
will  frefjuently  be  rounded  out  to  a  fuller  contour,  although  the  causes 
which  operate  in  this  result  are  not  direct  as  in  the  changeable  area 
proper.  The  lateral  expansion  or  contraction  of  the  dental  arches  will 
often  change  the  contour  of  the  cheeks  with  no  effect  upon  the  labial 
area,  if  the  anterior  teeth  remain  unchanged  in  position.  Again,  a  decided 
retrusion  of  the  anterior  teeth  and  process  with  no  lateral  expansion 
of  the  arch  will  invariably  result  in  giving  to  the  cheeks  a  fuller  contour, 
by  relieving  the  tension  of  muscular  tissues.  The  same  result  will 
often  be  obtained  in  closing  the  characteristic  open  bite  of  a  mouth- 
breather  by  grinding  the  posterior  teeth,  and  also  by  retracting  a  prog- 
nathous lower  jaw. 

In  a  study  of  profiles  we  frequently  observe  a  lack  of  j)erfect  har- 
monv  in  the  position  of  the  chin.  The  lower  jaw  is  apparently  protruded 
or  retruded,  so  as  to  mar  the  esthetic  perfection  of  the  physiognomy, 
and  yet  were  these  same  faces  examined  by  a  trained  observer  he  would 
find  in  a  large  proportion  the  lower  jaw  in  perfect  harmony  with  the 
unchangeable  area,  and  that  the  appearance  of  its  malposition  was  an 
effect  due  wholly  to  a  protrusion  or  retrusion  of  the  upper  jaw  and  teeth. 
In  other  words,  it  is  a  common  error  to  imagine  the  chin  imperfectly 
posed  because  it  is  not  in  harmonious  relations  to  the  other  features 
of  the  changeable  area,  instead  of  comparing  it,  as  we  should  do,  to  the 
more  stable  or  unchangeable  features  of  the  physiognomy. 


UPPER  PROTRUSIONS  881 

In  examining  the  physiognomy  of  a  patient,  the  head  should  be  in 
an  upright  position,  on  a  Hue  with  that  of  the  observer,  and  the  face 
studied  from  different  angles  while  in  repose  and  in  action. 

While  looking  at  the  profile  in  repose  the  most  important  thing  to 
determine  is  the  relative  position  of  the  chin  with  the  forehead,  malar 
prominences,  and  bridge  of  the  nose.  If  its  position  is  harmonious 
with  the  unchangeable  area  and  the  lower  lip  is  well  posed,  it  indicates 
that  the  operation  of  facial  contouring  should  be  performed — if  any- 
where— upon  the  upper  jaw  and  teeth.  For  if  the  first  and  second 
segments  are  abnormally  protruded  it  will  cause  a  chin  to  appear  retruded 
that  is  perfecdy  harmonious  in  its  relations  to  the  principal  features  of 
the  face.  Again,  a  retruded  or  contruded  upper  arch  with  a  depression 
of  those  features  which  are  supported  by  the  superior  maxilUe  will 
cause  a  perfecdy  posed  lower  jaw  and  chin  to  appear  protruded  or  prog- 
nathous; as  instanced  by  many  cases  illustrated  in  Section  IV,  in  which 
the  facial  effect,  before  treatment,  was  that  of  protruded  mandibles,  but 
which  were  perfectly  corrected  by  a  forward  movement  of  the  upper 
incisors. 

UPPER  PROTRUSIONS 

Fig.  983  will  serve  to  partially  illustrate  this  class  of  dento-facial  irreg- 
ularities. This  case  is  one  in  which  the  roots  as  well  as  the  crowns 
were  protruded. 

The  intermediate  stage  of  the  operation  shows  conditions  after  the 
crowns  of  the  labial  teeth  had  been  retruded  following  the  extraction 
of  the  first  bicuspids,  with  an  apparatus  similar  to  that  shown  in  Fig.  964. 

It  will  be  seen  that  notwithstanding  the  fact  that  the  retruded  force 
was  applied  through  the  medium  of  the  retruding  bow  at  the  gingival 
borders  of  the  front  teeth  there  was  left  quite  a  decided  prominence 
along  the  upper  portion  of  the  upper  lip. 

The  final  stage  of  the  operation  shows  the  greatly  improved  facial 
outlines  after  the  roots  had  been  retruded  with  an  apparatus  similar 
to  that  shown  in  Figs.  965  and  966. 

If  the  operation  of  "jumping  the  bite"  were  performed  in  cases  of 
this  character  there  would  no  doubt  be  an  improvement  of  the  original 
appearance  of  the  physiognomy,  by  bringing  the  chin  and  lower  lip  into 
more  perfect  harmony  with  the  upper;  but  this  would  not  be  correct 
treatment,  because,  as  will  be  observed,  the  chin  is  not  far  from  a 
perfect  position  when  compared  with  other  features  of  the  unchangeable 
area. 

The  principles  involved  in  the  correction  of  this  class  of  facial  deform- 
ities may  be  diagrammatically  illustrated  as  follows: 

Fig.  967  is  a  profile  view  of  a  typical  case  of  protruded  upper  teeth. 
It  will  be  observed  that  the  chin  appears  retruded. 
66 


882 


DKX'W-FACIAL  ORTUOI'KDIA 


Fi<r.  !)(iS  shows  the  improved  effect  that  would  l)e  j)ro(hic('d  hy  "jmiij)- 
ino;  the  hite"  in  bringing  the  low^er  Hp  and  chin  into  more  perfect  har- 
mony with  the  upper;  yet  not  to  he  compared  with  that  perfection  of 


Fig.  964 


UPPER  PliOTliU SIGNS 


883 


symmetrical  contour  shown  by  Fig.  969,  where  the  chin  and  lower  lip  are 
permitted  to  remain  in  their  original  harmonious  position  while  the  end 
of  the  nose  and  upper  lip  are  retruded  into  harmony  with  the  whole. 
The  three  faces  have  been  made  exactly  alike  with  the  exception — 
as  shown  b\   the  cross  lines-  of  certain  mechanical  movements  of  the 


Fig.  9G5 


profile  outlines  in  the  changeable  area.  In  Fig.  9(38  the  outlines  of 
the  lower  zones  and  chin  are  placed  farther  forward,  and  in  Fig.  9()0 
the  outlines  of  the  upper  zones  are  carried  back,  as  they  would  be  by  a 
retruding  apparatus  attached  to  the  teeth. 


Fig.  966 


In  comparing  Figs.  967  and  969  the  difference  in  esthetic  effect  is 
quite  striking,  and  it  is  one  also  which  would  seem  to  be  hardly  possible 
with  so  little  change  in  the  outlines  of  a  comparatively  small  area.  Bv 
cutting  a  piece  of  black  paper  to  the  exact  outline  of  Figs.  969  and 
placing  it  upon  Fig.  967  the  real  and  only  difference  in  the  two  figures 
can  be  plainly  seen — as  in  Fig.  970. 


884 


DKS  TO-FA  ( 7 .1 L  OH  T  IK)  I' EDI  A 


When  siK'h  a  chantje  is  produced  in  the  features  of  a  human  fiice  the 
difference  is  greatly  enhanced  because  of  tlie  harmonious  perfection  of 
other  contours  not  sliown  by  the  figures. 


Fig.  9G7 


Fig.   969 


Fig.  968 


Fig.  970 


It  is  a  noteworthy  fact  that  a  very  Httle  change  in  the  peripheral 
shape  or  position  of  certain  bones  of  the  face  on  which  the  features  are 
dependent  for  their  character  and  form — a  change  so  trifling  that  it  could 
hardly  be  measured — resulting  in  a  slight  filling  out  or  depression  of 


T'PPER  PROTRrsroxs 


885 


certain  contours,  will  often  heautifv  to  a  remarkable  deiiTee  the  appear- 
ance of  a  face  that  would  otherwi.-^e  he  (|uite  ])lain  and  unattractive. 

This  is  true  of  all  the  more  common  cases  of  uj)per  protrusion  and 
retrusion  which  show  an  abnormal  prominence  or  depression  along  the 
upper  as  well  as  the  lower  portion  of  the  upper  lip,  and  especiallv  of 
those  which  seem  to  involve  the  entire  incisive  process,  influencing  the 
anteroposterior  position  of  the  wings  and  end  of  the  nose. 


Fig.     971 


In  cases  of  protrusion,  by  applying  a  retruding  force  especially 
directed  to  the  roots  and  crowns  of  the  anterior  teeth,  the  surroundine- 
alveolar  process  will  be  forced  back,  allowing  the  upper  lip  to  fall  into 
a  more  graceful  and  easy  pose,  leaving  the  nostrils  less  broad  and  open, 
the  curve  of  the  nose  straightened,  and  its  pug-like  appearance  removed. 


Fig.  972 


When  an  upper  protrusion  is  due  alone  to  a  labial  inclination  of 
large  crowded  teeth,  with  no  marked  protrusion  over  the  apical  zone,  or 
in  segment  1,  the  extraction  of  the  first  or  second  bicuspids  is  indicated, 
and  the  application  of  force  to  the  crowns  at  such  points  and  in  such 
direction  as  will  best  overcome  the  malposition. 


886  DENTO-FACIAL  ORTIIOPKDIA 

Many  instancrs  have  arisen,  in  I  lie  j)rac(ice  of  denfists  who  were 
oj)|)ose(l  to  tiie  extraction  of  teeth,  when  the  above  condition  has  actually 
been  pro(hiee(l  in  the  operation  of  crow<Hn<i;  irreijfnlar  teeth  into  align- 
ment that  were  too  lar^e  for  an  already  j)erfeetly  harmonious  maxillary 
arch  (see  Figs.  1)92  to  1H)5  inclusive,  in  Section  \). 

Instances  frequently  arise  in  which  the  jiosition  and  labial  inclination 
of  the  upper  anterior  teeth  produce  a  relative  protrusion  of  the  incisal 
zone  and  a  contrusion  of  the  apical,  with  a  protrusion  of  the  lower 
portion  of  the  upper  lip  and  a  slight  depression  of  the  upper  portion, 
deepening  the  naso-labial  depressions  (see  Figs.  971  and  972).  If  the 
depression  of  segment  1  be  not  too  ]>ronounced,  it  may  be  restored  by  a 
slight  forward  movement  of  the  anterior  apical  zone,  accomplished  in  the 
retrusion  of  the  incisal  zone — by  force  applied  at  the  incisal  ends  of 
the  teeth  alone,  with  the  view  of  producing,  as  far  as  possible,  a  fulcrum 
force  at  the  lingual  margins  of  the  alveola. 

With  marked  cases  of  this  character  the  protruded  position  of  the 
uppers  demands  the  extraction  of  the  first  or  second  bicuspids,  and 
then  if  the  roots  of  the  labial  teeth  are  decidedly  retruded  it  will  be 
found  necessary  to  employ  a  contouring  apparatus  to  move  the  roots 
forward  while  the  crowns  are  retruded  with  the  fulcrum  bow  of  the  same 
apparatus. 

In  contradistinction  to  this  class  of  deformities,  there  is  another 
quite  as  common — although  not  so  frecjuently  recognized  as  an  abnor- 
mality—in which  all  the  conditions  are  reversed,  in  that  the  teeth  have 
a  lingual  inclination  with  protrusion  of  the  apical  zone  and  maxilhe. 

The  teeth  of  these  cases  are  commonly  regular  in  alignment,  and 
owing  to  their  lingual  inclination  the  occlusal  zone  may  be  in  proper 
relative  position  (Fig.  973). 

The  facial  imperfection  which  consists  principally  in  a  prominence 
or  bulging  along  the  higher  portions  of  the  upper  lip  and  in  the  region 
of  the  nasal  alae  is  often  quite  pronounced.  A\Tien  this  is  caused  partly 
bv  the  cariine  roots  the  difficulties  are  much  increased  in  the  case  of 
patients  older  than  thirteen  years.  The  fact  that  the  roots  of  the  canines 
are  surrounded  by  the  most  dense  portion  of  the  alveolar  process,  and  their 
movement  bodily  in  a  posterior  direction  requiring  the  resorption  of  a 
large  portion  of  bone,  makes  this  operation  one  of  the  most  difficult  in 
dental  orthopedia,  even  though  the  first  premolars  are  extracted  to  permit 
the  movement. 

Fig.  973  is  from  the  models  of  a  patient  over  twenty  years  of  age, 
and  will  serve  to  illustrate  a  case  before  and  after  treatment  of  abnormal 
protrusion  of  the  roots  of  the  upper  anterior  teeth,  alveolar  process,  and 
maxilla^ — the  axis  of  the  incisors  being  inclined  lingually. 

It  will  be  observed  that  the  canines  have  been  moved  bodily  in  a 
distal  direction  notwithstanding  the  advanced  age  of  the  patient. 

If  regulating  appliances  are  properly  constructed  that  will  permit 


UPPER   DENTAL  AND  MAXILLARY  RETRUHIONS 


887 


tile  production  of  an  independent  static  fulcrum  at  the  occlusal  ends  of 
the  teeth,  so  that  the  entire  power  of  the  machine  may  be  directed  and 
maintained  upon  the  roots  (see  Figs.  1014  and  1015,  in  Section  VI), 
perfect  contrnsion  of  the  prominence  will  slowly  but  surely  result. 

If  the  teeth  are  crowded,  overlapping,  or  turned  on  their  axes,  a 
correction  of  alignment  may  reqnire  the  extraction  of  a  bicuspid  on 
each  side  in  order  to  regulate  them  without  an  abnormal  protrusion  of 
their  crowns.  This  is  especially  indicated  when  much  retrusion  of  the 
canine  roots  is  desired. 

Fk;.   973 


UPPER  DENTAL  AND  MAXILLARY  RETRUSIONS 


Facial  imperfections  which  are  due  to  insufficient  fulness  of  contour 
in  the  central  features  of  the  physiognomy  are  quite  common,  and  vary 
in  degree  from  conditions  that  are  hardly  noticeable  to  those  which  may 
well  be  classed  among  the  most  unhappy  of  facial  deformities. 

There  are  several  distinct  types  of  this  class  of  facial  irregularity 
which  are  mainly  due  to  an  interruption  in  the  development  of  the 
superior  maxilla,  although  many  arise  from  direct  inheritance. 

The  primary  cause  of  these  conditions  may  be  often  very  obscure 
and  admit  of  nothing  more  tangible  than  conjecture,  and,  not  unlike 


888 


DENTO-FACIAL  OPTIIOPEDIA 


many  of  the  causes  of  irregular  teeth,  be  really  immaterial  to  the  work 
of  correction. 

Reiruded  Upper  Incisors  and  hticrmaxUlary  Process. — In  the  more 
pronounced  deformities  of  this  class  the  physiognomy  will  often  appear 
flattened,  with  prominent  cheek  bones  and  j)rotruding  chin  and  lower 
lip;  the  upper  incisors  occlude  evenly  with  or  {)osterior  to  the  lower 
incisors,  and  at  times  are  extensively  inlocked  in  this  position,  as  instanced 
by  the  case  fully  described  and  illustrated  in  Section  I. 

The  upper  incisors,  which  alone  have  their  origin  in  the  incisive 
process,  are  in  their  entirety  posterior  to  a  normal  relative  position. 
The  labial  inclination  of  the  crowns,  together  with  the  deepened  incisive 
fossae,  will  show  at  once  the  contruded  position  of  the  roots  and  their 
maxillary  surroundings. 


Fir..   974 


The  upper  lip  resting  upon  the  retruded  teeth  and  the  overlying 
process  is  proportionately  depressed.  Nor  does  the  facial  defect  end 
here.  The  entire  lower  portion  of  the  nose,  su})ported  as  it  is  by  the 
nasal  cartilages  which  spring  from  the  anterior  nasal  spine  and  lateral 
borders  of  the  nasal  orifice,  is  often  decidedly  affected  in  shape  by  the 
retruded  position  of  its  supports. 

WTien  there  is  a  decided  retrusion  of  the  entire  upper  lip   and  lower 


UPPER  DENTAL  AND  MAXILLARY  RETRUSIONS 


889 


portion  of  the  nose,  with  ahv  resting-  in  deep  depressions  caused  hy  the 
unusual  prominence  of  the  naso-labial  folds,  the  effect  is  that  of  an 
abnormal  j)rotrusi()n  of  surrounding  psirts,  producino-  at  times  a  starUing 
expression  of  maturity  that  is  only  common  to  persons  of  advanced  age. 
This  expression  can  be  seen  in  Fig.  974,  which  is  that  of  a  girl  only 
twelve  years  of  age,  and  will  serve  as  a  type  of  cases  commonly  met 
with  in  practice. 


Fig.   975 


Fk;.   976 


Retruded  and  Contracted  Dental  and  Maxillary  Arch. — In  this  class 
of  deformities  the  physiognomy,  in  the  more  pronounced  cases,  has 
much  the  same  characteristics  as  those  described  above,  but  presenting 
a  more  general  retraction  of  the  central  features,  with  less  pronounced 
naso-labial  folds.  The  nose  is  often  thin  and  the  nostrils  pinched;  and 
although  the  end  of  the  nose  may  be 
depressed,  the  distance  from  the  tip  to 
the  more  depressed  lip  is  often  length- 
ened. If  the  patient  is  a  "mouth- 
breather"  with  the  typical  "open  bite," 
the  deformity  and  the  difficulties  attend- 
ing its  reduction  will  be  greatly  in- 
creased. 

Fig.  975  is  from  a  profile  model  of  a 
face  of  this  class.  Fig.  976  is  from  the 
same  model  photographed  at  a  slightly 
different  angle  to  show  the  angularity  of 
the  features. 

Fig.  977  is  a  view  of  the  teeth  in  natural  occlusion.  The  lower  first 
premolars  have  been  removed  preliminary  to  retruding  the  anterior  teeth 
to  reduce  the  abnormal  protrusion  of  the  lower  lip  and  esthetically 
deepen  the  curve  between  the  border  of  the  lip  and  the  chin.  The 
figure  has  the  appearance  of  a  perfect  occlusion  of  all  the  molars,  whereas, 
on  account  of  the  very  great  narrowness  of  the  upper  jaw,  the  buccal 


890  DENTO-FACIAL  ORTHOI'EDI A 

cusps  of  llio  second  molars  only,  occluded  with  the  linffual  cusps  of  die 

lowers. 

Fig.  978  shows  palatal  views  of  the  upj)er  arch  before  and  after  treat- 
ment. 

Flu.  978 


Fig.  979  is  a  view  of  teeth  in  natural  occlusion  after  treatment.  The 
entire  upper  dental  arch,  especially  at  the  apical  zone,  was  considerably 
enlarged.  The  "open  bite"  was  partially  closed  by  grinding  the  molars 
and  partly  by  extruding  the  teeth  anterior  to  the  molars  with  small 
rubber  bands  extending  from  the  ujjper  to  the  lower  teeth.  Fig.  9S0 
is  from  a  model  of  the  face  after  treatment. 

Fi(i.   979  Fio.  980 


As  mentioned  in  Section  II,  a  depression  of  the  central  features 
such  as  described  is  often  mistaken  for  a  prognathous  jaw,  and  treated 
accordingly. 

A  slight  retraction  of  the  lower  jaw  will  in  nearly  every  case  of  this 
character  produce  an  improvement  in  the  facial  aspect,  because  the  chm 
and  lower  lip  are  brought  into  more  perfect  harmony  wnth  the  depressed 
central  features.  Such  a  change,  however,  when  it  is  not  demanded, 
can  never  cause  the  beautifying  effect  produced  by  forcing  the  depressed 


UPPER.   DENTAL  AND   MAXILLARY  RETRl^SIONS  S91 

facitil    features— in   segments    1     and    2— forward,    thus    hriiif^nng   into 
perfect  harmony  the  entire  physiognomy. 

Fici.  981  Fig.  982 


This  can  'be  verified  with  any  profile  view  of  a  typical  case^as  Fig. 
981.    Fig.  982  is  the  same  face,  except  that  the  chin  and  lower  lip  have 

Fig.  983  Fig.  984 


been  retruded,  producing  a  certain  improvement,  but  not  to  be  com- 
pared with  Fig.  983,  where  the  chin  and  lower  lip  retain  the  same  relative 


S92 


DENTO-FACIAL  OUT  HOP  EDI. \ 


])<).siti()ii  to  the  iiiicluuiociiMe  area  as  in  Fi^^  <)S1,  while  sc^mionts  1  and  2 
have  l)een  cairied  Forward,  with  a  result  which  jjroves  (not  alone  in 
theory,  l)Ut  in  j)ra('tice)  this  to  be  the  only  true  course  to  l)rin<,f  about 
an  harnior'.ous  and  esth.-tie  adjustment  of  all  the  features  of  the  physi- 
of^noniy.  Fig.  9X4  shows  the  actual  diti'erence,  which  may  be  verified 
upon  trial,  between  Figs.  981  and  983. 

Fio".  985  w'ill  serve  to  illustrate  the  common  result  in  practical  oper- 
ations of  this  character. 

The  contouring  apparatus  (Fig.  1011)  that  is  used  to  accomplish  these 
results  is  fullv  described  in  Section  VT.       \\'ith   it  the  apical   /one  of 


Fig.  985 


the  anterior  teeth  may  be  enlarged  and  advanced  to  any  desired  degree; 
while  the  movement  and  inclination  of  the  crowMis  are  under  the  })er- 
fect  control  of  the  oj^erator. 

In  this  operation  it  will  be  found  in  a  majority  of  cases,  and  especially 
with  those  which  are  begun  as  early  as  thirteen  or  fourteen  years  of  age, 
that  the  entire  incisive  portion  of  the  upper  jaw  may  be  carried  bodily 
forward  with  the  roots  of  the  incisors. 

The  depressed  features  of  the  physiognomy — in  segments  1  and  2 
— that  are  dependent  for  their  contour  upon  that  portion  of  the  maxillfie 
are  thus  brought  into  perfect  harmony  with  other  features  of  the  face. 

It  is  not  here  implied  that  there  are  not  many  cases  of  real  prog- 


THE  SAVING  AND  EXTRACTION  OF  TEETH  S,\)y> 

nathoiis  mandible  in  which  its  retraction,  if  possible,  woukl  produce  a  most 
desirable  result;  nor  that  such  an  operation  is  impossible  if  recognized 
and  treated  sufficiently  early  with  properly  adjusted  apparatus  per- 
sistently worn.  The  body  of  the  mandible  can  certainly  be  forced  back 
to  a  more  posterior  position  in  its  relations  to  the  upper,  pardy  by  bend- 
ing the  rami  and  necks  of  the  condyles,  and  partly  by  absorption  of  the 
posterior  wall  of  the  glenoid  fossae. 

The  many  failures  that  have  attended  these  operations  have  been 
largely  due  to  the  advanced  age  of  the  patients  and  much  to  the  fact 
that  the  apparatus  is  dependent  upon  the  will  or  caprice  of  the  patient 
for  its  persistent  application. 

On  account  of  the  early  maturity  and  ossification  of  the  mandible 
these  operations  should  be  undertaken  as  early  as  from  five  to  ten  years 
of  age. 

The  caps  fitted  to  the  head  and  chin  should  be  made  to  exert  a  uniform 
pressure  over  the  surfaces  upon  which  they  rest,  admit  of  free  ventila- 
tion, and  the  whole  apparatus  when  in  place  should  have  no  projecting 
parts  which  will  interfere  with  the  comfort  of  the  patient  at  night. 


THE  RELATIONS  OF  THE  PHYSIOGNOMY  TO  THE  SAVING  AND 
EXTRACTION  OF  TEETH 

In  its  widest  scope  this  subject  includes  the  propriety  of  saving,  and 
on  the  other  hand,  the  propriety  of  extracting  certain  teeth  of  the  decidu- 
ous as  well  as  the  permanent  dental  arches  which  in  any  way  influence 
the  prevention,  the  production,  or  the  correction  of  dento-facial  irregu- 
larities. Two  phases  of  this  subject  will  be  here  presented.  The  first 
will  be  in  regard  to  the  saving  or  the  extraction  of  the  upper  premolars 
for  patients  older  than  fourteen  years,  to  correct  a  dental  irregularity;  the 
second  will  deal  with  the  early  extraction  of  the  premolars  to  prevent 
an  abnormal  upper  protrusion. 

In  the  common  form  of  dental  irregularity  shown  by  Fig.  986,  espe- 
cially if  only  the  model  of  the  upper  jaw  were  the  subject  of  study,  it 
would  in  all  probability  be  decided  to  extract  the  first  premolars  as  the 
best  course  to  pursue  as  a  first  step  toward  securing  a  perfect  alignment 
of  the  dental  arch;  and  the  proceeding  would  be  probably  correct  as  far 
as  the  upper  teeth  alone  were  concerned.  And  again,  if  both  upper  and 
lower  models  were  studied  in  occlusion  and  the  irregularity  of  the  lower 
arch  was— as  is  usually  the  case — in  correspondence  with  that  of 
the  upper,  as  shown  in  Fig.  987,  the  extraction  of  the  lower  first  pre- 
molars would  doubdess,  and  correctly,  be  decided  upon.  This  plan  of 
correction  might  even  be  decided  upon  after  a  superficial  study  of  the 
face  of  the  patient,  which  we  may  suppose  to  be  similar  to  that  shown 
in  Fig.  988.    Certainly  the  extraction  of  the  lower  first  premolars  which 


894 


DENTO-FACIAL  ORTHO/'KDIA 


have  just  l)eifiin  to  t'ruj)t,  and  tlie  retraction  of  tlie  anterior  teeth  would 
reduce  the  aj)parent  protrusion  of  the  h)\ver  lip  and  bring  it  into  more 
perfect  harmony  with  the  depressed  upper  lip. 

Yet  when  this  face  is  carefully  studied  from  the  higher  standpoint 
of  esthetic  (levelo])nient  it  becomes  evident  that  the  chin  and  lower  lip 
are   not    })rotru(le(l,    in    their  relations   to   the   malar   j)roininences,   tlw 


Vv:  086 


Fi<;.   987 


bridge  of  the  nose,  and  the  forehead,  but  that  the  central  features  of  the 
physiognomy  are  depressed  even  to  a  decided  retracti(Mi  of  the  lower 
j)ortion  of  the  nose;  and  that  which  is  really  demanded  in  this  case  is  the 
advancement  or  forward  movement  of  the  entire  intermaxillary  portion 
of  the  jaw  and  incisor  teeth;  and  further,  every  tooth  in  that  dental  arch 
is  necessary  for  the  ultimate  retention  of  the  several  parts  in  their 
corrected   position. 


Fic.   9S9 


In  the  correction  of  malformations  which  demand  the  protrusion  of 
the  incisors  l)odily  with  the  roots  and  intermaxillary  process,  the  posi- 
tion of  the  canines,  as  in  this  case,  will  frequently  prevent  the  j)roper 
attachment  and  application  of  apparatus  for  producing  the  desired 
effect;  so  that  it  often  becomes  necessary  to  first  enlarge  the  dental  arch 
and  force  the  crowns  into  partial  alignment  by  ordinary  means,  prepar- 


THE  SAVING  AND  EXTRACTION  OF  TEETH 


S95 


atory  to  placing  the  incisors  in  the  grasp  of  contouring  forces.  Fig. 
989  shows  the  position  of  the  teeth  in  this  case  in  the  intermediate 
stage,  the  crowns  of  the  incisors  being  forced  forward  to  a  partial 
alignment,  and  with  no  special  facial  improvement.  ( It  may  be  added 
that  at  this  stage  in  the  operation,  cases  of  this  kind  have  been  con- 
sidered finished,  until  it  was  found  possible  to  enlarge  the  apical  arch.) 


lu 


990 


Fig.  991 


Fig.  990  shows  correctly  the  final  result,  which  was  accomplished 
with  the  contouring  apparatus  described  in  Section  ^^I.  It  will  be 
seen  that  the  incisors  are  in  an  upright  position  and  there  is  now  ample 
room  for  all  the  teeth,  while  the  remarkable  improvement  to  the  physi- 
ognomy is  poorly  shown  by  the  face  model  Fig.  991. 

Another  case,  that  of  the  upper  arch,  Fig.  992,  if  examined  alone 
and  compared  with  the  upper  of  the  former  case,  or  Fig.  986,  will   be 


Fig.   992 


found  very  similar.  The  same  crowded  condition  of  the  teeth,  the  same 
lack  of  sufficient  room  for  the  proper  eruption  of  the  canines;  and  yet 
this  is  from  the  model  of  a  case  that  absolutely  demanded  the  extraction 
of  the  premolars.  At  foiu'teen  years  of  age  the  irregularity  presented 
the  appearance  shown  in  the  illustration  Fig.  993,  showing  the  models 
of  the  case  in  occlusion.    The  patient  was  placed  in  charge  of  a  dentist 


890  DENTO-FACIAL  OHTIIOl'KDI A 

who  attempted  the  correction  of  the  irregularity  without  removal  of  the 
first  bicuspids.    Fig.  994  shows  the  result  two  years  afterward. 

It  will  he  seen  that  the  incisors  were  forced  forward  to  a  decided 
labial  inclination,  for  the  purpose  of  crowding  the  canines  into  align- 
ment; and  all  the  anterior  teeth  are  turned  on  their  axes  so  as  to  occupy 
the  least  possible  space.  Fig.  995  is  from  the  model  of  the  face  of  the 
patient  at  that  time. 

That  a  mistake  was  made  in  the  plan  of  tieatment  pursued  is  evi- 
denced by  the  following  considerations:  First,  the  protrusion  of  the 
crowns  of  the  upper  anterior  teeth  produces  an  unhappy  expression 
of  the  mouth  that  is  equivalent  to  a  deformity,  and  one  that  could  not 
be  remedied  in  this  particular  until  certain  members  of  the  dental  arch 
were  removed.  Second,  if  it  were  a  case  in  which  the  maxillary  arch 
was  too  small,  with  a  depression  of  the  overlying  features  of  the  face, 
the  decided  labial   inclination  of  the  teeth  could  be  overcome  by  an 

Fio.   994  Fig.   995 


enlargement  of  the  apical  zone,  which  would  have  permitted  a  slight 
retrusion  of  the  occludal  zone  with  a  partial,  if  not  complete,  regulation 
of  the  dental  and  facial  deformity.  But  this  was  not  the  condition, 
and  therefore  could  not  l)e  considered.  The  third  and  most  efTective 
argument  is  one  which  should  never  be  overlooked  in  all  cases  where 
the  crowns  flare  outward.  The  conical  shape  of  the  teeth  permits  them 
to  stand  in  perfect  alignment,  although  with  a  decided  labial  inclination; 
but  in  this  position  the  interproximate  spaces  so  necessary  to  the  preser- 
vation of  the  teeth  are  so  completely  closed  as  to  cut  off  the  imion  of 
interproximate  gum  tissue,  which  must  ultimately  result  in  the  resorp- 
tion of  the  gum  and  alveolar  process  and  all  the  dire  consequences  that 
follow. 

Had  the  first  premolars  been  extracted,  many  difficulties  in  the  regu- 
lation of  the  teeth  would  have  been  removed;  and  what  is  of  far  greater 
importance,  there  would  have  been  a  satisfactory  result  in  the  dental 
arch  and  physiognomy.     Or  even  further,  had  the  upper  first  premolars 


THE  SAVING  AND  EXTRACTION  OF  TEETH 


<S97 


been  extracted  as  soon  as  they  erupted,  together  with  the  deciduous 
canines,  as  will  be  outlined  in  the  second  phase  of  the  subject,  the  case 
would  have  required  little  or  no  other  treatment. 

Fig.  996  shows    the   present   position   of  teeth  after  regulation,   by 
retruding  the  anterior  teeth  to  fill  spaces  caused  by  the  extraction  of  the 


premolars.  Fig,  997  is  from  a  model  of  the  face  after  treatment.  It  will 
be  seen  that  the  interproximal  spaces  between  the  teeth  are  restored, 
while  the  retrusion  of  the  anterior  teeth  allows  the  lips  to  fall  gracefully 
into  proper  position.  The  improvement  in  the  facial  aspect  of  this  and 
all  other  cases  cannot  be  fully  shown  by  a  plaster  model  of  the  face. 
Fig.  998  was  made  from  a  photograph 
of  this  patient,  taken  a  few  months 
after  the  completion  of  treatment. 

There  are  many  instances  where  the 
early  extraction  of  the  premolars,  as 
soon  as  they  can  be  reached  with  the 
forceps,  is  demanded.  For  example, 
adult  faces  with  decided  protruding 
upper  jaws  and  teeth,  and  with  a 
bulged  appearance  about  the  lower 
portion  of  the  nose.  The  teeth  are 
commonly  large,  prominent,  and 
crowded,  although  not  always  labially 
inclined. 

The  ordinary  upper  protrusions  which  come  under  this  head  are 
so  common  they  will  require  no  further  explanation  or  illustration. 

Upper  protrusions  where  the  teeth  are  not  labially  inclined  are  not 
quite  so  common.  The  alveolar  arch  is  necessarily  prominent,  although 
the  deformity  in  the  main,  as  in  the  more  common  forms  of  protrusion, 
is  due  to  the  large  size  of  the  maxilla  proper,  which  is  far  out  of  pro- 
portion to  the  delicately  chiselled  features  which  it  supports  and  forces 
57 


Fig.   998 

F\^H^H| 

H 

^■^K.      M     ^    j^^BB^^^H 

pp*''" '  '^  %  ^H 

0 

.-H^J^ 

898 


DENTO-FACIAL  ORTHOPEDIA 


into  unsyrametrical  contours.  The  iia.so-lal)i;il  depressions  in  which  the 
wings  of  the  nose  rest  arc  more  or  k^ss  ohHterated,  as  would  he  occa- 
sioned bv  the  sting  of  a  bee  or  an  alveohir  abscess.  '^I'he  nostrils  are 
broad  and  open,  and  the  end  of  the  nose  forced  forward  and  upward 
{retrousse)  by  the  protrusion  of  the  spinous  process  and  cartilaginous 
septum.  The  uj)per  lip,  being  stretched  over  its  inharmonious  frame, 
is  shortened  so  as  to  cover  the  teeth  with  difficulty,  and  in  action  readily 
rises  to  an  unpleasant  exposure  of  the  teeth  and  gums. 

This  is  an  extreme,  although  not  an  uncommon,  condition.  Every  stage 
from  this  to  perfect  harmony  characterizes  the  innumerable  varieties  of 
a  certain  t}^e  of  physiognomy. 

Fig.  999  is  from  the  face  model  of  a  young  man,  aged  eighteen  years, 
and  may  be  taken  as  a  type  of  this  character  of  facial  deformity. 
Fig.  1000  shows  the  teeth  in  occlusion.  The  canines  and  canine  emi- 
nences are  very  prominent,  and  extend  high  up  under  the  wings  of  the 
nose. 

Fig.   9W  Fig.   1000 


Had  this  case  received  the  early  treatment  here  advocated  the 
deformity  would  have  been  prevented,  and  the  almost  insurmountable 
difficulties  attending  its  reduction  during  nearly  three  years  of  constant 
treatment  altogether  avoided. 

Anyone  who  has  never  attempted  to  move  the  roots  of  the  canines 
in  a  posterior  direction  for  patients  older  than  sixteen  years  cannot 
appreciate  the  difficulties  of  such  an  operation.  And  while  the  result 
in  this  case  is  quite  satisfactory  under  the  circumstances,  as  will  be 
seen  by  Figs.  1001  and  1002,  the  physiognomy  is  not  nearly  so  perfect 
esthetically  as  it  would  have  been  had  the  case  received  proper  early 
treatment. 

The  important  consideration  from  a  surgical  and  artistic  standpoint 
in  nearly  all  cases  of  marked  upper  protrusion  is:  Has  not  nature 
been  forced  to  produce  these  conditions,  wholly  or  in  part,  to  accommo- 
date teeth  that  were  too  large  for  the  natural  or  inherent  frame  and 
overlying  features?     And  could  we  have  helped   nature  in  the  early 


THE  HAVING  AND  EXTRACTION  OF  TEETH 


899 


years  of  development  by  making  it  unnecessary  for  her  to  produce  this 
excessive  growth  of  bone  for  the  development  and  sustenance  of  all 
these  large  teeth? 

This  is  true  of  all  protrusions  that  are  caused  by  the  inheritance  of 
inharmoniously  large  jaws  crowded  full  of  teeth. 

We  certainly  cannot  reduce  the  size  of  the  teeth,  but  we  can  reduce 
their  number,  and  in  so  doing  reduce  the  size  of  the  destined  maxillary 
and  dental  arch.  But  we  must  make  no  mistake.  The  danger  of  advo- 
cating such  a  principle  to  those  who  have  given  this  branch  of  dentistry 
little  thought  is  that  teeth  may  be  extracted  to  accommodate  an  over- 
crowded condition  in  the  arch,  with  little  or  no  thought  of  the  physi- 
ognomy, and  too  when  a  careful  and  properly  pursued  study  of  the  features 
and  their  comparison  with  the  parental  types  will  show  that  in  reality 
the  dental  and  maxillary  arch  should  be  enlarged,  and  every  tooth 
of  the  greatest  importance  in  its  development  and  retention. 


Fig.   1001 


Fig.   1002 


How  are  we  to  study  the  undeveloped  face  of  a  child,  every  lineament 
of  which  is  passing  through  rapid  changes  of  growth,  with  a  view  of 
determining  whether  or  not  the  dental  arch  and  jaws  w^U  be  too  prom- 
inent, or  that  other  features  will  not  enlarge  to  a  harmonizing  propor- 
tion ? 

A  most  wonderful  provision  of  nature  in  dentition  causes  the  full- 
sized  crowns  of  teeth  to  erupt,  as  regards  time,  somew^hat  in  proportion 
to  the  natural  growth  and  enlargement  of  the  jaws.  And  even  W'hen 
they  do  not  erupt  earlier  than  is  normal,  or  when  their  natural  eruption 
is  not  interfered  with  by  the  premature  extraction  of  the  deciduous 
teeth,  they  are  .usually  obliged  to  take  an  irregular  position  or  attitude 
at  first,  and  await  the  growth  of  the  jaw^  which  permits  them  to  become 
regular. 

It  is  perhape  a  safe  general  rule  to  never  extract  a  permanent  tooth 
for  the  purpose  alone  of  correcting  a  dental  irregularity,  unless  the  jaw 
has  ceased  ffrowans:;  and  never  then  unless  it  is  shown  by  a  careful  study 


900  DENTO-FACIAL  ORTHOPEDIA 

of  the  position  of  the  teeth — their  rehition  and  occlusion — that  the 
dental  arch  should  not  be  expanded;  or  by  a  study  of  the  physiognomy, 
that  the  alveolo-dental  arch  should  not  be  enlarged? 

In  a  study  of  the  relations  of  the  teeth,  the  jaws,  and  the  physiognomy 
of  a  child  with  the  view  of  determining  the  advisability  of  extraction 
to  correct  or  prevent  the  ultimate  production  of  a  facial  deformity  or 
marked  imperfection  of  the  features,  it  may  become  necessary  to  study 
the  physiognomies  of  both  parents,  and  possibly  other  members  of  the 
family,  to  correctly  determine  the  influence  exerted  by  inheritance. 

In  this  comparison  of  temperament,  physical  frame,  features,  and 
teeth,  it  may  require  no  more  than  a  glance  to  furnish  all  the  data  that 
will  be  of  practical  use. 

Usually  but  one  parent  accompanies  the  litde  patient,  and  a  study  of 
that  one  physiognomy  may  be  a  sufficient  guide;  if  not,  other  members 
of  the  family  should  be  seen. 

If  there  be  a  marked  diflFerence  in  the  parents  it  may  not  be  difficult 
to  determine  from  which  the  child  has  inherited  the  teeth,  by  the  pecu- 
liar shape  and  size  of  the  incisors  alone.  But  in  regard  to  the  maxilhe 
in  an  undeveloped  condition  there  will  be  more  difficulty,  although  it  is 
well  to  remember  that  the  deciduous  teeth  are  rarely  irregular  or  dis- 
proportionate in  size  to  the  frame  and  facial  features.  If,  therefore, 
there  be  a  more  than  natural  difference  in  the  size  of  the  permanent 
and  deciduous  teeth  it  will  indicate  union  of  inharmonious  types. 

In  this  connection  it  must  not  be  forgotten  that  the  crowns  of  the 
permanent  incisors  are  almost  invariably  far  too  large  for  their  undevel- 
oped surroundings.  The  apparently  disproportionate  size  of  the  central 
incisors  to  that  of  the  jaw  is  a  subject  of  frequent  and  anxious  parental 
comment.  If  the  occlusion  of  the  incisor  teeth  be  far  from  a  normal 
t}"pe  in  their  anteroposterior  relations,  and  the  same  condition  exists 
with  either  parent,  it  is  an  indication  of  what  the  child  will  become 
if  unaided  by  dental  skill,  especially  if  a  similarity  be  noted  in  other 
particulars. 

With  differences  in  temperament,  compare  general  shape  and  size  of 
the  eyes,  brows,  ears,  and  teeth. 

Other  features  are  so  subject  to  change  in  the  processes  of  natural 
growth  and  development  that  they  cannot  be  relied  upon  to  furnish 
legitimate  data.  For  instance,  the  nose  may  change  in  a  few  years  of 
late  youthful  development  from  one  originally  small  and  short — and 
over  the  nasal  bones  decidedly  depressed — to  a  form  different  in  every 
particular. 

All  these  things  are  of  the  utmost  importance  in  determining  the 
impropriety  of  extracting  certain  teeth  to  reduce  an  apparent  abnormal 
protrusion,  which  may  in  time  become  symmetrical  in  its  relation  by 
the  natural  growth  of  the  jaws  and  other  features;  and  also  the  equally 
culpable  error  of  saving  teeth,  or  the  failure  to  extract  teeth,  whose 


THE  SAVING  AND  EXTRACTION  OF  TEETH 


901 


very  presence  in  the  arch  obHges  nature  to  reproduce  a  parental  de- 
formity, or  produce  an  acquired  deformity. 

For  a  child  with  a  marked  upper  protrusion  similar  to  Figs.  1003 
and  1004,  with  teeth  prominent  and  crowded  in  an  arch  which  does  not 
admit  of  correcting  by  a  lateral  expansion,  extract  the  first  bicuspids  as 
early  as  possible,  even  before  their  eruption  is  completed,  together  with 
the  deciduous  canines — unless  it  be  one  of  those  very  rare  instances 
where  the  first  permanent  molars  cannot  be  saved. 

The  same  is  true  of  the  lower,  when  there  is  reason  to  believe  there 
will  be  a  disproportionate  overdevelopment  of  the  lower  dental  arch. 

In  the  ordinary  course  of  eruption  the  development  and  eruption  of 
the  permanent  canines  are  doubtless  more  influential  than  those  of 
other  teeth  in  emphasizing  a  protrusion  of  the  central  features  of  the 
physiognomy. 


Fig.   1003 


Fig.   1004 


In  the  course  of  their  eruption  they  are  obliged  to  crowd  into  align- 
ment alone:  the  mesial  surfaces  of  the  roots  and  crowns  of  the  first 
bicuspids — ^which  at  this  time  represent  the  immovable  bases  of  the 
arch — with  the  result  that  the  incisive  and  intermaxillary  portion  of 
the  arch  is  forced  forward  to  a  more  pronounced  position.  This  move- 
ment has  been  shown  to  be  not  impossible  or  difficult  of  attainment  by 
artificial  force,  even  much  later  in  life. 

With  the  first  bicuspids  and  deciduous  canines  removed  sufficiendy 
early  there  are  numberless  instances  when  the  arch,  anterior  to  the 
second  bicuspids,  would  be  diminished  the  width  of  a  bicuspid,  without 
resort  to  artificial  means. 

By  the  exertion  of  a  slight  traction  force  from  an  occipital  base  of 
anchorage  the  sockets  of  the  temporary  canines  will  be  closed  by  the 
permanent  laterals,  and  the  permanent  canines  in  the  course  of  their 
eruption  will  be  deflected  into  the  alveoli  of  the  extracted  bicuspids. 

Figs.  1005  and  1006  represent  one  case  out  of  many  under  treatment 
by  this  method,  although  not  all  by  the  occipital  method,  Fig.  1007  shows 


002 


DENTO-FACIAL  ORTIIOI'EDIA 


the  position  of  the  teeth  after  about  two  months  of  traction  force  from 
molar  anchorages;  the  protrusion  not  beint;  so  j)ronounced  as  to  demand 
the  use  of  the  skull-cap. 

It  will  be  seen  by  the  canine  eminences — although  far  better  shown 
upon  the  model  itself — that  the  position  of  the  canine  crowns  is  imme- 


diately over  the  former  alveoli  of  the  first  bicuspids.  As  they  continue 
to  grow  downward  in  this  somewhat  open  channel,  their  roots,  which 
are  not  at  present  developed,  will  grow  upward,  the  teeth  in  their  entirety 
finally  taking  a  position  and  inclination  similar  to  that  of  the  bicuspids 
which  they  replace,  and  considerably  posterior  to  that  which  they  were 
otherwise  destined  to  occupy. 


Fig.   1007 


The  patient,  aged  nine  years,  had  the  teeth,  eyes,  ears,  and  general 
temperament  of  the  father,  whose  upper  arch  was  abnormally  protruded 
in  a  similar  manner,  which  was  the  raison  d'etre  for  dental  aid. 

Had  the  father's  teeth  been  in  proper  relative  and  symmetrical 
position,  and  similar  to  the  son's  in  other  particulars  which  could  be 
legitimately  used  as  data,  it  would  have  been  an  argument  in  favor  of 


THE  CONTOURING  APPARATUS 


903 


nou-cxtraction  with  tlie  exix'ctatioii  of  otluM-  treatment  later;  but  it  should 
not  have  been  passed  uj)on  without  seeiui;-  the  mother.  Had  the  mother's 
teeth  been  found  small  and  tlie  ocMieral  f)hysical  features  east  in  a  more 
deHeate  mould  than  her  husband's,  investigations  along  other  lines 
would  have  been  required,  with  the  view  of  determining  if  the  child 
had  not  the  large  teeth  of  the  father  associated  with  facial  bones  that 
would  always  be  inharmonious  in  size. 


THE  CONTOURING  APPARATUS 

The  limited  area  upon  which  force  can  be  applied  to  a  tooth,  com- 
pared with  that  portion  covered  by  the  gum  and  embedded  in  a  bony 
socket,  has  made  it  next  to  impossible,  with  all  ordinary  methods,  to 
move  the  apex  of  the  root  in  the  direction  of  the  applied  force;  nor 
could  this  ever  be  accomplished  with  force  exerted  in  the  usual  way  at 
one  point  upon  the  crown,  however  near  the  margin  of  the  gum  it  may 
be  apphed,  for  the  opposing  margin  of  the  alveolar  socket  must  receive 
the  greater  portion  of  this  direct  force,  and  in  proportion  to  its  resist- 
ance it  will  become  a  fulcrum  exerting  a  tendency  to  move  the  apex  of 
the  root  in  the  opposite  direction. 


Fig.   1008 


Fig.   1009 


But  if  in  the  construction  of  the  apparatus  a  static  fulcrum  is  created 
independent  of  the  alveolar  process  at  a  point  near  the  occluding  portion 
of  the  crown,  while  the  power  is  applied  at  a  point  as  far  upon  the  root 
as  the  mechanical  and  other  opportunities  of  the  case  will  permit,  the 
apparatus  becomes  a  lever  of  the  third  kind,  the  power  being  directed 
to  a  movement  of  the  entire  root  in  the  direction  of  the  applied  force. 

This  proposition  is  made  plain  by  reference  to  diagrams.  In  Fig. 
1008  let  A  be  a  point  upon  a  central  incisor  at  which  force  is  applied  in 
the  direction  indicated  by  the  arrow,  then  the  opposing  wall,  B,  of  the 
alveolar  socket  near  its  margin  will  receive  nearly  all  of  the  direct  force; 
and  in  proportion  to  its  resistance  there  will  be  a  tendency  to  move  the 
root  in  the  opposite  direction.  This  will  also  hold  good  even  if  the 
force  be  applied  at  A,  Fig.  1009,  or  as  far  upon  the  root  as  may  be  per- 
mitted by  attaching  a  rigid  upright  bar,  C,  to  the  anterior  surface  of  the 


904 


DRNTO-FACIAL  OltT/fOPEDI A 


crown;  the  only  diii'erence  bein^  that  the  direct  force  is  distributed 
over  a  greater  area.  But  if,  as  in  Fig.  1010,  to  the  h)wer  end  of  C  a 
traction  wire  or  bar,  F,  is  attached,  and  if  the  mechanical  principles  of 


Fi<;.    1010 


the  machine  be  further  enforced  by  uniting  its  posterior  attachment  to 
the  anchorage  of  the  power  bar  P,  the  anchorage  force  will  be  materially 


Fig.   1011 


neutralized  and  an  independent  static  fulcrum  at  D  created.  The 
apparatus  now  will  distribute  its  force  over  the  entire  root,  and  give 
complete  direction  and  control  of  whatever  power  is  put  into  it.    The 


THE  CONTOURING  APPARATUS  905 

entire  tooth  niay  he  carried  forward  Ixxhly  or  either  end  may  he  made 
to  move  the  more  rapidly.  Tiie  force  thus  directed  to  the  ends  of  the 
roots  will  have  an  increased  tendency  to  move  the  more  or  less  yielding 
bone  in  which  they  are  embedded. 

For  practical  illustrations  of  what  has  been  accomplished  by  an 
apparatus  of  this  kind  in  moving  the  upper  labial  teeth  forward  bodily, 
see  cases  described  in  Sections  I,  IV,  and  V. 

As  nearly  all  irregularities  of  this  class  demand  a  protruding  movement 
of  the  upper  labial  teefli,  with  the  view  of  carrying  forward  with  the  roots 
the  labial  alveolar  ridge  and  incisive  process,  it  is  of  the  greatest  impor- 
tance that  every  detail  in  the  modern  construction  and  application  of 
the  only  apparatus  calculated  to  effectively  perform  this  work  should  be 
fully  understood,  as  upon  this  will  largely  depend  the  real  success  of  the 
operation. 

The  drawing  represents  the  regular  protruding  contour  apparatus, 
adapted  for  all  pronounced  cases  of  this  class  in  which  a  considerable 
bodily  protruding  movement  of  the  upper  labial  teeth  is  demanded. 
The  scientific  principles  of  movement  accomplished  by  this  apparatus 
have  been  fully  explained.  In  this  apparatus  the  power  bow  is  No.  13 
extra  hard  German  silver.  The  rootwise  bar  attachments  on  the  incisor 
bands  are  also  cut  from  the  same  size  of  wire,  and  are  formed  to  receive 
the  force  of  the  bow  above  the  gingival  borders. i 

Provision  should  always  be  made  for  the  attachment  of  the  intermax- 
illary elastics  at  the  distal  extremities  of  the  anchorages.  If  the  second 
molars  have  erupted,  these  teeth  should  be  joined  to  the  anchorages 
for  the  attachment  of  the  buccal  hooks  as  shown.  Otherwise,  the  elastic 
bands  are  looped  over  the  distal  ends  of  the  fulcrum  tubes. 

The  teeth  should  be  properly  separated,  and  each  finished  band 
and  anchorage  so  perfectly  fitted  that  it  can  be  easily  forced  on  and 
off  with  the  aid  of  a  wood  plugger  and  band  removing  pliers,^  to 
make  slight  but  necessary  changes  in  the  shape  or  position  of  the 
attachments  or  power  bow.  The  power  bows  for  extensive  move- 
ments are  always  No.  13  extra  hard.  They  should  be  bent,  first 
upon  the  model  and  finally  at  the  chair,  to  conform  to  the  shape 
of  the  arch,  and  their  ends  to  lie  evenly  in  the  power  tubes  without 
the  slightest  tension.  In  the  final  moves  of  this  important  requirement, 
place  the  anchorages  in  position  and  the  power  bow  with  the  threaded 
ends  lying  along  the  outside  of  the  tubes.  Then  place  the  right  end  in 
its  tube  and  see  that  the  other  lies  exactly  parallel  with  the  left  tube  and 
in  proper  shape  and  position  in  front.  Then  place  the  left  end  in  its 
tube  with  the  other  end  free,  and  go  through  the  same  movements. 

1  For  the  construction  of  the  anchorages,  see  Stationary  Anchorages,  Chapter  VII, 
Dental  Orthopedia,  and  then  turn  to  B.  91  for  directions  in  placing  and  soldering 
the  fulcrum  and  power  tubes. 

2  Ibid. 


900 


DENTO  FACIA L  ORTIIO/'EDIA 


This  mav  ro(|iiiro  rcj)catiii<^'  severul  tiiiics,  with  the  <i;ivute.st  nicety  of 
)U(i<,niieiit  and  patience  in  detail,  before  you  are  able  to  assemble  the 
bow  and  anchora^^es  j)roj)erly  to<,^ether.  The  heavy  bending  pliers, 
Fig.  1012,  are  indispensable  for  this  operation. 

In  assembling  the  power  bow  with  the  anchorages,  after  it  has  been 
properly  shaped,  insert  one  end  in  its  tube  with  the  anchorage  in  place, 
then  slip  the  tube  of  the  other  anchorage  on  to  the  free  end  of  the  bow  and 
force  it  to  place  on  the  teeth.  These  movements  should  be  observed 
in  the  final  cementing  of  the  anchorages,  as  it  would  be  impossible  to 
place  the  rigid  bar  otherwise.  In  the  preliminary  assembling  after  the 
anchorages  and  bow  are  properly  placed,  the  labial  bands  which  have 
been  previously  fitted  to  the  teeth  are  placed  in  position,  with  their 
rootwise  extensions  resting  over  the  bow.  It  may  be  found  at  this  time 
that  the  bow  will  re(|uire  lifting  or  lowering  slightly  by  bending  it  at 
the  sides  while  in  position,  to  bring  it  to  the  exact  position  to  be  cla.sped 


Fir,.    1012 


by  the  extensions.  The  latter  will  also  usually  require  bending  and 
filing  to  fit  them  to  the  recjuirements  of  the  bow.  The  ends  are  filed 
on  the  gingival  side  to  a  flattened  taper,  which  should  extend  a  trifle 
beyond  the  bow  with  a  slight  lingual  curve,  to  aid  them  in  retaining 
their  position  under  tension. 

In  the  shaping  and  fitting  of  the  rootwise  attachment  and  bow,  the 
greatest  care  and  consideration  should  be  exercised.  First,  the  bands 
for  extensive  movements  should  extend  nearly  to  the  highest  gingival 
border  of  the  gum,  and  from  that  point  the  rootwise  extensions  should 
bend  forward  so  as  to  freely  clear  the  borders  of  the  gum,  and  then 
back  to  a  position  to  slightly  overlap  the  power  bow\ 

The  difficulty  of  bending  the  rigid  extensions  to  a  sharp  angle,  if 
necessary,  without  injury  to  their  band  attachments,  may  l)e  overcome 
by  using  the  special  pliers  shown  in  Fig.  1018,  which  is  made  to  clasp  the 
band  and  its  attachment  firmly,  w^iile  the  extension  is  given  the  desired 
shape  with  pliers  and  file.    Second,  the  power  bow  should  rest  slightly 


THE  CONTOURING  APPARATUS 


9(J7 


above  the  highest  inar>>'iiial  points  of  the  central  ineisors  and,  in  the  final 
fitting,  conform  to  the  shape  of  the  gum,  hut  freely  clear  its  surfaces. 
This  is  very  important  as  the  natural  swelling  of  the  gums  in  the  oper- 
ative action  will  be  greatly  increased  by  any  undue  pressure  of  the  bow. 
Should  this  be  found  to  be  a  fact  at  any  time  during  the  operation  the 
labial  bands  should  be  removed,  and  the  extensions,  upon  which  the 
relative  position  of  the  bow  to  the  gum  depends,  should  be  bent  forward 
so  as  to  free  the  bow  from  its  embedment  in  the  swollen  gum.  Third, 
in  the  original  shaping  of  an  upper  power  bow  it  will  be  usually  advis- 
able to  curve  it  downward  at  the  median  point  to  prevent  it  from  inter- 
fering with  the  free  action  of  the  frenum. 

Before  removing  the  temporarily  assembled  apparatus,  the  bow 
should  be  marked  on  each  side  of  the  respective  rootwise  extensions, 
for  guide  markings  to  cut  tiie  square  grooves,  shown  by  the  drawing, 
in  which  the  extensions  rest  while  in  action.    In  the  final  cementing  of 

Fig.   1013 


the  labial  bands,  they  are  simply  carried  to  their  respective  positions 
on  the  teeth  and  bow.  The  fitting  and  placing  of  the  fulcrum  bow 
No.  22  is  the  same  as  for  the  small  alignment  bows  which  are  threaded 
at  one  end. 

Treatment  Adjustments. — In  applying  the  force  which  is  to  follow  the 
first  conscious  tension  of  the  nuts,  the  large  nuts  of  the  power  bow  should 
be  given  about  two  quarter  turns  three  times  a  week.  As  the  movement 
advances  it  will  become  necessary  to  unscrew  the  fulcrum  nut  occasion- 
ally to  allow  the  incisal  zone  to  move  forward  with  the  roots.  If  the  roots 
are  found  to  be  moving  dangerously  fast  for  the  safety  of  their  vitality,  the 
application  of  force  should  be  stopped  in  the  power  bow,  and  if  necessary 
the  nuts  may  be  unscrewed  slightly.  Unscrewing  the  nut  upon  the 
fulcrum  bow  is  also  equivalent  to  reducing  the  force  upon  the  roots.  It 
may  be  advisable  to  cut  and  remove  the  fulcrum  bow  entirely,  to  be 
replaced  with  a  new  one  when  the  danger  is  past.    The  danger  line  will 


908  DENTO-FACIAL  ORTIJOPEDIA 

be  indicated  by  umisiial  sensitiveness  to  heat  and  cold  over  the  root 
or  roots  of  the  affected  teeth,  which  shonld  not  l)e  allowed  to  arrive  to 
a  continual  pain.  Perfect  rest  should  be  afforded  to  the  teeth  and  the 
pum  painted  with  strong  tincture  of  iodin,  two  or  three  times  a  week, 
until  all  irritation  subsides. 

Those  who  have  followed  closely  the  directions  will  realize  something 
of  the  difficulties  and  skill  necessary  for  the  perfect  accomplishment 
of  bodily  moving  the  labial  teeth  for  the  correction  of  facial  contours. 
The  author  wishes  to  say  that  unless  the  operation  is  considered  of 
sufficient  importance  to  give  to  it  the  same  painstaking  skill  that  is  de- 
manded in  other  })ranches  of  dentistry,  it  had  better  not  be  attempted, 
as  in  all  probability  it  will  prove  a  failure.  This  refers  not  alone  to  the 
construction  and  application  of  the  regulating  apparatus,  but  to  the 
construction  and  attachment  of  the  proper  retaining  appliance  that  is 
intended  to  permanently  sustain  the  position  gained.  On  the  other 
hand  the  truly  wonderful  work  which  this  single  apparatus  has  accom- 
plished in  the  author's  hands,  attested  now  by  hundreds  of  cases,  proves 
to  him  that  its  work  in  other  hands  will  cause  this  principle  to  live  and 
grow  in  favor. 

Fifi.   1014 


An  apparatus  for  retruding  the  roots  of  the  anterior  teeth  is  con- 
structed in  a  very  similar  manner  (Fig.  1014).  The  direction  of  the  two 
forces  being  reversed,  it  becomes  necessary,  however,  to  make  certain 
important  variations.  The  power  bow  P,  now  exerting  a  traction  force. 
No.  16  will  be  found  sufficiently  large  for  all  purposes.  It  is  not 
flattened,  but  rests  in  grooves  cut  in  the  anterior  surfaces  of  the  upright 
bars  B.  The  power-bow  tu})es  should  be  soldered  closely  to  the  anchor- 
age bands,  so  that  the  nuts  which  now  work  at  the  posterior  ends  of  the 
bow  will  not  irritate  the  mucous  membrane  of  the  cheek.  The  fulcrum 
bow  F,  exerting  in  this  apparatus  a  jack-screw  force,  should  also  be 
No.  16.  It  is  flattened  along  its  middle  portion  to  engage  with  the 
occluding  ends  of  the  upright  bars  at  D,  provision  being  made  for  the 
purpose  in  the  construction. 

The  power  of  the  two  forces  being  so  great  upon  the  upright  bars, 
with  a  tendency  to  lift  the  occluding  ends  from  their  attachments,  and 
thus  allow  the  free  ends  to  press  into  the  gum,  it  is  important  with  this 


THE  CONTOURING  APPARATUS 


909 


apparatus  that  the  occluding  end  attachments  be  reinforced  by  soldering 
to  the  bands  an  extra  piece  of  banding  material  that  shall  extend  from 
the  labial  face  over  the  occluding  end  of  the  tooth  to  the  lingual  portion 
(Fig.  1015). 

After  the  joint  of  the  band  has  been  soldered,  the  reinforcing  piece, 
of  sufficient  length  for  the  purpose,  should  be  soldered  to  the  labial 


Fig.    1015 


face  alongside  of  the  joint;  then  the  band  is  perfectly  fitted  to  the  natural 
tooth — the  extra  piece  being  bent  over  and  burnished  to  its  position 
on  the  labial  surface,  and  the  position  of  its  end  distinctly  marked  upon 
the  band,  to  serve  as  a  guide  to  soldering. 

When  the  hoods  are  completed  in  this  way  and  finally  all  placed  on 
the  tooth  and  perfectly  fitted,  an  impression  should  be  taken  for  fitting 
and  soldering  the  upright  bars  as  described  for  the  protrusion  apparatus. 


CHAPTER    XXIII 

ORAL  PROPHYLAXIS 

By  S.  H.  GUILFORD,  A.M.,  D.D.S.,  Ph.D. 

When  it  is  remembered  that  the  mouth  is  the  principal  vestibule 
lea(lin<ii;  to  the  internal  organs;  that  through  it  must  pass  all  of  the  aliment 
designed  to  promote  and  sustain  bodily  function;  that  into  it  the  various 
salivary  glands  pour  their  secretions,  which  become  mingled  with  the 
food  and  then  pass  on  to  take  part  in  the  process  of  digestion,  it  becomes 
apparent  that  this  important  cavity  should  at  all  times  be  kept  in  a 
thoroughly  pure  and  healthy  condition  in  order  that  what  passes  through 
it  may  not  l)e  contaminated. 

All  saliva  carries  with  it  in  solution  an  amount  of  calcium  salts  which 
may  attach  itself  to  the  tooth  surfaces  and  afford  a  favorable  opportunity 
for  the  lodgement  and  retention  of  minute  food  particles,  which,  if  allowed 
to  remain,  undergo  putrefactive  decomposition,  causing  serious  injury  to 
tooth  substance. 

Li  addition,  the  deposit  furnishes  a  hal)itat  for  various  forms  of  bac- 
teria, which,  passing  into  the  stomach,  may  interfere  with  the  process 
of  digestion,  or  their  toxins  may  produce  pathological  conditions  which 
will,  to  a  greater  or  less  degree,  afl'ect  the  health  of  the  individual. 

Oral  prophylaxis  is  that  branch  of  dental  science  which  has  for  its 
object  the  maintenance  of  a  clean  and  healthy  condition  of  the  oral 
cavity.  This  can  be  brought  about  only  by  the  skilful  and  conscientious 
service  of  the  dental  practitioner  conjoined  with  the  utmost  care  and 
diligent  co5peration  on  the  part  of  the  patient. 

^Yhile  it  has  long  been  known  that  caries  of  the  teeth  could  be  greatly 
minimized  and  largely  prevented  by  the  careful  and  frequent  removal  of 
foreign  deposits  and  accumulations  from  and  between  the  teeth,  it  is 
only  recently  that  the  profession  and  the  laity  have  awakened  to  the  fact 
that  the  oral  cavity  could  be  so  carefully  kept  as  always  to  be  in  a  healthy 
condition,  and  that  when  in  this  condition  many  ills  hitherto  unaccounted 
for  would  be  prevented. 

Once  the  dental  practitioner  felt  that  his  duty  was  performed  when 
he  had  removed  the  most  visible  deposits  found  upon  the  teeth  whenever 
the  patient  happened  to  presetit  for  other  service,  adding,  perhaps,  a 
word  of  advice  as  to  the  more  frecjuent  use  of  brush  and  powder.  No 
effort  was  made  to  impress  upon  the  patient  the  value  of  this  personal 
care  other  than  that  it  woukl  measurably  prevent  future  caries,  neither 
(910) 


ORAL  PROI'IIYLAXIS  911 

was  he  urofed  to  present  himself  at  frecjiient  and  fixed  intervals  for 
inspection  and  professional  assistance  in  the  way  of  prophylactic  treat- 
ment. 

Now,  in  the  light  of  fuller  knowledge,  the  practitioner  has  come  to 
regard  himself  as  the  custodian  of  the  patient's  mouth,  and  feels  it  to  be 
part  of  his  professional  duty  to  fully  explain  the  importance  of  oral 
hygiene  and  emphasize  the  necessity  for  constant  watchfulness  and 
care  if  the  dental  organs  are  to  be  preserved  for  a  lengthened  term  of 
years  and  the  general  system  measurably  protected  from  the  disturbing 
influence  of  pathogenic  organisms. 

A^'hen  the  patient  has  once  been  fully  impressed  with  the  necessity 
for  unremitting  care  on  his  part,  and  the  importance  of  periodic  visits 
to  the  dentist,  the  foundation  will  have  been  laid  for  the  best  results  that 
oral  prophylaxis  can  accomplish. 

In  beginning  the  treatment  for  a  patient,  the  first  requirement  is  that 
the  teeth  be  carefully  examined,  and  then  by  proper  instrumentation 
freed  from  all  hard  deposits  found  upon  any  of  the  exposed  surfaces  of 
the  crowns  and  also  from  the  lesser  deposits  that  often  lie  beneath  and 
are  concealed  bv  the  free  margin  of  the  gum. 

So  carefully  should  this  part  of  the  operation  be  performed,  that  when 
completed  no  calcareous  matter  may  remain  anywhere  upon  the  teeth. 
Next,  the  labial,  lingual,  and  buccal  surfaces  should  be  gone  over  and 
further  cleaned  with  orange-wood  stick  and  pumice,  rigorously  applied. 
This  will  not  only  remove  any  minute  portions  of  ordinary  foreign  matter, 
but  also  such  gelatinous  plaques  or  accumulations  of  inspissated  mucus 
as  are  most  generally  present.  After  this  the  stick  and  pumice  should  be 
used  upon  such  portions  of  the  approximal  surface  as  can  be  reached 
by  them,  and  finally  floss  silk,  charged  with  pumice,  should  be  passed  to 
and  fro  between  the  teeth  to  cleanse  and  polish  thoroughly  the  surfaces 
most  nearly  in  contact.  In  this  manner  every  part  of  each  tooth  surface 
W'ill  receive  thorough  treatment. 

The  pumice  used  should  be  of  the  fine  variety  known  as  pumice  flour, 
and  if  incorporated  into  a  pasty  mass  with  glycerin  it  wdll  adhere  better 
to  the  stick  and  floss  and  render  more  efficient  service. 

This  cleansing  of  the  teeth  cannot  be  done  thoroughly  if  done  hastily. 
The  operation  must  be  carried  forward  with  a  fair  amount  of  delibera- 
tion, so  that  no  single  feature  of  it  may  be  overlooked.  If  the  case  in 
hand  is  one  that  bears  evidence  of  long  neglect,  two  or  three  hours' 
time  may  have  to  be  spent  upon  it  in  order  to  bring  about  a  proper 
condition  of  cleanliness.  In  many  cases  it  will  be  well  to  divide  the 
operation  betAveen  several  sittings  in  order  to  avoid  undue  nerve-strain 
or  suft'ering  on  the  part  of  the  patient. 

When  once  completed  the  patient  should  be  given  to  understand  that 
this  first  operation,  while  placing  the  mouth  in  a  hygienic  condition,  is 
but  the  beginning  of  the  treatment,  and  that  it  will  have  to  be  followed 


(J  12  ORAL   I'ROPHYLAXIS 

up  by  successive  treatments  of  a  similar  but  much  milder  character  at 
intervals  of  a  month  or  two;  the  frequency  of  the  treatments  depends 
laro-ely  upon  the  faithfulness  of  the  patient  in  his  personal  care  of  the 
teeth  during  the  intervals. 

As  to  the  patient's  part  in  furthering  the  prophylactic  treatment,  he 
should  be  instructed  to  brush  his  teeth  carefully  immediately  upon 
arising,  after  each  meal,  and  again  before  retiring.  At  least  once  a  day, 
at  one  of  the  brushings,  a  dentifrice  should  be  used  to  supply  the  necessary 
friction  which  the  brush  alone  would  not  provide.  Dental  floss  muot  also 
be  passed  between  all  of  the  teeth  after  they  have  been  brushed,  and  at 
any  intermediate  times  when  food  has  been  taken. 

it  should  be  made  plain  that  all  the  details  of  treatment  must  be 
conscientiously  carried  out  both  by  patient  and  operator  if  success  is 
looked  for,  and  the  patient  may  be  assured  that  by  faithfully  complying 
with  the  regulations  laid  down  not  only  will  his  mouth  be  kept  in  a 
thoroughly  hygienic  condition  and  decay  of  the  teeth  controlled,  but 
that  recession  of  the  gums  and  inflammation  and  destruction  of  the 
subjacent  tissues  about  the  roots  of  the  teeth  will  be  largely  and  often 
entirely  prevented. 

One  of  the  main  contributing  causes  to  success  in  oral  prophylaxis 
lies  in  awakening  in  the  patient's  mind  the  necessity  for  the  elaborate 
and  persistent  treatment  proposed. 

As  prophylaxis  of  the  oral  cavity  is  still  a  novel  idea  to  the  laity,  and 
thev  are  likely  to  confound  it  with  the  old  and  simple  operation  of 
cleaning  or  cleansing  the  teeth,  patients  may  fail  to  realize  the  necessity 
for  the  many  visits  to  the  office  and  the  increased  cost  of  the  frequent 
treatments. 

For  this  reason  it  is  necessary  for  the  operator,  if  he  wishes  to  achieve 
the  best  results  of  treatment,  constantly  to  hold  before  the  patient  the 
advantages  that  are  sure  to  accrue  from  faithful  and  continued  treat- 
ment and  the  dire  results  that  are  certain  to  result  either  from  neglect 
or  interrupted  service. 

Unless  the  interest  of  the  patient  is  aroused  to  the  extent  of  making 
him  a  convert  to  the  gospel  of  mouth  cleanliness,  coupled  with  the  fear 
of  early  loss  of  the  teeth  when  treatment  is  neglected,  we  can  hardly 
hope  for  success  in  our  efforts. 

A  patient  must  either  be  won  over  to  our  views  in  the  beginning  or  he 
will  discontinue  the  treatment  after  a  few  visits  and  fail  to  realize  the 
intended  benefit.  Patients  afflicted  with  pyorrhea  and  its  accompani- 
ments of  pain  and  loosening  of  the  teeth  are  usually  very  willing  to 
undergo  a  course  of  prophylactic  treatment  in  the  hope  of  obtaining 
relief;  but  those  whose  dental  organs  and  oral  tissues  have  given  them 
no  perceptible  trouble  are  not  so  easily  converted  to  the  importance  of 
prophylaxis  as  a  preventive  measure. 

The  advantages  to  be  derived  from  systematic  prophylactic  treatment 


ORAL  PROPHYLAXIS  913 

may  bo  sunimarizcd  and  presented  to  patients  in  some  sncli  form  as  the 
following;; 

1.  The  oral  eavity  will  be  kept  in  a  thoroughly  clean  and  sanitary 
condition. 

2.  The  breath  will  be  free  from  oflensive  odors. 

3.  Dental  caries  will  be  largely  prevented  by  the  removal  of  those 
active  agents  which  are  mostly  responsible  for  it. 

4.  Extensive  caries  cannot  occur  because  the  frequent  examinations 
will  disclose  the  very  beginnings  of  tooth  injury. 

5.  (xum  recession  and  root  exposure  will  be  delayed  or  prevented 
by  the  sanitary  condition  prevailing  and  by  the  gentle  stimulation  of 
the  gum  tissue  induced  by  the  frictional  treatment. 

(i.  In  like  manner  the  irritation  caused  by  calcareous  deposits  at  or 
beneath  the  gum  which  promote,  if  they  do  not  really  produce,  pyorrhea 
will  be  eliminated. 

7.  By  preventing  gum  irritation  and  controlling  pyorrheal  tendencies 
the  teeth  should  remain  firm  and  useful  to  advanced  age. 

8.  With  the  oral  cavity  kept  relatively  free  from  pathogenic  organisms, 
and  foreign  substances  undergoing  putrefactive  decomposition,  the 
digestive  functions  will  be  less  likely  to  be  unfavorably  influenced,  and 
the  entire  system  will  be  better  in  consequence.  ^ 


58 


INDEX 


Absi'kss,    ;m'iiIc,    apical,     facial    swrlliiijr 
ftoni,  44.) 
.sccoiul  stage  of,  441 

Ireatment,    surgi- 
cal,  442 
therajieutir, 
442 
thinl  sfagc  of,  443 

troatment,     surgi- 
cal. 443 
therapeutic, 
444 
Ireatment  in  sjphilitics,  441 
alveolar,  blootl  poisoning  due  to,  124 

in  deciduous  teeth,  681 
apical,  pathology  of,  428 
around  third  molar,  diagnosis,  439 
bone  caries  and  necrosis  due  to,  453 

sinus  in,  439 
chronic  apical,   amputation   of  root 
apex,  449 
calculus,  452 
diagnosis     h\    radiograph, 

449 
replantation  in,  450 
root   canal  filling  methods, 
X  449 

in  deciduous  teeth, 
462 
rubbi-r  cups  for  gums,  449 
systemic        complications, 
'  treatment,  452 
treatment,  446 

when    discharging 

through  fistula,  447 

\vhen    discharging 

through   root   canal, 

446 

in   encvstment  of  pus, 

452  ' 
recurrent  cases,  44 1 
dento-alveolar,  causes,  432 
diagnosis,  438 
infection  of  meninges  of  brain, 

569 
morbid  anatomy  of,  433. 
predisposition  to,  437 
systemic  intoxication  from,  438, 

445 
subacute,  436 

tests  for  vitality  of  tooth,  439 
treatment,  440 


yVbsccss,  d('iil()-al\  eolai',  I  real iiicnl ,  open- 
ing l)ulp  cliamhcr,  4  10 
rubber  dam  guard,  441 
Iherapeut  ic  agents,  441 
ways  of  discharge,  435 
involving  antrum,  439,  451 
paths  of  discharge,  439 
pericemental,  in  pyorrhea,  5(J1 

due  to  pyorrhea,  diagnosis,  438 
syringe,  443. 
Abscesses  on  deciduous  teeth,  453 
Absorbent  paper,  138 
Actinomvces,     infection     through    ])ulp, 

123      " 
Adrenalin  in  local  anesthesia.     See  Anes- 
thesia. 
Air  syringe,  138 
Alloy  and  cement  fillings,  331 
Alloys,  262.     Sec  also  Amalgams, 
annealing,  270 
effects,  271 
Black's,  264 
buying  and  keeping,  289 
crushing  resistance,   272 
Flagg's,  266 
silver-tin,   exhibit,   com]josi(iou  and 

physical  properties,  265 
strength,  272 
Townsend's,  266 
Alveolar  necrosis,  treatment,  453 
process,  59 

changes  following  tooth  move- 
ment, 733 
development,  58 
growth,  108 
in  orthodontia,  726 
peridental  membrane,  102 
resorption,  562 
surgical  anatomy,  561 
Amalgam,    Black's    formula,    264.     See 
also  Alloys, 
carriers  and  pluggers,  284 
Arthur's,  284 
Ivory's,  285 
cavity  preparation,  277 
cement  fillings  and,  326 
classification,  289 
comparative  behavior,  291 
constituents,  266 
contraction  and  expansion,  268,  293 

measuring,  294 
copper,  278 

fillings,  cavity  lining,  323 
heatine:  spoon  for,  288 

(915) 


916 


INDEX 


Anuilgiun,     roppor,     ]\irk'.s      elect  loly  lie 
lirepanitioii,  2<SS 
Fonchcr.s  .studies  on,  2()7 
fillings,  ccinent  lining  under,  ;^2S 
change  in  buli<,  293 
discoloration  of  tooth  tissue,  292 
finishing,  284 
versus  gold  fillings,  32.5 
niatriees  in,  254 
repairing,  233 
Flagg's,  292 
flow  of,  274 
gold  fillings  and,  329 
indications  for,  277 
inlays,  327,  331 
matrix  in  filling,  284 
mercury,  amount  in  mixing,  280 

effect  on  cru.shing  resistance,  274 

on  flow,  27.5 
empirical    methods    of    mixing 
alloy  and  mercury,  287 
micrometers,  294 
mixing,  279 

mortar  for,  280,  287 
nature,  262 

crystallization,  264 
diffusion,  264 
packing,  282 

pluggers  for  packing,  282 
Arthur's,  285 
Black's,  282 
Ivory's,  283 
rapid  setting,  278,  291 
repairing,  233 
selection,  277,  289 
slow  .setting,  278,  291 
thermal  and  chemical  relations,  276 
tin  foil  fillings  and,  321 
use  and  manipulation,  277 
washing,  287 
Ameloblasts,  63 
Amputation  of  root  apex,  449 
Analgesia,  dentinal  by  cocain,  148 
Anchorage  in  orthodontia,  764 
Anesthesia,  general,  chloroform,  150 
dentin,  sensitive,  150 
discrimination  in  use,  611 
ether,  613 
examination   of   joatient   before 

administration,  611 
indications  for,  611 
mouth  props,  559 
nitrous  oxid,  618 

apparatus,  618 
Hewitt's  method,  619 
and  oxygen,  619 
preparation  of  patient,  612 
selection  of  anesthetic,  612 
somnoform,  150 
local,  623. 

active    principle    of    suprarenal 
capsule    and    synthetic    sub- 
stitute, 628 
adrenalin,  629 
anemia,  local,  626 
anterior  teeth,  single,  645 
cocain,  630 

antidotes,  631 


Anesthesia,  local,  cocain  solutions,  ()31 
substitutes,  ()32 
t()xi(!  syiiii)toms,  ()30 
cocain-adrenalin    injection,    404 
contraindication  of  injection   in 

oral  disease,  638 
cysts,  645 
dentin,  642 
diploic,  404 
ethyl  chlorid,  627 

mode    of    api)li('ation, 
628 
freezing  mixtures,  627 
history,  ()23 
hypodermic  .syringes,  634 

manner  of  keeping,  636 
hypodermic  needles,  636 
means  of  producing,  624 
novocain,  633 

advantages,  632 
dosage,  633 
dropping  bottle,  634 
low  toxicity,  633 
operations     about     the    mouth 

other  than  extraction,  644 
osmotic  pressure,  625 
palate,  hard  and  soft,  645 
physiological    action    of    anes- 
thetics, 625 
planting  teeth,  657 
pressure,  642 

pulp,  642.    See  also  Pulp  Anes- 
thesia, 
suprarenin,  630 

teeth  and  roots,  several  simul- 
taneously, 639 
one-half  of  lower  jaw, 
640 
of  upper  jaw,  639 
single  and  diseased,  638 
technic}ue  of  injection,  636 

conductive     mandibu- 
lar, 641 
intra-osseous,  639 
peridental,  638 
perineurial,  639 
into  pulp,  642 
rhomboid   infiltration 

for  tumors,  644 
subperiosteal,  637 
tongue  and  floor  of  mouth,  645 
tumors,  644 
}>artial  by  ether,  150 
Angina,  Vincent's,  differential  diagnosis 

from  pyorrhea,  .500 
Angle's  orthodontia,  683 
Antisepsis  in  dentistry,  118 

prevention  of  tuberculosis,  125 
Antiseptics,  comparative  list,  128 

definition,  12S 
Antrum  of  Highmore,  empyema,  439 

fistula  treatment,  451 
Apes,  tooth  forms  in,  24,  30 
.Vrchcs,  dent.'il  and  maxillary,  contracted, 
889 
effect  on  tooth  development,  722 
forces  proflucing  abnormal  develop- 
ment, 835 


INDEX 


017 


Arches,  iini)ort;incc  in  oc^clusion,  094 
main  types,  19 
roundctl,  20 
square,  20 
V,  20 
square,  19 
Arsenic.'    See  also  I'ulp  devitalizalion. 
in  cements,  301 

in    devitalizing    i)ulps    of    deciduous 
teeth,  078 
Arsenical    applications,    accidents    from, 
408 
necrosis,  antidote,  408 
paste  for  pulp  devitalization,  405 
Ai'ticulation,  normal,  21 
Atavism,  law  of,  54 
Auto-infection  in  mouth,  123 


B 


Bacteria,    oral,    isolation    for    making 

vaccines,  511 
Bands    in    orthodontia,    making    plain, 

759 
Bicuspid,  evolution  of  form,  18 
lower  first,  37 
second,  39 
odontography,  23,  35 
second,  anatomical  considerations  in 

extracting,  567 
upper  first,  35 
second,  37 
Bismuth  paste  in  pyorrhea,  503 
Bleaching  teeth,  524 
agents  for,  525 
cataphoresis,  539 
drugs  used,  540 

Hollingsworth's  apparatus,   540 
chemical  considerations,  525 
chlorin,  526 

filling  pulp  chamber,  532 
final  washing  of  tooth,  532 
instruments,  531 
manner  of  keeping  drug,  531 
Truman's  method,  531 
Wright's  method,  533 
chlorinated  soda,  533 
hydrogen  dioxid,  534 

Harlan's  method,  536 
McQuillen's  method,  536 
Schreier's     kalium-natrium 

paste,  536 
technique,  634 
and  aluminum  chlorid  (Harlan), 

536 
and  electric  light,  542 
indications  for,  524 
iodin,  534 
light,  542 
perhj-drol,  535 
preparation  of  teeth  for,  527 
pyrozone,  535 
removal  of  old  fillings,  530 
root  canal  filling,  529 
saponification  of  root  canal  contents, 

530 
sodium  dioxid,  536 


Hlea(;hing  sodium  dioxid,  special  indica- 
tion in  i)utrescent  cases,  538 
stains,  special,  542 

metallic  salts,  542 
Bone,  caries  and  necrosis  due  to  abscess, 
453 
growth  during  retention,  799 
in  tooth  movement,  726 
Bonwill's  "law"  of  occlusion,  693 
Brachycephalic   peoples,    type   of  dental 

arch  in,  20 
Brain,   inflammation  of  meninges  from 

suppurating  tooth,  569 
Bridge-work  as  a  source  of  infection,  124 
Broaches,  Donaldson's,  413 
Kerr's,  413 

for  root  canal  work,  459 
sterilization,  120 
Brushing  children's  teeth,  682 
Burs,    Boley   micromillimeter  gauge   for 
ordering,  163 
for  cavity  preparation,  163 
dentate,  163 
finishing,  228 
fissure,  use  of,  171 


Calculus  in  chronic  apical  abscess,  452 
See  also  Tartar, 
salivary,  chemical  nature  of,  474 

as  predisposing  cause  of  pyor- 
rhea. See  Pyorrhea  alveolaris. 
serumal,  nature  of,  474 
Camphor,  tincture,  for  nausea,  200 
Canada  balsam  for  root  canal  filling,  458 
Candy,  effect  on  deciduous  teeth,  682 
Canine  tooth,  extracting  impacted,  588, 
597 
lower,  30,  32 
odontography,  23,  30 
Carbolic  acid  for  cavity  lining,  151 

for  sensitive  dentin,  151 
Caries,  action  on  enamel  rods,  62 

in  deciduous  teeth,  silver  nitrate  in 

treatment,  669 
dental  tissues  in,  56 
spreading,  interior,  170 
in  dentin,  85 
Carnivora,  tooth  forms  in,  IS,  24,  34 
Casting,  gold  for,  380 

to  other  pieces,  381 
investments,  369,  374,  384 
Ritter  mixer,  378 
Taggart's  mixers,  375 
machines,  Custer's  electric,  382 
Jameson's  centrifugal,  383 
Price's  electric,  383 
Seymour's  stamping,  383 
Taggart's  pressure,   manner  of 
operating,  370 
nitrous  oxid  blowpipe  for,  371 
pressure  required,  3S1 
Taggart's  system,  367 
temperature  of  flask,  374 
Cataphoresis  for  bleaching  teeth,  539 
pulp  anesthesia,  403 


91. S 


i\i)i-:x 


C:i(  ajihorosis,  sonsitivo  dontin,  14S 
Ca\itics,  classififation,  l.W 
l)it  niid  fissure,  ]r)() 
.smoolli  surface,  lAG,  ITS 
exeavalinji;     under     analgesia,      14G 

(SVr  also  J)etitiii. 
filling  proximal,  with  gold,  258 
liningTS  for,  322 

inesio-approxinial    in   bicuspids  and 
molars,  selection  of  filling  niat(M-iai, 
329 
nomenclature,  1.54 

angles,  simple  cavities,  loo 
cavo-surface  angles,  15G 
division  into  thirds,  loo 
point  angles,  loo 
simple,  lo() 
walls,  1.55 
occlusal,  amalgam  and   gold   fillings 
for,  330 
cement  and  gold  fillings,  328 
fissure,  72       • 

zinc    phosphate    and    amalgam 
fillings  for,  326 
preparation,  for  amalgam,  277 
bicuspid  for  matrix,  242 
cement  steps  in,  241 
by  classes,  166 

first  step,   pit   and   fissure, 

166 
second     step,     removal    of 

softened  dentin,  174 
tliird  step,  shaping  for  re- 
sistance,   retention,    and 
convenience,  174 
dental    tissues    as    determining 

factor,  56 
dentin  instrumentation,  177 
dovetail  form,  176 
in  enamel,  71 

walls,  bevelling  antl  finish- 
ing, 177 
instrumentation,  178 
explanation  of  terms,  239 
extension  for  prevention,   indi- 
cations for,  244 
final  touches,  178 
Riling  material   as  determining 

factor,  177 
in  gingival  third,  178 
for  gutta-percha  fillings,  314 
in  incisors,  80 

for  inlays,  335.    t^rr  also  Inlays, 
instruments,  157 
burs,  163 
chisels,  1.57 
disks,    wheels,    and    ])oints, 

164 
excavators,  157 
sharpness  required,  147 
major  class  for  matrix  work,  239 
minor  class,  244 
in  molar,  for  matrix,  240 

in  buccal  surface  of  upper, 
75 
morti.se  form,  175 
in  proximal  surfaces  of  I)icusi)ids 
and  niolju's,  1S7 


C'avities,    prei)aration,  in  i)roximal   sur- 
faces of  inei.sors  and 
cus|)ids,  178 
incisal  angle  involved, 
185 
not  involved, 
178 
instrumentation,  183 
smooth  surface,  178 
steps  in,  157 
technique,  153 
])roximal,  amalgam  and  gold  fillings 
for,  329 
zinc    jjhosphate    and    amalgam 
fillings,  327 
l)roximo-occlusal,   cement    and   gold 
fillings  for,  328 
zinc    phosphate    and    amalgam 
fillings,  328 
wij)ing    with    carbolic    acid    before 
fining,  151 
Cements,  296 

action  of  oral  fluids  on,  302 

Ames'  copper,  for  deciduous  teeth, 

673 
arsenic  in,  301 

basic  zinc  phosphate,  use  of,  332 
contraction  and  exi)ansion,  302 
fillings,  alloy  and  cement,  331 

basic  zinc  phosphate  and  silicate 

combined,  331 
cavity  linings  for,  323 
combination,  325 
in  deciduous  teeth,  675 
finishing,  309 
with  gold,  328 
with  gutta-percha,  3.30 
matrices  for,  308 
packing  instruments  for,  30S 
protecting  with  i)araffin,  676 
{protection  from    moisture,  307 
for   inlay   manipulation,   357.       <S'(;c 
also  Inlays, 
.setting,  .301 
li(|ui(ls,  composition  and  u.s(>,  299 
maimer  of  keejnng,  .300 
turbidity,  301 
medicated,  for  l)ulp  capping,  .394 
mixing,  304 
oxyphos))liat<\  296 

of  coi)per,  indications  for,  304 
for  steps,  243 
])roi)erties  and  uses,  .302 
remov.al  of  old  root  canal  fillings,  431 
setting  and  strength,   modifications, 

300 
silicate,  201,  298 

fillings,  finishing,  309 
matrix  for,  308 
packing  instruments,  308 
properties,  304 
uses,  332 
S])alding  loop  for  carrying,  .327 
spatulas  for  mixing,  304 
steps  in  cavities,  241 
testa  for  volumetric  changes,  302 
zinc  oxychlurid,  296 

for  filling  root  canals,  457 


INDEX 


919 


Cements,  zinc-  pliospliatc,  201 

and  amalgam  tillinga,  32(3 
for  filling  dociduous  teeth, 

for    temjjorarv    operations, 
303 
Cement  oblasts,  101,  105 
Cementiim,  94 

formation,  95 

funetion,  61,  OS,  95 

histological  description,  94 

In-pert  rophy,  97 

structure,  97 
Chair,  cleanliness,  121 
Cheeks  in  dento-facial  operations,  SSO 
Children,  management  of,  667.     See  also 

Deciduous  teeth. 
Cliin  in  dento-facial  imperfections,  SSO 

retractor  in  orthodontia,  752 
Chisels  for  cavity  preparation,  157 

enamel  hatchets,  161 

formulae  for,  161 

gingival  margin  trimmers,  162 

uses,  173 
Chlorin,  instruments  for  appljang,  531 

manner  of  keeping,  531 

methods  for  bleacliing  teeth,  536 
Chloroform  for  general  anesthesia.     See 

Anesthesia . 
Chloropercha  for  root  canal  filling,  457 
Clamp-bands,  Angle's,  745 
Clamps  for  rubber  dam,  196 

Delos  Palmer's,  197 

Huey's,  196 

Southwick's,  196 

Woodward's,  217 
Cocain,  antidotes,  631 

in  local  anesthesia.     See  Anesthesia, 
local. 

IMeyer's    compound    high    pressure 
syringe,  401 

pressure  anesthesia  with,  401 

for  pulp  anesthesia.   See  Anesthesia, 
pulp. 

syncope,  treatment,  400 
Contact  points,  153 

in  gold  fillings,  218,  230 

in  lateral  incisors,  28 

in  upper  central  incisors,  25 
cuspids,  32 
Contouring    ai3paratus    for    dento-facial 

imperfections,  903 
Cotton,  removal  of  old  root  canal  filling, 
431 

rolls,  absorbent  and  non-absorbent, 
use  of,  199  • 
Crown-  and  bridge-work,  extirpation  of 

healthy  pulps  for,  391 
Crowns,  gold,  as  cause  of  pyorrhea,  473 

removing  gutta-percha  set,  317 

setting  with  gutta-percha,  313 

source  of  infection,  124 
Cuspids,  deciduous,  52 

fillings  in,  34 

odontography,  23,  30 

the  upper,  30 
Cusps,  evolution,  18 
Cysts,  peri-apical,  treatment,  452 


I)ec:iihious  teeth,  abscess  on,  453 
alveolar,  681 

chronic,   root  canal  fillings 
for,  462 
duration,  666 
effect  of  cand}-,  682 
extraction,  586 
filling,  amalgam,  676 

application  of  rubber  dam, 

673 
cement,  675 

Ames'  copper,  673 
cavity  preparation,  675 
protecting   filling  with 

paraffin,  676 
zinc  phosphate,  673 
Gilbert's    temporarj^   stop- 
ping, 676 
gutta-percha,  312,  670 

advantages  and  disad- 
vantages, 673 
Hollingsworth     space 

guard,  672 
occlusal  cavities,  670 
proximal  cavities,  672 
incisor  cavities,  676 
materials,  331 
pulp  protection,  675 
tin,  678 

and  gold,  678 
gum  lancing  to  facilitate  erup- 
tion, 664 
indications,  665 
technique  of  operation, 
665 
management,  664 
odontography,  51 
premature  loss  as  cau,se  of  mal- 
occlusion, 721 
prolonged  retention  a  cause  of 

malocclusion,  724 
prophylactic  treatment,  682 
pulp  canal  filling,  6S0 

aqua  ammonia)  in,  680 
devitalization  and  ex- 
tirpation, 678 
devitalizing  paste,  679 
mummifying  paste,  680 
occlusal  cavities,  679 
proximal  cavities,  697 
salol  in,  681 
reasons  for  preservation,  666 
root  canal  fiUings,  462 
treatment  of  caries  with  silver 
nitrate,  669 
of  odontalgia,  668 
Deformities.    See  Dento-facial  Imperfec- 
tions; also  IMalocclusion. 
Dehydration  of  dentin,  146 
Dentin,  anesthesia  by  pressure,  642 
chemical  anah'sis,  8^ 
dehydration,  146 
desiccation,  146 
exposed,  silver  nitrate  for,  151 
formation  of  secondarj-,  145 
granular  layer  of  Tomes,  87 


920 


INDEX 


Dentin,  hislolofiicul  dc.scrij)tion,  .S3 
interf>:l()l)ul;ir  spaces,  88 
in  root ,  85 
secondary,  89 
sensitive,  145 

anesthesia,  401 
medication,  topical,  148 
carbolic  acid,  151 
cataphorosis,  148 
cauterants,  151 
cocain  analgesia  with  press- 
ure syringe,  148 
hydrochlorid,  148 
ether  or  ethyl  chlorid,  148 
hot  water,  148 
injecting  cocain  into  gum 

tissues,  149 
Robinson's  remedy,  151 
silver  nitrate,  151 
vapocain,  148 
zinc  chlorid,  151 
pulp  extirpation  in,  391 
treatment,  46 

under    general    anesthesia, 

150  ^    ^ 

under   partial    ether    anes- 
thesia, 150 
by  temporary  filling,  151 
.  sheaths  of  Neumann,  84 
structure,  82 
Dentinal  tubules,  83 

direction,  84 
Dentition,     pathological     complications, 

664 
Dento-enamel  junction,  87 
Dento-facial  imperfections,  873 
causes,  873 
local,  873_ 
I)hysiological,  874 

eruption  of  teeth,  874 
irregularities  of  teeth,  876 
naso-maxillary     sinus    dis- 
ease, 876 
diagnosis,  878 
protrusions,  upper,  881 
treatment,  881 

by  extraction,  SSI 
by  "jumping  the  bite,"  882 
retruded  and  contracted  dental  and 
maxillary  arch,  889 
treatment,  889 

contouring  apparatus,   903 
upper  incisors   and   intermaxil- 
lary process,  888 
retrusions,  upper  dental  and  maxil- 
lary, 887  _ 
Dentures,  artificial,  extraction  of  sound 

teeth  preparatory  to  inserting,  546 
Deposits  on  teeth,  removal  of,  135 
Desiccation  on  dentin,  146 
Development  of  tooth  forms,  18 
Diphtheria,  auto-infection,  125 
Discoloration  of  teeth,  428,  519 
chemical  processes,  520 
from  death  of  exposed  pulp,  523 
from  metallic  salts,  542 
from  i)ul})  removal,  405 
treatment,  524    Sue  also  Bleaching. 


Discolored  teeth,  cement  lining  for  fill- 
ings in,  329 

Disinfectant,  definition,  128 

Disks  for  cavity  prej)aration,  164 

Division  of  food,  17 

Dolichocej)halic  j)eoi)les,  type  of  dental 
arch  in,  20 


Electric  mallet,  213 
Elevators  for  extracting  roots,  558 
Empyema  of  antrum,  439,  451 
Enamel,  brown  bands  of  Retzius,  69 
chemical  composition,  61 
incremental  lines,  70 
manner  of  cutting,  62,  66 
origin,  59 
rods,  direction,  68 
sections,  action  of  acids  on,  61 
stratification  bands,  69 
striations,  63 
structure,  61,  63 

walls,   histological  requirements  for 
strength,  71 
Engine  mallet,  214 
Entoconid,  19 
Eruption  of  teeth,  changes  of  peridental 

membrane,  117 
Escharotics,  carbolic  acid,  127 

zinc  chlorid,  127 
Ether  for  general  anesthesia.    See  Anes- 
thesia, 
for  partial  anesthesia,  150 

apparatus    for    administration, 
1.50 
spray,  for  obtunding  sensitive  den- 
tin, 148 
Ethyl  chlorid  for  local  anesthesia.     See 
Anesthesia, 
spray  for  obtunding  sensitive  den- 
tin, 148 
Eucalypto-percha  for  root  canal  filling, 

4.57 
Euca-percha  for  root  canal  filling,  457 
Evolution  of  tooth  forms,  18 
p]xamination   of   teeth   and   oral    cavity 
preliminary  to  operation,  135 
technique,  138 
Excavating  cavities.     See  Dentin. 
Excavators  for  cavity  preparation,  157 
contra-angled,  160 
formula;  for,  159 
hatchets,  159 
hoes,  169 
spoon-shaped,  160 
sterilization,  120 
Expansion  arches.  Angle's,  743 
Exploring  instruments,  136 
Extraction  of  teeth,  545 
accidents,  606 
.'ifter  subperiosteal  injection  of  loc^al 

anesthetic,  637 
after-treatment,  605 

under  anesthesia.    See  Anesthe- 
sia, 
anti.sepsis  imjjortant,  126 


INDEX 


021 


Extraction,  antiseptic  precautions,  l'-- 
deciduous,  oSt) 
•rencral  jirinciples  for,  579 
hemorrhage,  control,  607 
impacted  lower  tliird  molars,  602 

comiilications,  601 
indications  for,  o-lo 
infection  through,  125 
injudicious,    cfTeet    on    facial    lines 

719 
instruments  and  accessories,  o-lb. 
elevators,  558 

manner  of  using,  582 
forceps,  5-lS 
joints,  549 
for  lower  teeth,  553 
manner  of  using,  583 
selection  of,  550 
for  upper  teeth,  550 
lancets,  559 

mechanical   mouth-opener,    560 
mouth  props,  559 
osteotome,  Cryer's,  603 
pharyngeal  forceps^,  560 
root  extractors,  558 
scissors,  559 
selection  and  use,  581 
lancing,  583 

malformed   and   abnormally   placed 
teeth,  595,  602 
diagnosis  by  radiograph,^  596 
malocclusion  produced  by,  70S 
molar,  first,  serious  consequences  of, 
'     830  ^  ,,      . 

mutilation,      treatment      following, 

828 
necrosis,  alveolar,  following,  453 
permanent    lower,    anterior    teeth, 
591 
bicuspids,  592 
molars,  first,  593 

effects  of,  21 
second,  594 
third,  594 
permanent  upper,  bicuspids,  588 
canines,  588 
central  incisors,  587 
lateral  incisors,  588 
molars,  first  and  second,  589 
third,  590 
physiognomy,  relation  to  the  saving 

and, 893 
position  of  operator,  581 

of  patient,  580 
in  protrusion,  upper,  886 
of  roots  with  elevators,  581 
sound  teeth  preparatory  to  artificial 

dentures,  546 
sm-gical  anatomy,  561 

abnormalities     in     position     of 

teeth,  578 
alveolar  process,  561 
bicuspids,  second,  567 
impacted  third  molars,  573 
in  negroes,  566 
relation    of    teeth    to    internal 

structm-e  of  jaws,  565 
root  forms,  565,  568 


Fack,  fistulic  on,  treatment,  451 

restoration  to  symmetry  by  ortho- 
dontic treatment,  717 
Facial  art,  709 

scar,  depression  of,  treatment,  451 
Fibroblasts,  104 

Files  for  finishing  gold  fillings,  231 
Fillings  in  bicuspids,  lower,  50 
upper,  49 
for  cavities  in  enamel,  71 
combination,  324 
in  cuspids,  34 

in  deciduous  teeth,   amalgam,  676. 
See  also  Deciduous  teeth, 
gold,  678 

and  tin,  678 
tin,  678 
of  glass.     See  Inlays, 
of  gold,  finishing,  228.    See  also  Gold, 
instruments  for,  230 
repairing,  232 

starting,  217,  219,  221,  223,  225 
in  incisors,  24 
manner  of  inserting  material  with 

matrix,  242 
materials,  advantages  and  disadvan- 
tages, 324 
for  anterior  teeth,  selection  of, 

329 
selection  of,  201 
of  metal,  causing  pulp  irritation,  392 
in  molars,  lower,  50 

upper,  50 
porcelain  rod.    See  Inlays, 
root  canals.    See  Root  canals, 
separation  preparatory  to,  140 
temporarv,  gutta-percha,  312 
of  tin,  226 
Fissures,    occlusal,    cutting    out    m 

cuspids  and  molars,  72 
Fistulse,  in  antrum  of  Highmore,  treat- 
ment, 451 
on  the  face,  treatment,  451 
in  pyorrhea  alveolaris,  500 
treatment,  448 
Food,  division,  17 
insalivation,  17 
mastication,  17 
prehension,  17 

soft,   cause  of  dental  irregularities, 
725 
Forceps  for  extracting,  548 
infection  through,  126 
sterihzation,  122 
Formaldehyd,    investigations   on   germi- 
cidal power,  129 
for  putrescent  pulp  treatment,  429 
lamps,  129 
Formalin  as  sterilizing  agent,  134 
Formocresol   for  putrescent   pulp  treat- 
ment, 422,  430  , 
Formopercha  for  root  canal  filling,  40/ 
Fossa,  definition,  173 
Frenum   labiorum,^  abnormal,    cause   ot 

malocclusion,  725 
Fumigation,  130 


bi- 


922 


INDEX 


Function  of  tooth,  17 
Furnaces,  coke,  old  stylo,  362 
electric,  Caster's,  362 
Hannnond's,  362 
Pclton's,  364 
Wliite's,  363 
pas,  Land's,  362 
gasoline,  lirophy's,  364 
Turner's,  364 


G 


Gangrene.    Sec  Pulp  gangrene. 
Germicide,  definition,  128 
Gingivitis.    See  Pyorrhea  alvoolaris. 
Glass  inlays,  334 
Cilasses,  sterilization,  121 
Gold,  ada])tingto  cavity  walls,  techniciue, 
209 
and  amalgam  fillings,  329 
ver.sus  amalgam  fillings,  32.5 
annealing,  208 
automatic  pluggers,  211 
for  casting,  380 
casting   to   other   pieces,   481.      See 

also  Inlays,  cast  gold, 
and  cement  fillings,  328 
cohesive,  indications  for,  238 

objections  to,  237 
condensers,  210 
crystal,  207 
electric  mallet,  213 
engine  mallet,  214 
for  filling,  201 

fillings,  cement  lining  for,  329 
by  classes,  217 

proximal  surface  cavities  of 
bicuspids  and  molars,  22 1 
proximal  surface  cavities  of 
incisors  and  cuspids  in- 
volving incisal  angle,  220 
])roximal  surface  cavities  of 
incisors  and  cuspids  not 
involving    incisal    angle, 
218        _ 
small    cavities    in    occlusal 
surfaces  of  bicuspids  and 
molars,  224 
smooth  surface  cavities  in 
gingival   third  of   labial, 
buccal,  and  lingual   sur- 
faces, 217 
cohesive  and  non-cohesi^•e,  fill- 
ing   proximal    cavities    with 
anterior  teeth  matrix,  258 
contact  jjoints,  218,  230 
finishing,  228 

with  burs,  228 
instruments  for,  229 
files,  231 
knives,  231 
with  i)f)ints,  corimdum,  228 
liindostan,  229 
wood,  228 
matrices  for.     Sec  Matrices, 
with  matrix,  finishing,  249 

manner  of  int  roduct  ion,  242 


(Jold  fillings  with  matrix,   pluggers  for, 
2.-)9 
in  proximal  surfaces  of  bi- 
(!usi)ids  and  molars,  224 
repairing,  232 

with  amalgam,  233 
in  fracture  of  walls,  233 
with  gutta-percha,  233 
starting,  217,  219,  221,  223,  225 
foil,  cohesive,  205 

action  of  gases  on,  205 
advantages,  205 
formation  of  cushions  from, 
248 
soft  or  non-cohesive,  202 
cylinders,  204 
mats,  203 
rolls,  204 
tape,  203 
inlays.     See  Inlays, 
introduction  of,  209 
moss  fiber,  207 
and  platinum,  208 
plugger  points,  216 
plugging  instruments,  210 
preparation  for  matrix  fillings,  246 
puritv  rec(uired,  202 
arid  fin  fillings,  2.39,  249,  321 
trimmers,  Rhein's,  249 
Gum  lancing,  antiseptic  precautions,  121 
to  facilitate  eruption  of  decidu- 
ous teeth,  664 
Gutta-percha,  309 

and  cement  fillings,  330 
chemical  changes  in,  311 
classes,  311 

combined  with  other  materials,  318 
decay  in  the  mouth,  313 
fillings,  cavity  preparation,  314 
in  deciduous  teeth,  670 

Ilollingsworth's  space- 
guard  in,  672 
finishing,  316 
instruments,  317 
trimmers,  316 
and  gum  shellac,  318 
heaters,  314 
Hill's  stopping,  310 
hot-air  syringe  for  softening,  317 
indications  for  employment,  312 
manipulation,  314 
with  medicinal  agents,  318 
physical  properties,  311 
for  repairing  filings,  233 
for  root  canal  filling,  456 

removal  of  old,  431 
and  rubber,  properties,  310 
temj)orary  stopjHng,  318 


H 


Habits,  pernicious,  cause  of  malocclu- 
sion, 724 

Hand-pieces,  sterilization,  121 

Hands,  i^reparation  previous  to  opera- 
ting, 133 

Headgear  in  orthodontia,  7.50 


JXDh'X 


02.3 


IhMiinphiliacs,  syslcinic  l  rcaiiuciit,  ()()i) 
Ileinorrliago,  control  aflcr  cxf  rad  ion,  ()()7 

local,  007 

after  ])ulp  rcinoval,  KM) 

.systemic,  609 
Hcrbivoni,  tooth  forms  in,  24,  'A-i 
Histology,  dental,  CM 
Howsliip's  lacmitr,  96,  110 
Hydrogen  dioxid  for  bleaching  teeth,  r)34 
danger  of  use  in  absc(\ss  treat- 
ment, 442,  44S 
Hydronaphthol     for     sterilizing     instru- 
ments, 132 
Hygiene,  oral,  123,  910 

necessity  in  jMibhc  schools,  12.5 
Hypocone,  18 
Hypoconulid,  19 


Impaction  of  teeth,  .573,  .59.5 
canines,  .588,  597 
disturbances  due  to,  600 
extracting  operation,  choice  of,  602 
frequency,  order  of,  595 
third  molar,  573,  595 
Implantation  of  teeth,  precautions,  127, 
655.     See  also  Plantation, 
technique  of  operation,  658 
incision,  659 
instruments,  660 
preparing  sockets,  660 
terminology,  646 
Impression     material     for     orthodontia 
models,  733 
trays,  734 
Incisors,  cervix,  24 

choice  of  fillings,  24 
cingulum,  24 
deciduous,  51 
lateral,  26 
lower,  29 
odontography,  23 
tubercles,  25 
upper  central,  24 
retruded,  888 
Incremental  lines  in  enamel,  70 
Infection,  caution  against,  122 
external,  126 
through  the  mouth,  118 
from  mouth  to  mouth,  125 
from  oral  bacteria,  123 
oral,  bridge-work  a  source  of,  124 
crowns  a  source  of,  124 
through  extraction,  125 
vaccine  therapy  in,  509 
of  pulp,  clangers,  123 
Inflammation    from    bacterial    invasion 
around  lower  third  molars,  124 
gingival,  due  to  faulty  crowns,  124 

due  to  neglect  of  antisepsis,  123 
peridental,    due    to    faulty    crowns, 

124 
from  rubber  dam,  120 
Infra-occlusion,  treatment,  825 
Inlays,  advantages,  335 
amalgam,  327,  331 


ays,    cavity    ])reparalioii    for    j)il    .•iiid 
fissuH!  cavities,  l(>(i 
cement,  for,  301 
cemented,   restoration   of   teeth  bj', 

333 
glass,  334  ^ 

Land's  matrices  for,  334 
gold,  364 

Alexander's  method  of  making, 

384 
cast,  367.     See  also  Casting, 
cavity  preparation,  335 

in        bicuspids        and 
molars,  345 
finishing,  371 
impression  and  die  method  for, 

388 
investments  for,  374,  384 
mixing,  375 

Ritter  mixer,  378 
Taggart's  mixers,   375 
selection  of  gold,  380 
setting,  371 

wax  model  for,   345.     See  also 
Wax. 
burning  out  the  wax, 
379 
Taggart's  au- 
tomatic ap- 
paratus,379 
carving   with   Roach's 

suction  carver,  346 
investing,  369,  376 
making,  367 
mounting      on      sprue 
wire,  369 
matrix,  364 

incisal     tips     on     anterior 

teeth,  366 
indications  for,  365 
method  of  building  up  with 
blowpipe,  366 
of  making  matrix,  366 
Rowan's  decimal  gold  for, 
366 
versus  porcelain,  336 
impression  and  die  method,  advan- 
tages, 387 
models     of     amalgam,     method     of 

making,  387 
in  molars,  upper,  50 
porcelain,  baking,  350 

cavity  preparation,  335 

abrasion    or    erosion    cavi- 
ties, 337 
in  bicuspids,  343 
gingival,    extending    under 

gum  margin,  341 
incisal,  340,  342 
labial,  338 
in  molais,  343 
proximal,  339,  342 
simple,  336 
cements   and   manii)ulation   for 

setting,  357 
furnaces,  362 
fusing,  359 

electric  current  in,  360 


924 


INDEX 


Inlays,  porcelain,  fusing,  ])vr()in('k'r  for,  [ 
359 
ground  rod,  333 
hydrofluoric  acid  for  rouglu'iiing 

cavity  surface,  352 
impression  and  die  method  for, 

387 
low  fusing,  353 
baking,  356 

l)uilding  up   the  porcelain, 
356 
corners,  357 
gold  matrix  for,  353 

making  with  wax 
form,  355 
instruments,    for    manipu- 
lating    porcelain 
paste,   353 
for  shaping  matrix,  353 
matrices  for,  335 

filling  matrix,  349 
forming,  347 

with   burnishers,    ball- 
pointed,  348 
Reeves',  350 
Sausser's,  351 
platinum  foil  for,  348 
removing  from  finished  in- 
lay, 352 
trimming  after  first  fusing, 
351 
mixing  the  porcelain,  349 
rod.  How's  burs  for,  333 

Weagant's  instruments,  333 
selecting  shades,  351 
setting,  352,  357 
shading,  357 
shrinking,  350 
staple  anchorage  for,  342 
swaging  process  in  making,  386 
varieties  of  material  for,  360 
Brewster  press,  388 
materials,  389 
Insalivation  of  food,  17 
Insectivora,  tooth  forms  in,  18 
Instruments    for    bleaching     teeth    with 
chlorin,  531 
extracting,  548 
implanting  teeth,  661 
orthodontia.    See  Orthodontia  tools, 
plugging  gold,  210 
scaling  teeth,  486 

sterilization,  by  boiUng  in  water  and 
soda,  131 
formaldehyd,  130 
Interdental  spaces,  creating,  preparatory 

to  filling,  140 
Interglobular  spaces,  88 
Intermaxillary  process,  retruded,  888 
lodin  for  bleaching  teeth,  534 

in  treating  pyorrhea  alveolaris,  489 
lodoformagen  for  pulp  cai5i)ing,  394 
lodoglycerol  in  treating  pyorrhea  alveo- 
laris, 492 
Irregularities,  881.    See  Dento-facial  im- 
perfections, 
of    teeth.      ;SVe    Malocclusion;    also 
Orthodontia. 


Knives  for  lini.shing  gold  fillings,  231 


Lactic  acid  in  scaling  teeth,  491 

Lancets,  559 

sterilization,  121 

Lancing  gums,  121 

Lead  for  fillings,  201 

Lips  in  dento-facial  imperfections   880 
pressure  in  occlusion,  696 
retrusion  of  entire  upper  lip,  888 
sucking,    a    cause    of    malocclusion. 
724 

Lobes  in  incisors,  three,  24 


M 


Magnifying  glass,  137 
Malformation  and  malposition  of  teeth, 
diagnosis  before  extracting,  595 
disturbances  due  to,  600 
Mallets,  automatic.  Abbott's,  213 
Foote's,  211 
Salmon's,  213 
Snow  and  Lewis',  211 
electric,  Bonwill's,  213 
mechanical  engine,  Bonwill's,  214 
Buckingham's,  216 
Homes',  216 
Malnutrition,    relationship    to    pyorrhea 

alveolaris,  502 
Malocclusion,  absence  of  teeth,  partial, 
718 
Angle's  classification,  701 
brief  sunmiary,  708 
nomenclature,  701 
definition,  683 
etiology,  721 

abnormal  frenum  labiorum,  725 
disuse  of  teeth,  725 
enlarged  faucial  tonsils,  721 
loss  of  permanent  teeth,  724 
pernicious  habits,  725 
})remature     loss     of     deciduous 

teeth,  721 
prolonged  retention  of  deciduous 

teeth,  724 
supernumerary  teeth,  724 
tardy    eruption    of    permanent 
teeth,  724 
from  extraction,  70S,  719 
forces  governing,  697 
arches,  697 
lips,  697 

malposition  of  teeth,  698 
mouth-breathing,  699 
stress,  700 
tongue,  699 
face,  effects  on  beauty  of,  709 
facial  asymmetry,  as  cause  of,  714 
examples  of  the  various  classes, 
715 
infra-occlusion,  treatment,  825 


INDEX 


925 


Malocclusion,  pro[)ortion  of  occurrences 
of  types,  709 
Ireatnient.     ^Vc  Ortliodonjia. 
Malposition    of    teeth,    pruducinj^    mal- 
occlusion, 698 
Mammals,  teeth  in,  17,  23,  34 
Margins,  formation  in  enamel,  75 
Mastication,  dynamics  of,  21 
of  food,  17 
occlusion  in,  21 
Matrices,  for  anterior  teeth,  256 

filling  proximal  cavities  with 
gold,  258 
auxiliary,  261 

contour,   for  molars  and  bicusi)ids, 
Crenshaw's,  255 
Hodson's,  254 
forms,  for  molars  and  bicuspids,  250 
Brophy's,  250 
Crenshaw's,  253 
Guilford's,  251 
Hewett's,  252 
Jack's,  259 
Lodge's,  252 
Woodward's,  251 
general  considerations,  235 
in  gold  fillings  in  proximal  cavities 
of  anterior  teeth,  258 
surfaces    in    bicuspids 
and   molars,   224 
indications  for,  238 
selection  of,  236 
Matrix  work,  cavity  preparation  of  the 
major  class  for,  239 
of  the  minor  class  for, 
244 
manner  of  inserting  filling,  242 
pluggers  for,  259 
Maxillary  bones,  influence  of  teeth  on 
development  of,  873 
retrusion,  887 
Membrana  eboris,  90 
Mercury,  as  solvent  for  metals,  263.    See 

also  Amalgams. 
Models  in  orthodontia,  733 

plane  for,  737 
Moisture,  exclusion  of,  191 
Molars,  deciduous,  52 

reasons  for  preserving,  666 
first  permanent,  as  key  to  occlusion 
689  _ 
extraction,    serious     conse- 
quences, 830 
fourth,  49 

impacted    third,    surgical    anatomj^, 
573 
extraction,  590,  595,  602 
lower  first,  44 
second,  46 
third,  48 

inflammation   around,    due 
to  bacterial  invasion,  124 
odontograph}^,  23,  39 
phylogenesis,  18 
triangles  of,  18 
upper,  40 
first,  41 
second,  43 


Molars,  upper,  third,  47 
Mori)hin,  idiosyncrasies  to,  441 
Mouth  mirrors,  137 
electric,  139 

l)rops,  559 
Mouth-breathing  in  malocclusion,  699 
Mucous  membrane,  infection,  124 
Mummification  of  pulp,  462 

in  deciduous  teeth,  680 
Myeloplaques  in  peridental  membrane, 
110 


N 


Napkins,  aseptic,  199 
sterilization,  121 
use  with  rubber  dam,  198 
Nasmyth's  membrane,  115 
Nausea  from  rubber  dam,  200 
Necrosis  and  caries  of  bone,  due  to  ab- 
scess or  extraction,  453 
following  extraction,  125 
Negroes,    anatomical    considerations    in 

extracting  teeth  of,  566 
Neumann,  slieaths  of,  84 
Nickel  silver  for  regulating  appliances, 

741 
Nitrous  oxid  for  general  anesthesia.    See 

Anesthesia. 
Nose  in  dento-facial  imperfections,  880 
Novocain  in  local  anesthesia.    See  Anes- 
thesia. 


Occlusion  of  the  teeth,  20 
Bonwill's  "law,"  693 
definition,  683 

effect  on  facial  symmetry,  714 
forces  governing  normal,  695 
arches,  695 
lips,  696 
importance  of  first  permanent  molar, 
689 
in  filling  technique,  154 
key  to,  689 
line  of,  692 
normal,  684 

relationship  of  individual  teeth,  684 
Odontalgia,     See  Toothache. 
Odontoblastic  cells,  89 

processes,  90 
Odontography,  17 

Operative  appliances  and  methods,  135 
Opsonic  index,  method  of  determining, 

514 
Opsonins  and  opsonic  index,  512 
Oral  prophjdaxis,  910 
Orthodontia,  683.    See  also  Dento-facial 
orthopedia.   Malocclusion,   Occlu- 
sion, 
adjustment  and  operation  of  appli- 
ances.   See  Regulating  appliances, 
anchorage,  764 
Baker's,  768 
details,  765 


yi'i. 


ISDEX 


Orllioil'iiil  i.i,   aiicliorajic,    inh  rMi;i\ill;ir\-, 
7(17 
comhiiiiitions  i'oi,  7S() 
occipital,  767 
))riiicil)l('s,  liW 
rccii)n)("il,  7(30 
.sinijilc,  7(i6 
tstatioiKiry,  7()<) 
Aiifj;lo's    cla.ssificaticjii    of    malocclu- 
sion, 701 
brief  summary,  708 
bands,  757 

attachinji    spurs,    sta])l(s,     and 

lubes,  7()1 
for  canines,  703 
fitliiifi:,  760 
solderiiifi,  760 
definition,  6S3 

extraction  contraindicated,  71!) 
forces  applied  in  reKulatinfi,  76o 
impressions,  material  for,  733 
mcthoci  of  taking,  731 
lower,  736 
upper,  73o 
trays,  734 
varnishing,  736 
models,  733 

plane  for,  737 

jiouring  and  sejiarating,  737 
])hotographs  for  records,  73S 
jirinciple  of  facial  symmetry,  71(J 
regulating  appliances.     See  Regula- 
ting appliances, 
retention.    See  Retention. 
Rontgenographs  for  diagnosis,  738 
soldering,  757 

soft-soldering  sheath-hooks  and 

spurs,  763 
tube  to  band,  759 
tissue  changes  during  retention,  799 
tools,  753 

band  driver,  755 
blowpipe,  755 
Griuiberg's  holder,  757 
hand  mallet,  755 
Oppenheim's  holder,  755 
pliers,  753 

bandforniing,  754 
How's,  755 
regulating,  7.53 
soldering,  753 
scissors,  755 
wire-cutters,  755 
wrenches,  755 
tooth   movement,    alveolar   jjrooe.ss, 
and  peridental  membrane  in, 
726 
physiological      changes     subse- 
quent to, 730 
in  alveolar  process,  730 
in  the  teeth,  730 
])ulp  in,  729 

tissue  changes  incident  to,  726 
in  depressing  a  tooth, 

727 
in  elevating  a  tooth, 

727 
in  moving  teeth,  728 


( )r(li(»d(iiil  i.i,    lo'illi,    I  i^sue     clian^ics    in 
lotating  Icctli,  72S 
Irealment,  80S 

cases  of  Class  1,  810 

arch  widening  and  nar- 
rowing, 812 
infra-occlusion,  825 
mutilation    by   extrac- 
tion, 828 
ca.ses  of  Class  II,  Division  1 ,  831 
anchorage,    intermaxil- 
lary, 85! 
molar  and  occipi- 
tal, 851 
ap|)lian(!es  for  retract- 
ing incisors  ami  ca- 
nines, 851 
arrested  growth  of  man- 
dible, 845 
extract  i<jn  of  first  ujiix-r 
premolars    contrain- 
dicated,  850 
Kingsley's  method,  8.50 
"jumping      the 
bite,"  8.53 
minimizing  pain,  846 
regulating,  technirpie, 

838 
retention,  843 
cases   of   Class   II,   Division    J, 

subdivision,   856 
cases  of  Class  II,  Division  2,  857 

vulcanite  plates,  861 
cases  of  Class   II,    Division  2, 

subdivision,  862 
cases  of  Class  III,  864 
appliances,  867 
early  treatment  impor- 
tant, 864 
faucial  tonsils,  866 
resection   of   the   jaw, 
doublcj  871 
cases  of  Class   III,  subdivision, 

871 
importance   of   early    hiterven- 

tion,  733 
l)reliminary  considerations,  808 
and  rhinology,  cociperation  of,  701 
Orthodontist,  art  study  for,  709 
Orthopedia,  contouring  apparatus,  903 
anchorage,  905 
apparatus    for    retruding    roots 

of  teeth,  908 
bending  pliers,  909 
j)ower  bows,  905 
treatment  adjustments,  907 
(lento-facial,  873 
principles,  879 

relations  of  jihysiognomy  to  saving 

and  extraction  of  teeth,  893 

Osmosis,  electric,  for  sensitive  dentin,  148 

Osteoblasts  in  peridental  membrane,  108 

Osteoclasts  in  perident;d  menibnine    110 


Pacifier,  a  cause  of  malocclusion,  724 
Pain,  referrctl  in  jjulps,  93 


INDEX 


027 


Paraoone,  18 

Paraffin  for  roo(.  canal  lillinji;,  45S 
Perforation.     *S'«'  Hoof,  canal. 
Porhydrol  for  l)leacliins  teeth,  535 
Pericemental  tissue,  hypertrophy,  treat 

inent,  455 
Pcriecnientitis,   apical,  treatment,  431 
from  neglect  of  antisepsis,  123 
non-septic,  treatment,  454 
rubber  dam  guard  in,  440 
suppurative,  causes,  432 
Pericementum,  59,  97 
Peridental  membrane,  59,  97 
Black's  "glands,"  495 
bloodvessels,  117 
cellular  elements,  104 
cementoblasts,  105 
changes  v^'ith  age,  117 
epithelial  structure.  111 
fibers,  100 
functions,  98,  104 
nerves,  117 
in  orthodontia,  726 
osteoblasts  in,  108 
osteoclasts  in,  110 
so-called  "glands"  of,  113 
structural  elements,  98 
Periosteum,  dental,  97 
Phenolsulphonic  acid  for  abscessed  teeth, 

448 
Phylogenesis  of  molars  in  man,  19 
Physiognomy,    influence   of    teeth,    873. 
See  also  Orthopedia,   facial,   and 
Dento-facial  imperfections, 
relations  to  saving  and  extraction  of 
teeth,  893 
Pins,  removal  from  root  canals,  432 
Plantation  of  teeth,  646 
anesthesia,  658 
artificial  crovi^ns,  656 

roots,  654 
asepsis,  656 

biological  conditions,  647 
care  of  planted  teeth,  653 
retention  cap,  6.53 
stimulation  of  gum,  654 
history,  646 

mode  of  attachment,  654 
precautions,  655 
preparation  of  teeth  for,  651 
pericementum,  652 
root  filling,  652 
scion  tooth,  651 
resorption  of  roots,  663 
technique  of  operation,  658 
instruments,  660 
Plastics,  262 
Plates.    See  Dentures. 
Platinum,  behavior  in  casting,  380 

and  gold  in  fillings,  208 
Pluggers  for  amalgam,  282 
Bing's,  210 
for  matrix  work,  259 
points,  216 

Chappell's,  217 
Varney's,  217 
Webb's,  217 
Points,  for  cavity  preparation,  164 


Points,   corundimi  for  liuisliiiig  gol'l  fill- 
ings, 22S 
Ilindostan,  229 
wood,   228 
L'olishing  points,  wood,  for  gold  fillings, 

22S 
Porcelain  cavity  stoppers,  334 

comparative  fusing  points,  362 
furnaces,  362 

high  fusing  versus  low  fusing,  361 
for  inlays,  varieties  of,  360 
inlay  for  labial  surface,  218 
low  fusing.    See  Inlays, 
rod  inlays,  333 
Prehension  of  food,  17 
Premolars,  odontography,  23,  35 
Prophylactic     treatment     of     decidu(jus 

teeth,  682 
Prophylaxis,  oral,  123,  910 
Protocone,  18 
Protrusions,  upper,  881 
Pubhc  schools,  necessity  of  oral  hygiene 

in,   125 
Pulp,  89 

abscess,  395 

anesthesia,  aids  in  difficult  cases,  403 
by  adrenahn  and  formaldehyd 

pressure,  400 
by    carbolic    acid    and    cocain 

pressure,  403 
by    cocain-adrenalin    injection, 

404 
by  cocain  cataphoresis,  403 
by  cocain  pressure,  399 
by  high  pressure  syringe,  den- 
tinal, 402 
methods,  399,  643 
by  nervocidine,  403. 

Soderberg's  improved 

method,  403 
pressure,  642 
bloodvessels,  93 
canals,  in  bicuspids,  lower,  39 
upper,  36 
in  canines,  lower,  33 

upper,  32 
in  incisors,  lower  central,  30 
upper  central,  26 
lateral,  28 
in  molars,  deciduous,  53 
lower  first,  46 
second,  47 
third,  49 
upper  first,  43 
second,  43 
third,  48 
caijping,  394 

contraindications,  393 
medicated  cements  for,  394 
chamber,  opening  into,  411 
dangers  from  infection,  123 
death  of,  causing  discoloration,  519 

spontaneous,  425 
devitalization,  accidents  from  arsen- 
ical applications,  408 
allaying  pain  from  arsenic  dress- 
ing, 407 
arsenic,  404 


928 


INDEX 


Pulp   (l('vit;iliz;itioii   in   (Icc'nluous    icclh, 
4()<),  ()7S 
ill  fraclurcd  teeth.   lOS 
objections  to  arsenic.  40") 
sealinj!;  tlie  arsenic,  4()() 
devitalizinfi;  fiber,  40G 

paste,  400 
digestion,  Harlan's  paste  for,  4(i3 
exposure,  cement  for,  314 
extirpation,  410 

under  anesthesia,  general,  399 
anesthetizing   ajHcal   remnants, 

408 
antiseptic  i)recautions,  415 
l)roaches  for,  412 
of  healthy,   covered  with  suffi- 
cient dentin,  391 
hemorrhage,  treatment,  400 
removal  of  debris,  415 
root-canal  dressing  after,  401 
special  methods  of  preparing  for, 

408 
of  vital,  covered  with  sensitive 
dentin,   391 
functions,  93 
sensorv,  93 
vital,  93 
gangrene,  395 
dry,  425 
moist,  426 

without  pericementitis,  426. 
See  also  Pulp,  putrefac- 
tion, 
treatment,  429 
histological  description,  89 
hyperemia,  causes,  392 
hyperplasia,  treatment,  398 
infection,  by  way  of  apical  tissue,  397 
by  way  of  blood  stream,  398 

of  dentin,  394 
in  pyorrhea,  398 
pathology,  395 
irritation,  from  arsenic  in  cements, 
301 
from  large  metal  fillings,  392 
mummification,  425,  462 
of  root  portion,  461 
nerves,  93 

nodules,  treatment,  403 
pain,   referred  in,   93 
protection,  gutta-percha  for,  312 
putrefaction,  426 

etiology  and  pathology,  426 
symptomatology,  428 
treatment,  429 
putrescent,  reaction  to  hot  and  cold, 

395 
spontaneous  death  of,  425 
in  tooth  movement,  729 
treatment,  when  dead,  42 

dry    gangrene,    425.      See 
also  Root  canal  treatment . 
mummifying  pastes,  425 
ulceration,  396 

vital,  exposed,  indications  for  preser- 
vation, 393 
Jack's  reactions  to  cold  and  hot, 
395 


Pulj),    vital,    treatment    of    recently    ex- 
posed, 392 
.septic,  treatment,  395 
Puli)itis,  chronic,  pathology,  428 
Pj'orrhea    alveolaris,    ab.sce.s.ses    ami    fis- 
tuUe  in,  501 
antiseptic  drugs  for,  503 
bismuth  paste,  503 
silver  iodid,  503 
of  arthritic  type,  502 
bacterial  infection  in,  495 
constitutional  predisposition,  494 

jiredisposing  factors,  .504 
definition,  4(54 
destruction  of  alveclar  bony  tissue, 

498 
diagnosis,  differential,  500 
from  scorbutus,  500 
from  specific;  infections,  500 
from  \'incent's  angina,  500 
epithelial     remnants    in    peridental 
membrane  as  source  of  infection, 
496 
etiology,  471 

external  factors,  472 
bacteria,  472 
mechanical  injvny,  472 
tartar  as  a  predisposing 
cause,  473 
general  considerations,  469 
history,  464 

inflammatory  nature,  469 
medical     cooperation     in     systemic 

treatment,  508 
from  neglect  of  antisepsis,  123 
from  nutritional  disorders,  494 
opsonins  and  opsonic  index  in,  512 
"pen"    for    medicinal    applications, 

507 
pericemental  abscess,  500 
pneumococcus  in,  495 
prognosis,  509 
pulp  infection,  398 
pus,  bacteriological  exainination  of. 
502 
pockets,  500 
radiograph,    a    valuable    diagnostic 

aid,  503 
relationship  to  malnutrition,  502 
scahng,  after-treatment,  492_ 

Black's    preparation, 

493 
iodoglycerol,  492 
quinin  sulfate,  493 
Younger's  preparation, 
491 
zinc  chlorid,  493 
asepsis  in,  489 
chemical  aids  in,  491 

Head's  "Tartasol,"  492 
cocain  in,  491 
contraindications  to,  505 
hemorrhage,  control  of,  490 
hot  air  in,  490 
instruments,   480 

dentate  scalers,  488 
handles,  selection  of,  486 
temper,  486 


IXDh'X 


029 


Pyorrhea,     scaling    insfruiucnts,     tyix's, 
4St3 
novocain   in,   491 
pain,  control  of,  490 
preparatory  details,  4S9 
serunial  tartar  in,  503 
splinting  loose  teeth,  oO? 
terminology,  468 
theories,    early  American,  on,  4()(3 

French,  on,  464 
treatment,  486 
iodin,  489 

removal  of  deposits,  489 
systemic,  505 
vaccines,  509 
uratic  deposits  in,  503 
vaccines  in,  509 

method  of  inoculation,  517 
PjTOZone,  for  bleaching  teeth,  535 


R 


Radiograph  diagnosis  in  chronic  apical 
abscess,  449 
in    malformed    and    malplaced 

teeth,  596 
in  orthodontia,  738 
in  pyorrhea  alveolaris,  503 
Record  charts,  136 

keeping,  advantages,  139 
Regulating  appliances,  739 

adjustment  and  operation,  768 
Angle's,  742 

chin  retractor,  752 
clamp-bands,  745 
expansion  arches,   743 
plain,  743 
ribbed,  744 
threadless,  745 
headgear,  750 
jack-screws,  749 
ligature  wire,  brass,  747 
retaining  tubes,  747 
rubber  strips,  747 
sheath-hooks,  745 
spring  levers,  750 
traction  bar,  750 
screws,  749 
clamp-bands,   770 
cementing,  771 
gaining  space  for,  772 
mistakes,  771 
sheaths,  772 
combination  adjusted,   775 
plain  arch,  777 
notched  arch,  777 
combination   for  intermaxillary 

anchorage,  780 
combinations,  miscellaneous,  7S2 
double  rotation,  787 
drawing  tooth  into  line  of 

occlusion,  788 
jackscrews,  786 
levers,  787 
in  relapses,  787 
traction  screws,  782 
in  canines,  782 
59 


Regulating    aijpliances,      combinations, 
traction    in    jirenio- 
lars,  785 
in     shortening    lateral 
half  of  arch,  785 
widening  distance  between 
deciduous  canines,  788 
expansion  arch,  769,  774 
reinforced,  781 
gratlual  adjustment,  779 
individual,   739 
materials  for  construction,  741 
plain  bands,  773 
ready-made,   740 
for  retention.    See  Retention, 
soldering,  757 
teeth.     See  Orthodontia, 
wire  ligatures,  774 
forms  of,  775 
Replantation  of  abscessed  teeth,  450 

of  teeth,  antiseptic  precautions,  127. 

See  also  Plantation, 
indications  for,   649 
technicjue,   649 
terminology,   646 
Resorption  of  roots  of  permanent  teeth, 

treatment,  456 

Retention  in  orthodontia,  789 

cases  of  Class  I,  791 

cases  of  Class  II,  803 

canines,   806 

incisors,   807 

intermaxillary  retainers,  803 
Griinberg's    modification, 
805 
lingual     arch    for    maintaining 

width,  805 
molars,  807 
l^lates    for    maintaining    width, 

806 
spurs,  set  in  fillings,  805 
cases  of  Class  III,  807 
permanent  devices,   792 

for  aligning  canines,  796 
incisors,   794 

Bunker's  device,  795 
bands  and  spurs,  793 
lingual  arch,  789 
for  molars,  797 
plates,  797 

for  rotated  incisors,  793 
section     wires,     for     preserving 

space,  793 
spurs,  793 

working  retainer,  800 
principles,  790 
temporary  devices,   791 
time  required,  789 
Retrusions,  upper  dental  and  maxillary, 

887 
Retzius,  brown  bands  of,  69 
Rhinology  and  orthodontia,  cooperation 

of,  701 
Riggs'  disease.    See  Pyorrhea  alveolaris. 
Robinson's  remed}'  for  sensitive  dentin, 

151 
Rollins'  tubular  knife  for  abscess  treat- 
ment ,   442 


930 


IMJEX 


Root,  apex,  amputation  of,  449 
canals,  o91.    .SVr  also  Pulp, 
abnormal  shaijcs  of,  420 
clcaninfi;,  411 

antiseptic  precautions,  415 

in  bicuspids,  413 

Kerrs  reamers  for,  413 

lactic  acid  for,  413,  424 

in  molars,  413 

in  single-rooted  teeth,  413 

sodium  |)otassium  for,  414,  424 

sulfuric  acid  for,  413,  424 
dressing,    manner    of    manipulating 
broaches,  459 

after  pulp  removal,  401 

temporary  germicidal,  457 
filling  of,  456 

for  bleached  teeth,  529,  533 

broaches  for,  459 

Canada  balsam,  54S 

chloropercha,  457 

cotton  and  chloropercha,  459 
and  zinc  oxychlorid,  459 

covering  for,  462 

in  deciduous  teeth,  462,  6S0 

embalming  paste,  457,  461 

eucalyjito-percha,  457 

floss  silk  and  chloropercha,  459 

gutta-percha,  312,  456 

cones,  manner  of  fitting,  460 

immediate,  paste  for,  401 

with  inaccessible  apices,  461 

measuring  length  of  root  to  be 
filled,  460 

normal,    tapering,    well-opened, 
459 

with  open  foramina,  460 

paraffin,  458 

pulp  digestion  preceding,  463 

Rhein's    mummifying    method, 
461 

removal  of  old,  431 

salol,  458 

Soderberg's  mummifving  paste, 
461,  463 

wax,  4.58 

zinc  oxychlorid,  457 
normal  shapes  of,  416 
opening,  accidents  in,  424 
perforation  of,  424 

filling,  455 
removal  of  broken  instruments  from, 

424 
restoring  lost  continuity  of,  423 
treatment,   415 

in  bleaching  teeth,  530 
..        cement  for  sealing  dressings,  314 

fine  and  tortuous  canals,  421 

formocresol,  422,  430 

gutta-percha  for  sealing  dress- 
ings, 313 

with  vital  pulps,  391 
widening,   Gates-Glidden   drills   for, 
414 

Kerr's  reamers  for,  413 
Roots,  extracting  with  elevator,  581 

relation  to  internal  structures  of  jaw, 
565 


Roots,  various  forms  of,  565,  .568 
Rubber  cup  for  abscessed  gums,  44>> 
dam,  antiseptic  application,  120 

application   in   filling  deciduous 
teeth,   673 

arraniicment  on  face,  197 

in  bleaching  teeth,  .528 

clamjis,   196 

holders,    197 

ligatures,  196 

napkins,  198 

nausea,  200 

placement,   195 

punching,  194 

quality  of  rubber,  192 

sandarac  or  danunar  varnish  for 
securing,   196 

sterilization,  119 

supporter,  197 

syncope,  200 

use,  192 
Rubber  and  gutta-percha,  properties,  310 


S 


Saliva,  ejector,  191 

question  of  antiseptic  action,  118 
role  in  tartar  formation,  480 
Salol  in  filling  pulp  canals  in  deciduous 
teeth,  681 
for  root  canal  filling,  4.58 
Scalers,    135 
Scaling,  135 

teeth,  486 
Schreier's  kalium-natnum  paste  in  bleach- 
ing teeth,  .536 
Scorbutus,     differential    diagnosis    from 

pyorrhea,  .500 
Sensitive    dentin,    treatment,    146.      See 

also  Dentin. 
Separation,  counteracting  soreness  from, 
144 
gradual,  immediate,  or  forcible,  140 
with     base-plate    gutta-percha, 

143 
with  cork,  141 
with  cotton,  140 
with  elastic  rubber,  142 
with  linen  tape,  141 
with  wood,  141 
immediate  or  forcible,  143 
maintaining,  142 
necessary  caution  in,  142 
Separators,  Capwell's  '"single-bow,"  144 
Perry's,    143 
sterilization,  121 
Septicemia  from  abscess,  438,  455 

treatment,  445 
Silk  fio.ss  for  examining  teeth,  138 
Silver  iodid  in  pyorrhea  alveolaris,  for- 
mula, 507 
nitrate  for  cavity  lining,  322 
for  sensitive  dentin,  151 
in  treating  deciduous  teeth,  669 
Sinus,  maxillary,  infection,  571 
Sodium  dioxid  for  bleaching  teeth,  5.36 
Soldering  in  orthodontia,  757 


I  XL)  EX 


931 


Soinnoforni,  150 

Splinting  loose  ti'eth  in  pyurihca,  nOS 
Square  arch,   19 

Stains    in    teeth,    from    metallic    salts, 
bleaching  methods,  o-i2.     /See  also  Dis- 
coloration. 
Stcrihzation,  agents  used,  128 
hands,   133 
instruments,  120 
by  boiling,  131 
Sterilizers,   bciling  water,   133 
Downie's  steam,  122 
Scherings'   formalin,   130 
Sterilizing  solution,  122 
Stratification  bands  in  enamel,  69 
Sulcus,   173 
Sulfur  dioxid  for  bleaching  teeth,  53S 

Kirk's  method,  539 
Sulfuric  acid  in  scaling  teeth,  491 
Supernumerary  teeth,  fourth  molars,  49 
Suprarenin    in     local    anesthesia.      See 

Anesthesia. 
Swelling,  facial,  from  acute  apical  abscess, 

treatment,  445 
Sj-ncope  from  rubber  dam,  200 

treatment,  400 
S^•philis  contracted    through   extraction, 
125 
potassium  iodid  in  acute  apical  ab- 
scess complicated  with,  441 
Syringes,  compound  pressure,  for  cocain 
analgesia  of  dentin,  148 
electric  warm  air,  147 
Farrar's  alveolar  abscess,  444 
hot-air,  146 

hypodermic,  for  local  anesthesia,  634 
for  pressure  anesthesia,  643 


Tartar,  action  on  gingival  tissues,  4S5 

in  betel  nut  chewers,  481 

chemical  nature,  474 

favorite  locations,  476 

formation,  role  of  saliva  in,  480 

nature  of  composition,  479 

physical  characteristics,  475 

as   predisposing   cause  of  pyorrhea 
alveolaris.    See  Pj'orrhea. 

removal,  486 

serumal,  in  pj'orrhea  alveolaris,  503 

solvents  for,  491 

subgingival,  484 
Tartasol,  Head's,  492 
Teeth,   anterior,  selection  of  filling  ma- 
terials for,  329 

apposition,  21 

articulation,  normal,  22 

comparative  anatomy,  57 

deciduous,    management.      See    De- 
ciduous teeth. 

examination  preliminary   to   opera- 
tion, 135 

forms,  18 

genesis,  18 
variations,  53 

functions,   18 


Teeth,  incompleteness  of  development,  53 
influence  on  physiognomj-,  873 
immber  and  classes,  22 
occlusion,  20.    See  also  OccIu.sion. 
pathological  lesions,  55 
permanent,  loss  of,  a  cause  of  mal- 
occlusion,   724 
regulating.    See  Orthodontia, 
relations    of    physiognomj'    to    the 

saving  and  extraction  of,  893 
reversion  to  primitive  tj'pes,  53 
scaling,  135 
separating,  140 

supernumerary,    a    cause    of     mal- 
occlusion, 724 
tardy  eruption,  a  cause  of  malocclu- 
sion, 724 
temperamental  impress  in,  54 
temporary.    See  Deciduous  teeth, 
tissues,  59 
the  tuberculate,  34 
Temperamental  impress  in  teeth,  54 
Temporary  stopping,  318 

Gilbert's,    in    filling    deciduous 
teeth,  676 
Thermal  shock  in  pulps,  392,  395 
Thumb  sucking  a  cause  of  maloccliision, 

724 
Thymol  and  cement  for  pulp    capping, 

394 
Tin  and  its  combinations,  319 
for  fillings,  201,  226 
foil  fillings,  248 

and  amalgam  fillings,  321 
formation  of  cushions  from,  248 
and     gold     fillings,     239,     249, 

321 
indications  for,  320 
preservative  qualities,  320 
shavings,  227 
Tomes,  fibers  of,  90 

granular  layer  of,  87 
Tongue  biting,  a  cause  of  malocclusion, 
725 
pressure  in  occlusion,  699 
Tonics  for  hemophiliacs,  610 
Tonsils,    enlarged    faucial,    a    cause    of 

malocclusion,  721 
Tooth  movement.    See  Orthodontia. 
Toothache  in  children,  treatment,  668 
Toxemia  from  apical  abscess,  452 
Traction  bar  in  orthodontia,  750 

screws  in  orthodontia,  749 
Transplantation  of  teeth,  antiseptic  pre- 
cautions in,  127.     See  also  Plan- 
tation, 
indications  for,  650 
terminolog}',  646 
Trephines  for  abscess  treatment,  442 
Trichloracetic    acid    in     scaling    teeth, 

491 
Trimmers,  gingival  margin,  162 

gutta-percha,  316 
Tuberculosis,    prevention   bj'   oral   anti- 
sepsis, 125 
Tumors,  rhomboid  infiltration  anesthesia 

for  removal,  644 
Tj-pes  of  teeth,  18 


932 


JMjEX 


Vaccine  Ihcrapy  in  oral  infection,  a(>9 
isolating;  bacteria  for,  511 
method  of  niakint;;  inoculation,  .")17 

Vaccines,  preparation,  511 

\'-arch,  rounded,  20 

Varnishes  for  cavity  lining,  322 

Vertebrates,  teeth  in,  17,  30,  34 


AVax,   Taggart's    automatic     apparatus, 
37<J 

model  for  cast  inlay.     .Sec  Inlay. 

for  root  canal  filling,  45.S 

treatment,   371 
Weaver  ])ressure  svringe,  149 
Weil,  layer  of,  01  "" 
Wheels  ifor  cavity  preparation,  1154 
Wounds,  treatment  to  prevent  infection, 
127 


W 


Wax    for     casting,     automatic     elect  rii 
heater  for  softening,  372 
burning  out,  379 
Taggart's,  367 


Zinc  chlorid  for  sensitive  dentin,  151 
oxychlorid.     See  Cements, 
oxyphoephate.     .SVe  Cements. 
j)hosj)hates.     .Sec  Cements. 


M  '.'  ■:i  (i 


-.'<   •'    ,'''*'^'! 


